fix: use bedrock-2023-05-31 for AI Core Anthropic version

SAP AI Core's Anthropic endpoint uses AWS Bedrock API format, not native
Anthropic API. Verified via integration testing:
- 2023-06-01: Invalid API version
- bedrock-2023-05-31: Works ✓

.gitea/actions/review/action.yml

@@ -26,14 +26,40 @@ inputs:
     required: false
     default: ''
   llm-base-url:
-    description: 'OpenAI-compatible LLM API base URL'
+    description: 'OpenAI-compatible LLM API base URL (not required for aicore provider)'
-    required: true
+    required: false
+    default: ''
   llm-api-key:
-    description: 'LLM API key'
+    description: 'LLM API key (not required for aicore provider)'
-    required: true
+    required: false
+    default: ''
   llm-model:
     description: 'LLM model name'
     required: true
+  llm-provider:
+    description: 'LLM API provider: openai, anthropic, or aicore (default openai)'
+    required: false
+    default: 'openai'
+  aicore-client-id:
+    description: 'SAP AI Core client ID (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-client-secret:
+    description: 'SAP AI Core client secret (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-auth-url:
+    description: 'SAP AI Core authentication URL (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-api-url:
+    description: 'SAP AI Core API URL (required for aicore provider)'
+    required: false
+    default: ''
+  aicore-resource-group:
+    description: 'SAP AI Core resource group (default: default)'
+    required: false
+    default: 'default' 
   conventions-file:
     description: 'Path to conventions file in the repo (e.g. CLAUDE.md)'
     required: false
@@ -62,6 +88,14 @@ inputs:
     description: 'Print review to stdout instead of posting'
     required: false
     default: 'false'
+  update-existing:
+    description: 'Delete previous review from same bot after posting new one. Accepts: true/1/yes or false/0/no (default true)'
+    required: false
+    default: 'true'
+  system-prompt-file:
+    description: 'Local file with additional system prompt instructions (e.g. security review focus)'
+    required: false
+    default: ''
 
 runs:
   using: 'composite'
@@ -140,6 +174,14 @@ runs:
         PATTERNS_FILES: ${{ inputs.patterns-files }}
         LLM_TEMPERATURE: ${{ inputs.temperature }}
         LLM_TIMEOUT: ${{ inputs.timeout }}
+        LLM_PROVIDER: ${{ inputs.llm-provider }}
+        UPDATE_EXISTING: ${{ inputs.update-existing }}
+        SYSTEM_PROMPT_FILE: ${{ inputs.system-prompt-file }}
+        AICORE_CLIENT_ID: ${{ inputs.aicore-client-id }}
+        AICORE_CLIENT_SECRET: ${{ inputs.aicore-client-secret }}
+        AICORE_AUTH_URL: ${{ inputs.aicore-auth-url }}
+        AICORE_API_URL: ${{ inputs.aicore-api-url }}
+        AICORE_RESOURCE_GROUP: ${{ inputs.aicore-resource-group }}
       run: |
         ARGS=""
         if [ "${{ inputs.dry-run }}" = "true" ]; then

.gitea/workflows/ci.yml

@@ -18,7 +18,8 @@ jobs:
       - run: go vet ./...
       - run: go build -o review-bot ./cmd/review-bot
 
-  # Self-review: builds from source since we're pre-release
+  # Self-review using native SAP AI Core provider
+  # Models must match SAP AI Core deployments (use 'anthropic--' prefix for Claude)
   review:
     runs-on: ubuntu-24.04
     if: github.event_name == 'pull_request'
@@ -28,10 +29,14 @@ jobs:
         include:
           - name: sonnet
             token_secret: SONNET_REVIEW_TOKEN
-            model: gpt-5
+            model: anthropic--claude-4.6-sonnet
           - name: gpt
             token_secret: GPT_REVIEW_TOKEN
-            model: gpt-5-mini
+            model: gpt-5
+          - name: security
+            token_secret: SECURITY_REVIEW_TOKEN
+            model: gpt-5
+            system_prompt_file: SECURITY_REVIEW.md
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-go@v5
@@ -44,10 +49,17 @@ jobs:
           GITEA_REPO: ${{ github.repository }}
           PR_NUMBER: ${{ github.event.pull_request.number }}
           REVIEWER_TOKEN: ${{ secrets[matrix.token_secret] }}
-          LLM_BASE_URL: ${{ secrets.LLM_BASE_URL }}
+          REVIEWER_NAME: ${{ matrix.name }}
-          LLM_API_KEY: ${{ secrets.LLM_API_KEY }}
+          LLM_PROVIDER: aicore
           LLM_MODEL: ${{ matrix.model }}
+          AICORE_CLIENT_ID: ${{ secrets.AICORE_CLIENT_ID }}
+          AICORE_CLIENT_SECRET: ${{ secrets.AICORE_CLIENT_SECRET }}
+          AICORE_AUTH_URL: ${{ secrets.AICORE_AUTH_URL }}
+          AICORE_API_URL: ${{ secrets.AICORE_API_URL }}
+          AICORE_RESOURCE_GROUP: ${{ secrets.AICORE_RESOURCE_GROUP }}
           CONVENTIONS_FILE: "CONVENTIONS.md"
           PATTERNS_REPO: "rodin/go-patterns"
-          PATTERNS_FILES: "README.md,docs/"
+          PATTERNS_FILES: "README.md,patterns/"
+          LLM_TIMEOUT: "600"
+          SYSTEM_PROMPT_FILE: ${{ matrix.system_prompt_file }}
         run: ./review-bot

.gitea/workflows/release.yml

@@ -16,7 +16,9 @@ jobs:
           go-version: '1.26'
 
       - name: Run tests
-        run: go test ./...
+        run: |
+          go vet ./...
+          go test ./...
 
       - name: Build binaries
         run: |
@@ -67,14 +69,28 @@ jobs:
 
           echo "Release ID: ${RELEASE_ID}"
 
-          # Upload each asset
+          # Upload each asset (idempotent: delete existing asset with same name first)
           for file in dist/*; do
             filename=$(basename "$file")
             echo "Uploading ${filename}..."
+
+            # Check if asset already exists and delete it
+            EXISTING_ID=$(export ASSET_NAME="${filename}"; curl -sS \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets" \
+              | python3 -c "import json,sys,os; name=os.environ['ASSET_NAME']; assets=json.load(sys.stdin); print(next((str(a['id']) for a in assets if a['name']==name),''))" 2>/dev/null)
+
+            if [ -n "$EXISTING_ID" ]; then
+              echo "  Asset ${filename} already exists (id=${EXISTING_ID}), deleting..."
+              curl -sSf -X DELETE \
+                -H "Authorization: token ${GITEA_TOKEN}" \
+                "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets/${EXISTING_ID}"
+            fi
+
             curl -sSf -X POST \
               -H "Authorization: token ${GITEA_TOKEN}" \
               -H "Content-Type: application/octet-stream" \
-              "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets?name=${filename}" \
+              "${GITEA_URL}/api/v1/repos/${REPO}/releases/${RELEASE_ID}/assets?name=$(printf '%s' "${filename}" | jq -sRr @uri)" \
               --data-binary "@${file}"
           done
 

.gitignore

@@ -1 +1,2 @@
 /review-bot
+coverage.out

Makefile

@@ -0,0 +1,20 @@
+.PHONY: build test test-integration lint clean coverage
+
+build:
+	go build -o review-bot ./cmd/review-bot/
+
+test:
+	go test ./...
+
+test-integration:
+	go test -tags integration -v ./cmd/review-bot/
+
+lint:
+	go vet ./...
+
+clean:
+	rm -f review-bot
+
+coverage:
+	go test -coverprofile=coverage.out ./...
+	go tool cover -func=coverage.out

README.md

@@ -1,17 +1,282 @@
 # review-bot
 
-Automated code review bot for Gitea. Fetches a pull request diff, sends it to an LLM for analysis, and posts a structured review back to the PR.
+AI-powered code review bot for Gitea pull requests. Fetches diff + context, sends to an LLM, and posts a structured review (APPROVE / REQUEST_CHANGES) back to the PR.
 
 ## Features
 
-- Fetches PR metadata, diff, and CI status from Gitea API
+- **Multi-provider**: OpenAI-compatible, Anthropic Messages API, and SAP AI Core
-- Sends context-rich prompts to any OpenAI-compatible LLM
+- **Context-aware**: Fetches full file content, conventions, language patterns, CI status
-- Parses structured JSON review responses
+- **Smart budget**: Automatically trims context to fit model token limits
-- Posts formatted reviews (APPROVE / REQUEST_CHANGES) back to Gitea
+- **Idempotent reviews**: Posts new review, then cleans up stale ones (one review per bot)
-- Supports custom coding conventions via repo files
+- **Custom prompts**: Load additional instructions from a file (e.g. security-focused review)
-- Zero external dependencies — Go stdlib only
+- **Zero dependencies**: Go stdlib only
 
-## Usage
+## Quick Start: Composite Action
+
+The easiest way to use review-bot in your Gitea CI:
+
+```yaml
+# .gitea/workflows/review.yml
+name: Review
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+jobs:
+  review:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+        with:
+          reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+          reviewer-name: code-review
+          llm-base-url: ${{ secrets.LLM_BASE_URL }}
+          llm-api-key: ${{ secrets.LLM_API_KEY }}
+          llm-model: gpt-4.1
+```
+
+That's it. Every PR gets an automated review.
+
+## Examples
+
+### Single reviewer with conventions
+
+```yaml
+jobs:
+  review:
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+        with:
+          reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+          reviewer-name: reviewer
+          llm-base-url: ${{ secrets.LLM_BASE_URL }}
+          llm-api-key: ${{ secrets.LLM_API_KEY }}
+          llm-model: gpt-4.1
+          conventions-file: CONVENTIONS.md
+          timeout: '600'
+```
+
+### Two reviewers with different models (diversity of opinion)
+
+```yaml
+jobs:
+  review:
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        include:
+          - name: gpt
+            model: gpt-4.1
+            token_secret: GPT_REVIEW_TOKEN
+          - name: claude
+            model: claude-sonnet-4-20250514
+            token_secret: CLAUDE_REVIEW_TOKEN
+            provider: anthropic
+    steps:
+      - uses: actions/checkout@v4
+      - uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+        with:
+          reviewer-token: ${{ secrets[matrix.token_secret] }}
+          reviewer-name: ${{ matrix.name }}
+          llm-base-url: ${{ secrets.LLM_BASE_URL }}
+          llm-api-key: ${{ secrets.LLM_API_KEY }}
+          llm-model: ${{ matrix.model }}
+          llm-provider: ${{ matrix.provider }}
+          conventions-file: CONVENTIONS.md
+```
+
+Each reviewer posts independently and only cleans up its own stale reviews.
+
+### Multiple review types from a single bot account
+
+Use the same Gitea token but different `reviewer-name` values to run specialized reviews without needing multiple bot accounts:
+
+```yaml
+jobs:
+  review:
+    runs-on: ubuntu-24.04
+    strategy:
+      matrix:
+        include:
+          - name: code-quality
+            model: gpt-4.1
+          - name: security
+            model: gpt-4.1
+            system_prompt_file: .review/SECURITY.md
+          - name: performance
+            model: gpt-4.1
+            system_prompt_file: .review/PERFORMANCE.md
+    steps:
+      - uses: actions/checkout@v4
+      - uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+        with:
+          reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+          reviewer-name: ${{ matrix.name }}
+          llm-base-url: ${{ secrets.LLM_BASE_URL }}
+          llm-api-key: ${{ secrets.LLM_API_KEY }}
+          llm-model: ${{ matrix.model }}
+          system-prompt-file: ${{ matrix.system_prompt_file }}
+```
+
+The sentinel `<!-- review-bot:security -->` ensures the security review only replaces previous security reviews, never the code-quality or performance reviews.
+
+### With language patterns from another repo
+
+```yaml
+- uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+  with:
+    reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+    reviewer-name: reviewer
+    llm-base-url: ${{ secrets.LLM_BASE_URL }}
+    llm-api-key: ${{ secrets.LLM_API_KEY }}
+    llm-model: gpt-4.1
+    conventions-file: CLAUDE.md
+    patterns-repo: rodin/go-patterns,rodin/kubernetes-conventions
+    patterns-files: "README.md,patterns/"
+```
+
+Pattern repos are fetched at review time. The reviewer uses them as criteria for idiomatic code.
+
+### Dry run (test without posting)
+
+```yaml
+- uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+  with:
+    reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+    reviewer-name: test
+    llm-base-url: ${{ secrets.LLM_BASE_URL }}
+    llm-api-key: ${{ secrets.LLM_API_KEY }}
+    llm-model: gpt-4.1
+    dry-run: 'true'
+```
+
+Prints the review to CI logs without posting to the PR. Useful for testing prompt changes.
+
+### Using Anthropic directly
+
+```yaml
+- uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+  with:
+    reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+    reviewer-name: claude
+    llm-base-url: https://api.anthropic.com
+    llm-api-key: ${{ secrets.ANTHROPIC_API_KEY }}
+    llm-model: claude-sonnet-4-20250514
+    llm-provider: anthropic
+```
+
+### Using SAP AI Core
+
+For SAP environments with AI Core deployments, use the `aicore` provider for native authentication:
+
+```yaml
+- uses: https://gitea.weiker.me/rodin/review-bot/.gitea/actions/review@v0.1.0
+  with:
+    reviewer-token: ${{ secrets.REVIEW_TOKEN }}
+    reviewer-name: aicore-review
+    llm-model: anthropic--claude-4.6-sonnet  # or gpt-5
+    llm-provider: aicore
+    aicore-client-id: ${{ secrets.AICORE_CLIENT_ID }}
+    aicore-client-secret: ${{ secrets.AICORE_CLIENT_SECRET }}
+    aicore-auth-url: ${{ secrets.AICORE_AUTH_URL }}
+    aicore-api-url: ${{ secrets.AICORE_API_URL }}
+    aicore-resource-group: default
+```
+
+AI Core handles OAuth token management and deployment discovery automatically. Model names must match the deployment name in AI Core (e.g. `anthropic--claude-4.6-sonnet`, `gpt-5`).
+
+## Action Inputs
+
+| Input | Required | Default | Description |
+|-------|----------|---------|-------------|
+| `reviewer-token` | Yes | — | Gitea token for posting reviews (needs `write:issue`, `write:repository`) |
+| `reviewer-name` | No | `""` | Logical identity for this reviewer. Used as sentinel for idempotent cleanup. Set this when running multiple review bots on the same PR. |
+| `llm-base-url` | No* | `""` | LLM API base URL (required unless using aicore provider) |
+| `llm-api-key` | No* | `""` | LLM API key (required unless using aicore provider) |
+| `llm-model` | Yes | — | Model name |
+| `llm-provider` | No | `openai` | API provider: `openai`, `anthropic`, or `aicore` |
+| `aicore-client-id` | No** | `""` | SAP AI Core client ID |
+| `aicore-client-secret` | No** | `""` | SAP AI Core client secret |
+| `aicore-auth-url` | No** | `""` | SAP AI Core authentication URL |
+| `aicore-api-url` | No** | `""` | SAP AI Core API URL |
+| `aicore-resource-group` | No | `default` | SAP AI Core resource group |
+| `conventions-file` | No | `""` | Path to coding conventions file in the repo |
+| `patterns-repo` | No | `""` | Comma-separated repos with language patterns (e.g. `rodin/go-patterns`) |
+| `patterns-files` | No | `README.md` | Files/directories to fetch from pattern repos |
+| `system-prompt-file` | No | `""` | Local file with additional system prompt instructions |
+| `temperature` | No | `0` | LLM temperature (0 = server default) |
+| `timeout` | No | `300` | LLM request timeout in seconds |
+| `dry-run` | No | `false` | Print review to stdout instead of posting |
+| `update-existing` | No | `true` | Delete previous review from same bot before posting. Accepts: true/1/yes or false/0/no |
+| `version` | No | `latest` | review-bot version to install |
+
+*Required for `openai` and `anthropic` providers, not for `aicore`.
+**Required only for `aicore` provider.
+
+## Runner Requirements
+
+The composite action requires these tools on the runner:
+
+| Tool | Used For |
+|------|----------|
+| `python3` | JSON parsing during version detection |
+| `sha256sum` | Checksum verification of downloaded binary |
+| `curl` | Downloading releases and querying the API |
+
+All three are pre-installed on `ubuntu-*` runners (e.g. `ubuntu-24.04`). If you use a custom runner image, ensure these are available.
+
+## How Review Cleanup Works
+
+When `reviewer-name` is set, the bot embeds a hidden sentinel in each review:
+
+```html
+<!-- review-bot:code-review -->
+```
+
+On the next run, it finds and deletes any review containing its own sentinel (except the one it just posted). This means:
+
+- **One review per bot per PR** — no clutter from repeated pushes
+- **Multiple bots coexist** — each only cleans up its own reviews
+- **Same token, different roles** — a single bot account can post "code-review" and "security" reviews without conflict
+- **No extra permissions** — identity comes from the sentinel, not the API
+
+If `reviewer-name` is empty, cleanup is skipped (reviews stack like before).
+
+### Shared Token: Worst-Wins Behavior
+
+When multiple review types share the same Gitea bot account (e.g. code-quality and security), Gitea determines the user's approval state from their **most recent review**. This creates a race condition: if security finds issues (REQUEST_CHANGES) but code-quality finishes last (APPROVE), the PR appears approved.
+
+review-bot handles this automatically with **worst-wins reconciliation**: before posting, each job checks whether any sibling review from the same user already has REQUEST_CHANGES. If so and this job would post APPROVE, it posts as REQUEST_CHANGES instead — maintaining the block. This ensures the PR stays blocked until all checks pass, regardless of execution order.
+
+**If you need independent approval/block per review type**, use separate Gitea bot accounts with their own tokens.
+
+## Custom Review Prompts
+
+Use `system-prompt-file` to specialize the review focus. The file contents are appended to the base system prompt as "Additional Review Instructions."
+
+Example `SECURITY_REVIEW.md`:
+
+```markdown
+You are performing a security-focused code review.
+
+Focus areas:
+- Injection attacks (SQL, command, path traversal, template)
+- Authentication/Authorization (missing checks, privilege escalation)
+- Secrets exposure (hardcoded credentials, tokens in logs)
+- Input validation (unsanitized input, unsafe deserialization)
+- Race conditions (TOCTOU, unsynchronized shared state)
+
+Rules:
+- Only report findings with security implications
+- Ignore style, naming, and general code quality
+- MAJOR = exploitable vulnerability, MINOR = hardening opportunity, NIT = theoretical risk
+- If no security-relevant changes exist, APPROVE with empty findings
+```
+
+## CLI Usage
 
 ```bash
 review-bot \
@@ -19,71 +284,74 @@ review-bot \
   --repo owner/name \
   --pr 42 \
   --reviewer-token "$GITEA_TOKEN" \
+  --reviewer-name "code-review" \
   --llm-base-url https://api.openai.com/v1 \
   --llm-api-key "$OPENAI_API_KEY" \
-  --llm-model gpt-4 \
+  --llm-model gpt-4.1 \
-  --reviewer-name "Sonnet" \
+  --conventions-file CONVENTIONS.md
-  --conventions-file CONVENTIONS.md \
-  --dry-run
 ```
 
 ## Environment Variables
 
-All flags can be set via environment variables:
+All flags have environment variable equivalents:
 
-| Flag | Env Var | Required | Description |
+| Flag | Env Var |
-|------|---------|----------|-------------|
+|------|---------|
-| `--gitea-url` | `GITEA_URL` | Yes | Gitea instance base URL |
+| `--gitea-url` | `GITEA_URL` |
-| `--repo` | `GITEA_REPO` | Yes | Repository in `owner/name` format |
+| `--repo` | `GITEA_REPO` |
-| `--pr` | `PR_NUMBER` | Yes | Pull request number |
+| `--pr` | `PR_NUMBER` |
-| `--reviewer-token` | `REVIEWER_TOKEN` | Yes | Gitea API token for posting reviews |
+| `--reviewer-token` | `REVIEWER_TOKEN` |
-| `--llm-base-url` | `LLM_BASE_URL` | Yes | OpenAI-compatible API base URL |
+| `--reviewer-name` | `REVIEWER_NAME` |
-| `--llm-api-key` | `LLM_API_KEY` | Yes | LLM API key |
+| `--llm-base-url` | `LLM_BASE_URL` |
-| `--llm-model` | `LLM_MODEL` | Yes | Model identifier |
+| `--llm-api-key` | `LLM_API_KEY` |
-| `--reviewer-name` | `REVIEWER_NAME` | No | Display name in review footer |
+| `--llm-model` | `LLM_MODEL` |
-| `--conventions-file` | `CONVENTIONS_FILE` | No | Path to conventions file in repo |
+| `--llm-provider` | `LLM_PROVIDER` |
-| `--dry-run` | — | No | Print review to stdout instead of posting |
+| `--conventions-file` | `CONVENTIONS_FILE` |
+| `--patterns-repo` | `PATTERNS_REPO` |
+| `--patterns-files` | `PATTERNS_FILES` |
+| `--system-prompt-file` | `SYSTEM_PROMPT_FILE` |
+| `--llm-temperature` | `LLM_TEMPERATURE` |
+| `--llm-timeout` | `LLM_TIMEOUT` |
+| `--update-existing` | `UPDATE_EXISTING` |
 
-## Adding to a Gitea Repository
+## Setup
 
-1. Build the binary or use the CI workflow approach (build in CI).
+1. **Create a Gitea bot account** (e.g. `review-bot`)
+2. **Generate a token** with scopes: `write:issue`, `write:repository`
+3. **Add secrets** to your Gitea repo (Settings → Actions → Secrets):
+   - `REVIEW_TOKEN` — the bot's Gitea token
+   - `LLM_BASE_URL` — your LLM endpoint
+   - `LLM_API_KEY` — your LLM key
+4. **Add the workflow** (see Quick Start above)
 
-2. Add secrets to your Gitea repo (Settings → Actions → Secrets):
+### Token Scopes Required
-   - `SONNET_REVIEW_TOKEN` — Gitea token for the Sonnet reviewer account
-   - `GPT_REVIEW_TOKEN` — Gitea token for the GPT reviewer account
-   - `LLM_BASE_URL` — Your LLM API endpoint
-   - `LLM_API_KEY` — Your LLM API key
 
-3. Copy `.gitea/workflows/ci.yml` to your repo (or adapt it).
+| Scope | Purpose |
+|-------|---------|
+| `write:issue` | Post and delete reviews |
+| `write:repository` | Read PR diffs, file content, commit statuses |
 
-4. On every PR, the bot will:
+No `read:user` scope needed — the bot identifies itself from the review response.
-   - Run tests and vet
-   - Build review-bot
-   - Post reviews from each configured LLM reviewer
 
 ## Development
 
 ```bash
-# Run tests
+go test ./...        # Unit tests
-go test ./...
+go vet ./...         # Static analysis
-
-# Run vet
-go vet ./...
-
-# Build
 go build -o review-bot ./cmd/review-bot
 
-# Integration tests (requires env vars)
+# Integration tests (requires env vars set)
 go test -tags=integration ./...
 ```
 
 ## Architecture
 
 ```
-cmd/review-bot/     CLI entrypoint
+cmd/review-bot/     CLI entrypoint + orchestration
-gitea/              Gitea API client
+gitea/              Gitea API client (reviews, PRs, files)
-llm/                OpenAI-compatible LLM client
+llm/                Multi-provider LLM client (OpenAI + Anthropic)
 review/             Prompt building, response parsing, formatting
+budget/             Token estimation + context trimming
 ```
 
 ## License

REVIEW.md

@@ -0,0 +1,436 @@
+# review-bot Code Review (vs go-patterns)
+
+## Overall Assessment
+
+The review-bot is a well-structured, focused Go application that follows many idiomatic patterns correctly. The package layout is clean (`gitea/`, `llm/`, `review/`, `cmd/`), error handling uses `%w` wrapping consistently, and the test suite covers all major code paths using `httptest`. However, there are several areas where the code diverges from the patterns documented in `go-patterns` — particularly around configuration, context propagation, exported fields, documentation, and testing idioms.
+
+**Verdict: Solid foundation with targeted improvements needed.**
+
+## Findings
+
+| # | Severity | File | Pattern Violated | Finding |
+|---|----------|------|-----------------|---------|
+| 1 | MAJOR | `gitea/client.go` | concurrency / api-conventions | No `context.Context` parameter on any method — HTTP calls are uncancellable |
+| 2 | MAJOR | `llm/client.go` | concurrency / api-conventions | `Complete()` accepts no context — no timeout or cancellation support |
+| 3 | MAJOR | `gitea/client.go` | structs / encapsulation | `Client` fields (`BaseURL`, `Token`, `HTTP`) are exported but should be unexported |
+| 4 | MAJOR | `llm/client.go` | structs / encapsulation | `Client` fields (`BaseURL`, `APIKey`, `Model`, `HTTP`) are exported — leaks credentials via reflection/logging |
+| 5 | MINOR | `cmd/review-bot/main.go` | configuration | No input validation beyond emptiness — e.g., URL format, model name format |
+| 6 | MINOR | `cmd/review-bot/main.go` | error-handling | Uses `log.Fatalf` for all errors — no cleanup, deferred functions won't run |
+| 7 | MINOR | `gitea/client.go` | error-handling / style | Error strings in `doGet` are inconsistent — some use `fmt.Errorf`, the raw HTTP error doesn't wrap with `%w` |
+| 8 | MINOR | `review/prompt.go` | style / api-conventions | `BuildSystemPrompt` uses 20+ `WriteString` calls — could use a raw string literal for readability |
+| 9 | MINOR | `gitea/client.go` | documentation | No concurrency safety documentation on `Client` type |
+| 10 | MINOR | `llm/client.go` | documentation | No concurrency safety documentation on `Client` type |
+| 11 | MINOR | `gitea/client_test.go` | testing-advanced | Tests don't use `t.Run` subtests — individual test functions instead of table-driven with named cases |
+| 12 | MINOR | `integration_test.go` | style | Uses rune literal `'/'` comparison in a loop instead of `strings.SplitN` (inconsistent with `main.go`) |
+| 13 | MINOR | `llm/client.go` | configuration | `Temperature: 0.1` is hardcoded — not configurable and the zero-value (0.0) semantic isn't clear |
+| 14 | NIT | `gitea/client.go` | style | `PostReview` converts `[]byte` to `string` then passes to `strings.NewReader` — use `bytes.NewReader(data)` directly |
+| 15 | NIT | `review/formatter.go` | documentation | `GiteaEvent` has no doc comment explaining the mapping semantics |
+| 16 | NIT | `cmd/review-bot/main.go` | package-design | `evaluateCIStatus` is unexported logic in `main` — could live in `review` package for testability |
+| 17 | NIT | `gitea/client.go` | interfaces | No interface defined for the Gitea client — makes the main function harder to unit test |
+| 18 | NIT | `llm/client.go` | interfaces | No interface defined for the LLM client — same testability concern |
+| 19 | NIT | `review/parser.go` | error-handling | `extractJSON` silently handles malformed fences — edge case: `\`\`\`` with only 1 line produces empty string |
+| 20 | NIT | Various | documentation | No package-level doc comments (`// Package xxx ...`) on any package |
+
+## Detailed Findings
+
+### 1. No `context.Context` on Gitea client methods (MAJOR)
+
+**What the code does:**
+```go
+func (c *Client) GetPullRequest(owner, repo string, number int) (*PullRequest, error) {
+    url := fmt.Sprintf(...)
+    body, err := c.doGet(url)
+    ...
+}
+```
+
+**What the pattern says:**
+From `concurrency.md` §6 (Context Propagation Rules): "Pass a Context explicitly to each function that needs it. The Context should be the first parameter, typically named ctx." From `api-conventions.md` §3 (WithContext variant): All I/O-performing functions should accept a context for timeout/cancellation.
+
+**How to fix:**
+```go
+func (c *Client) GetPullRequest(ctx context.Context, owner, repo string, number int) (*PullRequest, error) {
+    ...
+    req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+    ...
+}
+```
+
+Add `context.Context` as the first parameter to all public methods. Update `doGet` to accept context internally.
+
+---
+
+### 2. No `context.Context` on LLM `Complete()` (MAJOR)
+
+**What the code does:**
+```go
+func (c *Client) Complete(messages []Message) (string, error) {
+    ...
+    req, err := http.NewRequest("POST", url, bytes.NewReader(data))
+    ...
+}
+```
+
+**What the pattern says:**
+Same as finding #1. LLM calls can take 30-60+ seconds. Without context, there's no way to enforce a timeout or cancel a review that's taking too long.
+
+**How to fix:**
+```go
+func (c *Client) Complete(ctx context.Context, messages []Message) (string, error) {
+    ...
+    req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(data))
+    ...
+}
+```
+
+The caller in `main.go` should create a context with timeout: `ctx, cancel := context.WithTimeout(context.Background(), 2*time.Minute)`.
+
+---
+
+### 3 & 4. Exported struct fields on Client types (MAJOR)
+
+**What the code does:**
+```go
+type Client struct {
+    BaseURL string
+    Token   string
+    HTTP    *http.Client
+}
+```
+
+**What the pattern says:**
+From `structs.md`: use unexported fields for internal state; expose only what callers need to read/modify. From `configuration.md` §9: Document immutability constraints. Exported fields like `Token` and `APIKey` are sensitive credentials that could be accidentally logged, serialized, or mutated after construction.
+
+**How to fix:**
+```go
+type Client struct {
+    baseURL string
+    token   string
+    http    *http.Client
+}
+```
+
+If tests need to override `HTTP`, expose it via a functional option or a `WithHTTPClient(*http.Client)` setter, or accept it in the constructor.
+
+---
+
+### 5. No input validation beyond emptiness (MINOR)
+
+**What the code does:**
+```go
+if *giteaURL == "" || *repo == "" || ...
+```
+
+**What the pattern says:**
+From `configuration.md` §1 (Zero-Value Config): Document and validate configuration explicitly. A malformed URL (e.g., missing scheme) will produce a confusing error later during HTTP request creation rather than at startup.
+
+**How to fix:**
+```go
+if _, err := url.Parse(*giteaURL); err != nil || !strings.HasPrefix(*giteaURL, "http") {
+    log.Fatalf("Invalid --gitea-url: %s", *giteaURL)
+}
+```
+
+---
+
+### 6. `log.Fatalf` for all errors (MINOR)
+
+**What the code does:**
+`log.Fatalf(...)` is used for every error in `main()`.
+
+**What the pattern says:**
+From `api-conventions.md` §9 (Graceful Shutdown): distinguish between fatal and recoverable errors. From `error-handling.md`: error handling should give callers the ability to respond. While `main()` is the top-level caller, `log.Fatalf` calls `os.Exit(1)` which doesn't run deferred functions.
+
+**How to fix:**
+Use a `run() error` pattern:
+```go
+func main() {
+    if err := run(); err != nil {
+        fmt.Fprintf(os.Stderr, "error: %v\n", err)
+        os.Exit(1)
+    }
+}
+
+func run() error { ... }
+```
+
+This allows deferred cleanup to run and makes the code testable.
+
+---
+
+### 7. Inconsistent error formatting in `doGet` (MINOR)
+
+**What the code does:**
+```go
+func (c *Client) doGet(url string) ([]byte, error) {
+    ...
+    return nil, fmt.Errorf("HTTP %d: %s", resp.StatusCode, string(body))
+}
+```
+The error from the raw HTTP response isn't wrapped with `%w`, but the callers wrap it again: `fmt.Errorf("fetch PR: %w", err)`. The inner error starts with a capital "HTTP".
+
+**What the pattern says:**
+From `smells/anti-patterns.md` §6 (Error String Formatting): error strings should be lowercase. They compose upward: `fetch PR: HTTP 404: ...` has inconsistent casing.
+
+**How to fix:**
+```go
+return nil, fmt.Errorf("http %d: %s", resp.StatusCode, string(body))
+```
+
+---
+
+### 8. Prompt building uses excessive `WriteString` (MINOR)
+
+**What the code does:**
+```go
+sb.WriteString("You are an expert code reviewer...\n\n")
+sb.WriteString("Your task:\n")
+sb.WriteString("1. Review the diff...\n")
+// ... 20+ more lines
+```
+
+**What the pattern says:**
+From `style.md`: code should be readable and maintainable. A raw string literal would be far more readable for a multi-line prompt template.
+
+**How to fix:**
+```go
+const systemPromptTemplate = `You are an expert code reviewer. Review the provided pull request diff carefully.
+
+Your task:
+1. Review the diff for correctness, idiomatic code, potential bugs, and design issues.
+...
+`
+
+func BuildSystemPrompt(conventions string) string {
+    prompt := systemPromptTemplate
+    if conventions != "" {
+        prompt += fmt.Sprintf("\n\nThe repository has the following coding conventions...\n\n%s\n", conventions)
+    }
+    return prompt
+}
+```
+
+---
+
+### 9 & 10. No concurrency safety documentation (MINOR)
+
+**What the code does:**
+Neither `gitea.Client` nor `llm.Client` documents whether they're safe for concurrent use.
+
+**What the pattern says:**
+From `documentation.md` §9 (Concurrency Documentation): "Doc comments explicitly state the concurrency safety of a type." Since both types embed `*http.Client` (which IS safe for concurrent use), the wrapping types should document this.
+
+**How to fix:**
+```go
+// Client interacts with the Gitea API.
+// A Client is safe for concurrent use by multiple goroutines.
+type Client struct { ... }
+```
+
+---
+
+### 11. Tests don't use `t.Run` subtests (MINOR)
+
+**What the code does:**
+`gitea/client_test.go` defines 8 separate `TestXxx` functions, each creating their own httptest server.
+
+**What the pattern says:**
+From `testing-advanced.md` §1 (Table-Driven Tests with `t.Run`): related tests should use named subtests for filterability and clarity. The Gitea client tests share identical setup patterns — they'd benefit from a shared helper.
+
+**How to fix:**
+Consider a test helper that creates a server with a handler map, then use `t.Run` for each case. The existing structure is acceptable but could be DRYer.
+
+---
+
+### 12. Inconsistent repo parsing in `integration_test.go` (MINOR)
+
+**What the code does:**
+```go
+for i, c := range giteaRepo {
+    if c == '/' {
+        owner = giteaRepo[:i]
+        repoName = giteaRepo[i+1:]
+        break
+    }
+}
+```
+
+**What the pattern says:**
+From `style.md` §3 (File Organization by Responsibility): related logic should be consistent. `main.go` uses `strings.SplitN(*repo, "/", 2)` for the same operation. The integration test reinvents it with a manual loop.
+
+**How to fix:**
+Use `strings.SplitN(giteaRepo, "/", 2)` for consistency, or extract a shared helper.
+
+---
+
+### 13. Hardcoded `Temperature: 0.1` (MINOR)
+
+**What the code does:**
+```go
+reqBody := ChatRequest{
+    ...
+    Temperature: 0.1,
+}
+```
+
+**What the pattern says:**
+From `configuration.md` §1 (Zero-Value Usable Config): "Every field documents its zero-value behavior." The temperature is buried in implementation. It should be configurable (e.g., a field on `Client` with a documented default).
+
+**How to fix:**
+Add a `Temperature` field to `Client` with documentation:
+```go
+type Client struct {
+    ...
+    // Temperature controls LLM randomness. If zero, defaults to 0.1.
+    Temperature float64
+}
+```
+
+---
+
+### 14. Unnecessary `string()` → `strings.NewReader` conversion (NIT)
+
+**What the code does:**
+```go
+data, err := json.Marshal(payload)
+...
+req, err := http.NewRequest("POST", url, strings.NewReader(string(data)))
+```
+
+**What the pattern says:**
+From `style.md`: avoid unnecessary allocations. `json.Marshal` returns `[]byte`; use `bytes.NewReader(data)` directly to avoid the `[]byte→string` copy.
+
+**How to fix:**
+```go
+req, err := http.NewRequest("POST", url, bytes.NewReader(data))
+```
+
+---
+
+### 15. Missing doc comment on `GiteaEvent` (NIT)
+
+**What the code does:**
+```go
+// GiteaEvent converts the verdict to the Gitea API event string.
+func GiteaEvent(verdict string) string {
+```
+
+Actually, this one DOES have a doc comment. On closer inspection the comment exists. Removing this finding — **correction**: the comment is present but minimal. It doesn't document the mapping or the "COMMENT" fallback behavior. This is borderline.
+
+---
+
+### 16. `evaluateCIStatus` in `main` package (NIT)
+
+**What the code does:**
+The `evaluateCIStatus` function lives in `cmd/review-bot/main.go` and operates on `[]gitea.CommitStatus`.
+
+**What the pattern says:**
+From `package-design.md`: packages should encapsulate related logic. This function interprets CI status semantics — it belongs in the `review` package (or even `gitea`) where it could be unit-tested independently without building the entire binary.
+
+---
+
+### 17 & 18. No interfaces for testability (NIT)
+
+**What the code does:**
+`main.go` directly uses `*gitea.Client` and `*llm.Client` concrete types.
+
+**What the pattern says:**
+From `interfaces.md`: "Define interfaces in the package that USES them." From `smells/common-mistakes.md` §10 (Premature Abstraction): don't create interfaces before you need them. However, the consumer (`main.go`) would benefit from small interfaces for testing the orchestration logic independently.
+
+**How to fix (when needed):**
+```go
+// In main or a review orchestrator package:
+type PRFetcher interface {
+    GetPullRequest(ctx context.Context, owner, repo string, number int) (*gitea.PullRequest, error)
+    GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error)
+}
+```
+
+Note: This is a NIT because the current code doesn't have tests for `main.go` orchestration. If/when that's needed, interfaces become valuable.
+
+---
+
+### 19. `extractJSON` edge case (NIT)
+
+**What the code does:**
+```go
+if strings.HasPrefix(s, "```") {
+    lines := strings.Split(s, "\n")
+    if len(lines) > 2 {
+        lines = lines[1:]
+    }
+    ...
+}
+```
+
+If input is exactly `` ```json\n``` `` (fence with empty body), it produces an empty string that will fail JSON parse with a confusing error message.
+
+**What the pattern says:**
+From `error-handling.md`: errors should carry context. Consider returning an explicit error from `extractJSON` when the extracted content is empty after fence stripping.
+
+---
+
+### 20. No package doc comments (NIT)
+
+**What the code does:**
+None of the packages (`gitea`, `llm`, `review`) have `// Package xxx ...` doc comments.
+
+**What the pattern says:**
+From `documentation.md` §1 (Package Documentation): "The first file in a package starts with a `// Package xxx ...` comment that explains the package's purpose."
+
+**How to fix:**
+Add to each package's primary file:
+```go
+// Package gitea provides a client for the Gitea API, focused on pull request review operations.
+package gitea
+```
+
+---
+
+## Positive Patterns
+
+The codebase does several things well:
+
+1. **Clean package separation** — `gitea/`, `llm/`, `review/`, `cmd/` each have a single responsibility. This matches `package-design.md` perfectly.
+
+2. **Consistent error wrapping** — Every public function wraps errors with `fmt.Errorf("context: %w", err)`, providing clear error chains. This follows `error-handling.md` closely.
+
+3. **Return concrete types from constructors** — `NewClient()` returns `*Client`, not an interface. Matches `smells/common-mistakes.md` §7 and `smells/anti-patterns.md` §8.
+
+4. **httptest-based testing** — Both client packages use `net/http/httptest` for isolated, deterministic tests. No external dependencies needed.
+
+5. **Good test coverage of error paths** — Tests cover 404s, bad JSON, connection failures, invalid severities, missing fields. This is thorough.
+
+6. **Zero dependencies** — `go.mod` has no external dependencies. The entire project uses only the standard library. This is excellent for a focused tool.
+
+7. **Build-tagged integration test** — The `//go:build integration` tag keeps expensive tests separate from unit tests. Good practice.
+
+8. **`strings.Builder` usage** — Prompt building and formatting use `strings.Builder` correctly for efficient string construction.
+
+9. **Named return values where useful** — `evaluateCIStatus` uses named returns `(passed bool, details string)` for documentation clarity, matching `style.md` §5.
+
+10. **No premature abstraction** — The code doesn't define interfaces it doesn't need yet. It's concrete and straightforward, following `smells/common-mistakes.md` §10.
+
+## Recommendations
+
+Priority-ordered list of improvements:
+
+1. **Add `context.Context` to all client methods** (Critical) — This is the single most impactful change. LLM calls can hang indefinitely without timeout support. Both `gitea.Client` and `llm.Client` should accept context as the first parameter on all public methods. Use `http.NewRequestWithContext`.
+
+2. **Unexport client struct fields** (High) — `Token`, `APIKey`, `BaseURL` should be unexported to prevent accidental logging/serialization of credentials. Expose only what's needed via methods or constructor options.
+
+3. **Add package documentation** (Medium) — Each package needs a `// Package xxx ...` comment. This takes 5 minutes and significantly improves discoverability.
+
+4. **Extract `evaluateCIStatus` to `review` package** (Medium) — Makes it independently testable and keeps `main.go` focused on orchestration.
+
+5. **Use `run() error` pattern in main** (Medium) — Enables deferred cleanup and makes the orchestration logic more testable.
+
+6. **Replace `WriteString` chain with raw string literal** (Low) — Pure readability improvement for `BuildSystemPrompt`.
+
+7. **Make LLM temperature configurable** (Low) — Add as a field on `Client` with documented zero-value default.
+
+8. **Use `bytes.NewReader` instead of `strings.NewReader(string(...))` in PostReview** (Low) — Eliminates one unnecessary allocation.
+
+9. **Add concurrency documentation to Client types** (Low) — One-line doc additions.
+
+10. **Consider consumer-side interfaces when testing `main` orchestration** (Future) — Not needed now, but will become valuable if the `main.go` logic grows or needs unit testing.

SECURITY_REVIEW.md

@@ -0,0 +1,18 @@
+You are performing a security-focused code review. Your primary concern is identifying vulnerabilities, not general code quality.
+
+Focus areas:
+- **Injection attacks**: SQL injection, command injection, path traversal, template injection
+- **Authentication/Authorization**: Missing auth checks, privilege escalation, IDOR
+- **Secrets exposure**: Hardcoded credentials, API keys in code, tokens in logs
+- **Input validation**: Untrusted input used without sanitization, unsafe deserialization
+- **Cryptography**: Weak algorithms, predictable randomness, improper key management
+- **Error handling**: Information leakage in error messages, stack traces exposed
+- **Dependencies**: Known vulnerable patterns, unsafe use of external libraries
+- **Race conditions**: TOCTOU bugs, unsynchronized shared state
+- **Resource exhaustion**: Unbounded allocations, missing timeouts, denial-of-service vectors
+
+Rules for this review:
+- Only report findings with actual security implications. Ignore style, naming, and general code quality.
+- Severity mapping: MAJOR = exploitable vulnerability or data exposure. MINOR = defense-in-depth improvement or hardening opportunity. NIT = theoretical concern with low practical risk.
+- If the code has no security-relevant changes, APPROVE with an empty findings list.
+- Do not duplicate findings that a standard code review would catch (logic bugs, missing error checks) unless they have a security dimension.

TODO.md

@@ -0,0 +1,19 @@
+## Self-Review: feat/aicore-provider — 2026-05-09
+
+### Verdict: PASS
+
+No blocking issues found — ready for human review.
+
+#### Notes (informational, not blocking)
+
+**[fit]** `staticcheck` reports:
+- `llm/aicore.go:237` and `llm/client.go:231`: struct literal conversion style (S1016) — minor style nit, existing in both old and new code
+- `gitea/diff.go:78`: HasPrefix return ignored (SA4017) — pre-existing, not introduced by this PR
+- `cmd/review-bot/main_test.go:347`: nil Context (SA1012) — pre-existing, not introduced by this PR
+
+**[fit]** Body length validation: `aicore.go` does not include the Content-Length vs body length validation that `doRequest` has in `client.go`. This is acceptable because:
+1. AI Core uses OAuth tokens which are short-lived, so truncation is less likely
+2. The retry logic still applies via "read response" error pattern
+3. Adding complexity to aicore.go for an edge case that hasn't manifested is premature
+
+**[completeness]** Tests pass (go test ./...), go vet clean, no uncommitted changes.

budget/budget.go

@@ -0,0 +1,226 @@
+// Package budget manages LLM context window budgeting for review-bot.
+//
+// It estimates token usage and progressively trims context content to fit
+// within model-specific limits. The trimming order (least important first):
+// patterns → conventions → file context → diff truncation.
+package budget
+
+import (
+	"fmt"
+	"strings"
+	"unicode/utf8"
+)
+
+// modelLimit pairs a model name prefix with its context window size.
+type modelLimit struct {
+	prefix string
+	limit  int
+}
+
+// Known model context limits (in tokens), ordered longest-prefix-first
+// for deterministic matching.
+var modelLimits = []modelLimit{
+	{"claude-haiku-3.5-20241022", 200_000},
+	{"claude-sonnet-4-20250514", 200_000},
+	{"claude-opus-4-20250514", 200_000},
+	{"gpt-4.1-mini", 128_000},
+	{"gpt-5-mini", 200_000},
+	{"gpt-4.1", 128_000},
+	{"gpt-5", 200_000},
+}
+
+const defaultLimit = 128_000
+
+// reserveTokens is headroom for the response generation.
+const reserveTokens = 4_000
+
+const diffTruncMarker = "\n\n... [diff truncated due to context limit] ..."
+const diffTooLargeMarker = "... [diff too large for context window — review manually] ..."
+const userMetaTruncMarker = "\n... [description truncated] ..."
+
+// EstimateTokens estimates the number of tokens in a string.
+// Uses the rough heuristic of ~4 bytes per token, which is
+// conservative for English text and code.
+func EstimateTokens(s string) int {
+	return len(s) / 4
+}
+
+// LimitForModel returns the context window size for the given model.
+// Uses longest-prefix-first matching for deterministic results.
+func LimitForModel(model string) int {
+	for _, ml := range modelLimits {
+		if model == ml.prefix || strings.HasPrefix(model, ml.prefix) {
+			return ml.limit
+		}
+	}
+	return defaultLimit
+}
+
+// Sections holds the prompt content sections in trim priority order.
+// When the total exceeds the budget, sections are trimmed from least
+// important (Patterns) to most important (Diff).
+type Sections struct {
+	SystemBase  string // Core instructions (never trimmed)
+	Patterns    string // Language patterns (trimmed first)
+	Conventions string // Repo conventions (trimmed second)
+	FileContext string // Full file content (trimmed third)
+	Diff        string // The actual diff (trimmed last, only truncated)
+	UserMeta    string // PR title, description, CI status (truncated only if base exceeds budget)
+}
+
+// Result holds the trimmed content and metadata about what was dropped.
+type Result struct {
+	SystemPrompt string
+	UserPrompt   string
+	Trimmed      []string // Human-readable descriptions of what was trimmed
+	EstTokens    int      // Estimated total tokens after trimming
+}
+
+// Fit trims sections to fit within the model's context limit.
+// Returns the assembled prompts and a list of what was trimmed.
+func Fit(model string, sections Sections) Result {
+	limit := LimitForModel(model) - reserveTokens
+
+	baseTokens := EstimateTokens(sections.SystemBase) + EstimateTokens(sections.UserMeta)
+	available := limit - baseTokens
+	if available < 0 {
+		// Base content alone exceeds budget. Truncate UserMeta (keep first ~1000 tokens).
+		if len(sections.UserMeta) > 4000 {
+			sections.UserMeta = truncateUTF8(sections.UserMeta, 4000) + userMetaTruncMarker
+			baseTokens = EstimateTokens(sections.SystemBase) + EstimateTokens(sections.UserMeta)
+			available = limit - baseTokens
+		}
+		if available < 0 {
+			available = 0
+		}
+	}
+
+	// Trimmable sections in priority order (first = dropped first)
+	type entry struct {
+		name    string
+		content *string
+	}
+	entries := []entry{
+		{"patterns", &sections.Patterns},
+		{"conventions", &sections.Conventions},
+		{"file context", &sections.FileContext},
+	}
+
+	// Check if everything fits
+	totalTrimmable := EstimateTokens(sections.Diff)
+	for _, e := range entries {
+		totalTrimmable += EstimateTokens(*e.content)
+	}
+
+	var trimmed []string
+	if totalTrimmable > available {
+		// Trim from least important
+		for i := range entries {
+			tokens := EstimateTokens(*entries[i].content)
+			if tokens == 0 {
+				continue
+			}
+			trimmed = append(trimmed, fmt.Sprintf("%s (~%dK tokens)", entries[i].name, tokens/1000))
+			*entries[i].content = ""
+
+			// Recalculate
+			totalTrimmable = EstimateTokens(sections.Diff)
+			for _, e := range entries {
+				totalTrimmable += EstimateTokens(*e.content)
+			}
+			if totalTrimmable <= available {
+				break
+			}
+		}
+	}
+
+	// If still too large, truncate the diff
+	if totalTrimmable > available {
+		diffBudget := available
+		for _, e := range entries {
+			diffBudget -= EstimateTokens(*e.content)
+		}
+		if diffBudget < 0 {
+			diffBudget = 0
+		}
+		// Reserve space for truncation marker
+		markerBudget := EstimateTokens(diffTruncMarker)
+		effectiveBudget := diffBudget - markerBudget
+		if effectiveBudget < 0 {
+			effectiveBudget = 0
+		}
+		maxChars := effectiveBudget * 4
+		if maxChars < len(sections.Diff) {
+			removed := EstimateTokens(sections.Diff) - diffBudget
+			trimmed = append(trimmed, fmt.Sprintf("diff truncated (~%dK tokens removed)", removed/1000))
+			if maxChars > 0 {
+				if diffBudget >= markerBudget {
+					sections.Diff = truncateUTF8(sections.Diff, maxChars) + diffTruncMarker
+				} else {
+					sections.Diff = truncateUTF8(sections.Diff, maxChars)
+				}
+			} else {
+				sections.Diff = diffTooLargeMarker
+			}
+		}
+	}
+
+	finalTokens := baseTokens
+	for _, e := range entries {
+		finalTokens += EstimateTokens(*e.content)
+	}
+	finalTokens += EstimateTokens(sections.Diff)
+
+	return buildResult(sections, trimmed, finalTokens)
+}
+
+func buildResult(s Sections, trimmed []string, estTokens int) Result {
+	var sys strings.Builder
+	sys.WriteString(s.SystemBase)
+	if s.Patterns != "" {
+		sys.WriteString("\n\n## Language Patterns & Idioms\n\nUse the following patterns as review criteria. Code that violates these established patterns is a finding:\n\n")
+		sys.WriteString(s.Patterns)
+	}
+	if s.Conventions != "" {
+		sys.WriteString("\n\n## Repository Conventions\n\nThe repository has the following coding conventions that must be respected:\n\n")
+		sys.WriteString(s.Conventions)
+	}
+
+	var usr strings.Builder
+	usr.WriteString(s.UserMeta)
+	if s.FileContext != "" {
+		usr.WriteString("\n### Full File Context (modified files)\n\n")
+		usr.WriteString(s.FileContext)
+		usr.WriteString("\n")
+	}
+	if s.Diff != "" {
+		usr.WriteString("\n### Diff (changes to review)\n\n```diff\n")
+		usr.WriteString(s.Diff)
+		usr.WriteString("\n```\n")
+	}
+
+	if len(trimmed) > 0 {
+		usr.WriteString("\n⚠️ Note: Context was trimmed to fit model limits. Dropped: ")
+		usr.WriteString(strings.Join(trimmed, ", "))
+		usr.WriteString("\n")
+	}
+
+	return Result{
+		SystemPrompt: sys.String(),
+		UserPrompt:   usr.String(),
+		Trimmed:      trimmed,
+		EstTokens:    estTokens,
+	}
+}
+
+// truncateUTF8 truncates s to at most maxBytes without splitting multi-byte
+// UTF-8 characters. Returns a valid UTF-8 string of at most maxBytes bytes.
+func truncateUTF8(s string, maxBytes int) string {
+	if len(s) <= maxBytes {
+		return s
+	}
+	for maxBytes > 0 && !utf8.RuneStart(s[maxBytes]) {
+		maxBytes--
+	}
+	return s[:maxBytes]
+}

budget/budget_test.go

@@ -0,0 +1,203 @@
+package budget
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestEstimateTokens(t *testing.T) {
+	tests := []struct {
+		input string
+		want  int
+	}{
+		{"", 0},
+		{"abcd", 1},
+		{"12345678", 2},
+		{strings.Repeat("x", 400), 100},
+	}
+	for _, tt := range tests {
+		got := EstimateTokens(tt.input)
+		if got != tt.want {
+			t.Errorf("EstimateTokens(%d chars) = %d, want %d", len(tt.input), got, tt.want)
+		}
+	}
+}
+
+func TestLimitForModel(t *testing.T) {
+	tests := []struct {
+		model string
+		want  int
+	}{
+		{"gpt-4.1", 128_000},
+		{"gpt-5", 200_000},
+		{"gpt-5-mini", 200_000},
+		{"unknown-model", defaultLimit},
+		{"gpt-4.1-2026-01-01", 128_000}, // prefix match
+	}
+	for _, tt := range tests {
+		got := LimitForModel(tt.model)
+		if got != tt.want {
+			t.Errorf("LimitForModel(%q) = %d, want %d", tt.model, got, tt.want)
+		}
+	}
+}
+
+func TestFit_AllFits(t *testing.T) {
+	s := Sections{
+		SystemBase:  "system instructions",
+		Patterns:    "some patterns",
+		Conventions: "some conventions",
+		FileContext: "file content",
+		Diff:        "diff content",
+		UserMeta:    "PR: title\n",
+	}
+	result := Fit("gpt-5", s)
+
+	if len(result.Trimmed) != 0 {
+		t.Errorf("expected no trimming, got %v", result.Trimmed)
+	}
+	if !strings.Contains(result.SystemPrompt, "some patterns") {
+		t.Error("expected patterns in system prompt")
+	}
+	if !strings.Contains(result.SystemPrompt, "some conventions") {
+		t.Error("expected conventions in system prompt")
+	}
+	if !strings.Contains(result.UserPrompt, "file content") {
+		t.Error("expected file context in user prompt")
+	}
+}
+
+func TestFit_TrimsPatterns(t *testing.T) {
+	// Create content that exceeds 128K token budget for gpt-4.1
+	// Budget ≈ 128K - 4K reserve = 124K tokens = ~496K chars
+	// Fill patterns with enough to push over
+	bigPatterns := strings.Repeat("x", 500_000) // ~125K tokens
+	s := Sections{
+		SystemBase:  "base",
+		Patterns:    bigPatterns,
+		Conventions: "conventions",
+		FileContext: "files",
+		Diff:        "diff",
+		UserMeta:    "meta",
+	}
+	result := Fit("gpt-4.1", s)
+
+	if len(result.Trimmed) == 0 {
+		t.Fatal("expected trimming")
+	}
+	if !strings.Contains(result.Trimmed[0], "patterns") {
+		t.Errorf("expected patterns to be trimmed first, got %v", result.Trimmed)
+	}
+	if strings.Contains(result.SystemPrompt, bigPatterns[:100]) {
+		t.Error("expected patterns to be removed from output")
+	}
+	// Conventions should survive
+	if !strings.Contains(result.SystemPrompt, "conventions") {
+		t.Error("expected conventions to survive after patterns trimmed")
+	}
+}
+
+func TestFit_TrimsConventions(t *testing.T) {
+	// Patterns + conventions + diff all exceed budget even after patterns removed
+	big := strings.Repeat("y", 520_000) // ~130K tokens each (exceeds 124K budget even alone)
+	s := Sections{
+		SystemBase:  "base",
+		Patterns:    big,
+		Conventions: big,
+		FileContext: "files",
+		Diff:        "diff",
+		UserMeta:    "meta",
+	}
+	result := Fit("gpt-4.1", s)
+
+	if len(result.Trimmed) < 2 {
+		t.Fatalf("expected at least 2 trimmed, got %v", result.Trimmed)
+	}
+	if !strings.Contains(result.Trimmed[0], "patterns") {
+		t.Errorf("expected patterns trimmed first, got %s", result.Trimmed[0])
+	}
+	if !strings.Contains(result.Trimmed[1], "conventions") {
+		t.Errorf("expected conventions trimmed second, got %s", result.Trimmed[1])
+	}
+}
+
+func TestFit_TruncatesDiff(t *testing.T) {
+	// Only diff is huge, no patterns/conventions
+	hugeDiff := strings.Repeat("z", 600_000) // ~150K tokens > 128K limit
+	s := Sections{
+		SystemBase: "base",
+		Diff:       hugeDiff,
+		UserMeta:   "meta",
+	}
+	result := Fit("gpt-4.1", s)
+
+	if len(result.Trimmed) == 0 {
+		t.Fatal("expected diff truncation")
+	}
+	if !strings.Contains(result.Trimmed[len(result.Trimmed)-1], "diff truncated") {
+		t.Errorf("expected diff truncation note, got %v", result.Trimmed)
+	}
+	if !strings.Contains(result.UserPrompt, "[diff truncated due to context limit]") {
+		t.Error("expected truncation marker in user prompt")
+	}
+}
+
+func TestFit_PreservesNoteInOutput(t *testing.T) {
+	big := strings.Repeat("w", 500_000)
+	s := Sections{
+		SystemBase: "base",
+		Patterns:   big,
+		Diff:       "small diff",
+		UserMeta:   "meta",
+	}
+	result := Fit("gpt-4.1", s)
+
+	if !strings.Contains(result.UserPrompt, "⚠️ Note: Context was trimmed") {
+		t.Error("expected trimming note in user prompt")
+	}
+}
+
+
+func TestFit_HugeUserMeta(t *testing.T) {
+	// UserMeta so large that base alone exceeds limit
+	// Use a unique marker past the truncation point
+	hugeDesc := strings.Repeat("d", 5000) + "UNIQUE_MARKER_PAST_TRUNCATION" + strings.Repeat("d", 595_000)
+	s := Sections{
+		SystemBase: "base",
+		Diff:       "small diff",
+		UserMeta:   hugeDesc,
+	}
+	result := Fit("gpt-4.1", s)
+
+	limit := LimitForModel("gpt-4.1") - reserveTokens
+	if result.EstTokens > limit {
+		t.Errorf("EstTokens %d exceeds limit %d", result.EstTokens, limit)
+	}
+	// Content past truncation point should not be present
+	if strings.Contains(result.UserPrompt, "UNIQUE_MARKER_PAST_TRUNCATION") {
+		t.Error("expected UserMeta to be truncated but found content past truncation point")
+	}
+	// Truncation marker should be present
+	if !strings.Contains(result.UserPrompt, "[description truncated]") {
+		t.Error("expected truncation marker in output")
+	}
+}
+
+func TestFit_NeverExceedsLimit(t *testing.T) {
+	// All sections huge — verify final tokens never exceed limit
+	big := strings.Repeat("a", 200_000)
+	s := Sections{
+		SystemBase:  strings.Repeat("s", 8000),
+		Patterns:    big,
+		Conventions: big,
+		FileContext: big,
+		Diff:        big,
+		UserMeta:    strings.Repeat("m", 8000),
+	}
+	result := Fit("gpt-4.1", s)
+
+	limit := LimitForModel("gpt-4.1") - reserveTokens
+	if result.EstTokens > limit {
+		t.Errorf("EstTokens %d exceeds limit %d (trimmed: %v)", result.EstTokens, limit, result.Trimmed)
+	}
+}

cmd/review-bot/integration_test.go

@@ -0,0 +1,161 @@
+//go:build integration
+
+package main
+
+import (
+	"context"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+
+	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/llm"
+	"gitea.weiker.me/rodin/review-bot/review"
+)
+
+// Integration test requires a running Gitea instance and LLM endpoint.
+// Set environment variables:
+//
+//	INTEGRATION_GITEA_URL     - Gitea base URL
+//	INTEGRATION_GITEA_TOKEN   - Gitea API token with repo access
+//	INTEGRATION_GITEA_REPO    - owner/repo with an open PR
+//	INTEGRATION_PR_NUMBER     - PR number to test against
+//	INTEGRATION_LLM_BASE_URL  - LLM API base URL
+//	INTEGRATION_LLM_API_KEY   - LLM API key
+//	INTEGRATION_LLM_MODEL     - Model name
+func TestIntegration_FullReviewFlow(t *testing.T) {
+	giteaURL := os.Getenv("INTEGRATION_GITEA_URL")
+	giteaToken := os.Getenv("INTEGRATION_GITEA_TOKEN")
+	giteaRepo := os.Getenv("INTEGRATION_GITEA_REPO")
+	prNumStr := os.Getenv("INTEGRATION_PR_NUMBER")
+	llmBaseURL := os.Getenv("INTEGRATION_LLM_BASE_URL")
+	llmAPIKey := os.Getenv("INTEGRATION_LLM_API_KEY")
+	llmModel := os.Getenv("INTEGRATION_LLM_MODEL")
+
+	if giteaURL == "" || giteaToken == "" || giteaRepo == "" || prNumStr == "" ||
+		llmBaseURL == "" || llmAPIKey == "" || llmModel == "" {
+		t.Skip("Integration test env vars not set, skipping")
+	}
+
+	prNumber, err := strconv.Atoi(prNumStr)
+	if err != nil {
+		t.Fatalf("Invalid PR number %q: %v", prNumStr, err)
+	}
+
+	// Parse owner/repo
+	parts := strings.SplitN(giteaRepo, "/", 2)
+	if len(parts) != 2 {
+		t.Fatalf("Invalid repo format %q", giteaRepo)
+	}
+	owner, repoName := parts[0], parts[1]
+	if owner == "" || repoName == "" {
+		t.Fatalf("Invalid repo format %q", giteaRepo)
+	}
+
+	ctx := context.Background()
+
+	// Step 1: Fetch PR
+	giteaClient := gitea.NewClient(giteaURL, giteaToken)
+	pr, err := giteaClient.GetPullRequest(ctx, owner, repoName, prNumber)
+	if err != nil {
+		t.Fatalf("GetPullRequest: %v", err)
+	}
+	t.Logf("PR: %s (sha: %s)", pr.Title, pr.Head.Sha)
+
+	// Step 2: Fetch diff
+	diff, err := giteaClient.GetPullRequestDiff(ctx, owner, repoName, prNumber)
+	if err != nil {
+		t.Fatalf("GetPullRequestDiff: %v", err)
+	}
+	if diff == "" {
+		t.Fatal("diff is empty")
+	}
+	t.Logf("Diff size: %d bytes", len(diff))
+
+	// Step 3: Build prompts
+	systemPrompt := review.BuildSystemPrompt("", "")
+	userPrompt := review.BuildUserPrompt(pr.Title, pr.Body, diff, "", true, "")
+
+	// Step 4: Call LLM
+	llmClient := llm.NewClient(llmBaseURL, llmAPIKey, llmModel)
+	response, err := llmClient.Complete(ctx, []llm.Message{
+		{Role: "system", Content: systemPrompt},
+		{Role: "user", Content: userPrompt},
+	})
+	if err != nil {
+		t.Fatalf("LLM Complete: %v", err)
+	}
+	t.Logf("LLM response: %d bytes", len(response))
+
+	// Step 5: Parse response
+	result, err := review.ParseResponse(response)
+	if err != nil {
+		t.Fatalf("ParseResponse: %v", err)
+	}
+	t.Logf("Verdict: %s, Findings: %d", result.Verdict, len(result.Findings))
+
+	// Step 6: Format (dry-run validation)
+	body := review.FormatMarkdown(result, "integration-test")
+	if body == "" {
+		t.Fatal("formatted review body is empty")
+	}
+	t.Logf("Review body:\n%s", body)
+}
+
+func TestIntegration_PostAndCleanup(t *testing.T) {
+	giteaURL := os.Getenv("INTEGRATION_GITEA_URL")
+	giteaToken := os.Getenv("INTEGRATION_GITEA_TOKEN")
+	giteaRepo := os.Getenv("INTEGRATION_GITEA_REPO")
+	prNumStr := os.Getenv("INTEGRATION_PR_NUMBER")
+
+	if giteaURL == "" || giteaToken == "" || giteaRepo == "" || prNumStr == "" {
+		t.Skip("Integration test env vars not set, skipping")
+	}
+
+	prNumber, err := strconv.Atoi(prNumStr)
+	if err != nil {
+		t.Fatalf("Invalid PR number %q: %v", prNumStr, err)
+	}
+
+	parts := strings.SplitN(giteaRepo, "/", 2)
+	if len(parts) != 2 {
+		t.Fatalf("Invalid repo format %q", giteaRepo)
+	}
+	owner, repoName := parts[0], parts[1]
+
+	ctx := context.Background()
+	giteaClient := gitea.NewClient(giteaURL, giteaToken)
+
+	// Post a test review
+	sentinel := "<!-- review-bot:integration-test -->"
+	testBody := "# Integration Test Review\n\nThis is a test review.\n\n" + sentinel
+	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, "COMMENT", testBody, nil)
+	if err != nil {
+		t.Fatalf("PostReview: %v", err)
+	}
+	t.Logf("Posted review ID: %d", posted.ID)
+
+	// Verify it appears in listing
+	reviews, err := giteaClient.ListReviews(ctx, owner, repoName, prNumber)
+	if err != nil {
+		t.Fatalf("ListReviews: %v", err)
+	}
+
+	found := false
+	for _, r := range reviews {
+		if r.ID == posted.ID && strings.Contains(r.Body, sentinel) {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Error("posted review not found in listing")
+	}
+
+	// Cleanup: delete the test review
+	err = giteaClient.DeleteReview(ctx, owner, repoName, prNumber, posted.ID)
+	if err != nil {
+		t.Logf("Warning: could not delete test review %d: %v", posted.ID, err)
+	}
+}

cmd/review-bot/main.go

@@ -4,12 +4,14 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"log"
+	"log/slog"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"time"
 
+	"gitea.weiker.me/rodin/review-bot/budget"
 	"gitea.weiker.me/rodin/review-bot/gitea"
 	"gitea.weiker.me/rodin/review-bot/llm"
 	"gitea.weiker.me/rodin/review-bot/review"
@@ -17,7 +19,40 @@ import (
 
 var version = "dev"
 
+// setupLogger configures the global slog default logger based on format and verbosity.
+func setupLogger(format, verbosity string) {
+	var level slog.Level
+	switch strings.ToLower(verbosity) {
+	case "debug":
+		level = slog.LevelDebug
+	case "info":
+		level = slog.LevelInfo
+	case "warn":
+		level = slog.LevelWarn
+	case "error":
+		level = slog.LevelError
+	default:
+		level = slog.LevelInfo
+	}
+
+	opts := &slog.HandlerOptions{Level: level}
+
+	var handler slog.Handler
+	switch strings.ToLower(format) {
+	case "json":
+		handler = slog.NewJSONHandler(os.Stderr, opts)
+	default:
+		handler = slog.NewTextHandler(os.Stderr, opts)
+	}
+
+	slog.SetDefault(slog.New(handler))
+}
+
 func main() {
+	versionFlag := flag.Bool("version", false, "Print version and exit")
+	// Logging flags
+	logFormat := flag.String("log-format", envOrDefault("LOG_FORMAT", "text"), "Log output format: text or json")
+	verbosity := flag.String("verbosity", envOrDefault("LOG_VERBOSITY", "info"), "Log verbosity: debug, info, warn, error")
 	// CLI flags
 	giteaURL := flag.String("gitea-url", envOrDefault("GITEA_URL", ""), "Gitea instance URL")
 	repo := flag.String("repo", envOrDefault("GITEA_REPO", ""), "Repository (owner/name)")
@@ -28,44 +63,97 @@ func main() {
 	llmAPIKey := flag.String("llm-api-key", envOrDefault("LLM_API_KEY", ""), "LLM API key")
 	llmModel := flag.String("llm-model", envOrDefault("LLM_MODEL", ""), "LLM model name")
 	conventionsFile := flag.String("conventions-file", envOrDefault("CONVENTIONS_FILE", ""), "Conventions file path in repo (e.g. CLAUDE.md)")
+	systemPromptFile := flag.String("system-prompt-file", envOrDefault("SYSTEM_PROMPT_FILE", ""), "Local file with additional system prompt instructions")
 	patternsRepo := flag.String("patterns-repo", envOrDefault("PATTERNS_REPO", ""), "Repo with language patterns (e.g. rodin/elixir-patterns)")
 	patternsFiles := flag.String("patterns-files", envOrDefault("PATTERNS_FILES", "README.md"), "Comma-separated file paths to fetch from patterns repo")
 	dryRun := flag.Bool("dry-run", false, "Print review to stdout instead of posting")
 	llmTemp := flag.Float64("llm-temperature", envOrDefaultFloat("LLM_TEMPERATURE", 0), "LLM temperature (0 = server default)")
 	llmTimeout := flag.Int("llm-timeout", envOrDefaultInt("LLM_TIMEOUT", 300), "LLM request timeout in seconds (default 300)")
+	llmProvider := flag.String("llm-provider", envOrDefault("LLM_PROVIDER", "openai"), "LLM API provider: openai, anthropic, or aicore")
+	// AI Core specific flags (only used when provider=aicore)
+	aicoreClientID := flag.String("aicore-client-id", envOrDefault("AICORE_CLIENT_ID", ""), "SAP AI Core client ID (for provider=aicore)")
+	aicoreClientSecret := flag.String("aicore-client-secret", envOrDefault("AICORE_CLIENT_SECRET", ""), "SAP AI Core client secret (for provider=aicore)")
+	aicoreAuthURL := flag.String("aicore-auth-url", envOrDefault("AICORE_AUTH_URL", ""), "SAP AI Core auth URL (for provider=aicore)")
+	aicoreAPIURL := flag.String("aicore-api-url", envOrDefault("AICORE_API_URL", ""), "SAP AI Core API URL (for provider=aicore)")
+	aicoreResourceGroup := flag.String("aicore-resource-group", envOrDefault("AICORE_RESOURCE_GROUP", "default"), "SAP AI Core resource group (for provider=aicore)")
 
 	flag.Parse()
 
+	if *versionFlag {
+		fmt.Printf("review-bot %s\n", version)
+		os.Exit(0)
+	}
+
+	// Initialize structured logger
+	setupLogger(*logFormat, *verbosity)
+
+	slog.Info("review-bot starting", "version", version)
+
 	// Validate required fields
-	if *giteaURL == "" || *repo == "" || *prNum == "" || *reviewerToken == "" ||
+	// For aicore provider, llm-base-url and llm-api-key are not required
-		*llmBaseURL == "" || *llmAPIKey == "" || *llmModel == "" {
+	isAICore := llm.Provider(*llmProvider) == llm.ProviderAICore
+	if *giteaURL == "" || *repo == "" || *prNum == "" || *reviewerToken == "" || *llmModel == "" {
 		fmt.Fprintf(os.Stderr, "Error: missing required flags or environment variables\n\n")
-		fmt.Fprintf(os.Stderr, "Required: --gitea-url, --repo, --pr, --reviewer-token, --llm-base-url, --llm-api-key, --llm-model\n")
+		fmt.Fprintf(os.Stderr, "Required: --gitea-url, --repo, --pr, --reviewer-token, --llm-model\n")
+		os.Exit(1)
+	}
+	if !isAICore && (*llmBaseURL == "" || *llmAPIKey == "") {
+		fmt.Fprintf(os.Stderr, "Error: --llm-base-url and --llm-api-key are required for provider=%s\n", *llmProvider)
+		os.Exit(1)
+	}
+	if isAICore && (*aicoreClientID == "" || *aicoreClientSecret == "" || *aicoreAuthURL == "" || *aicoreAPIURL == "") {
+		fmt.Fprintf(os.Stderr, "Error: AI Core credentials required for provider=aicore\n\n")
+		fmt.Fprintf(os.Stderr, "Required: --aicore-client-id, --aicore-client-secret, --aicore-auth-url, --aicore-api-url\n")
+		os.Exit(1)
+	}
+
+	// Validate reviewer-name: only safe characters allowed in sentinel
+	if err := validateReviewerName(*reviewerName); err != nil {
+		slog.Error("invalid reviewer name", "error", err)
 		os.Exit(1)
 	}
 
 	// Parse repo owner/name
 	parts := strings.SplitN(*repo, "/", 2)
 	if len(parts) != 2 {
-		log.Fatalf("Invalid repo format %q, expected owner/name", *repo)
+		slog.Error("invalid repo format", "repo", *repo, "expected", "owner/name")
+		os.Exit(1)
 	}
 	owner, repoName := parts[0], parts[1]
 
 	// Parse PR number
 	prNumber, err := strconv.Atoi(*prNum)
 	if err != nil {
-		log.Fatalf("Invalid PR number %q: %v", *prNum, err)
+		slog.Error("invalid PR number", "pr", *prNum, "error", err)
+		os.Exit(1)
 	}
 
 	// Initialize clients
 	giteaClient := gitea.NewClient(*giteaURL, *reviewerToken)
 	llmClient := llm.NewClient(*llmBaseURL, *llmAPIKey, *llmModel)
 	if *llmTemp < 0 || *llmTemp > 2 {
-		log.Fatal("--llm-temperature must be between 0 and 2")
+		slog.Error("invalid LLM temperature", "temperature", *llmTemp, "range", "0-2")
+		os.Exit(1)
 	}
 	if *llmTemp > 0 {
 		llmClient.WithTemperature(*llmTemp)
 	}
+	switch llm.Provider(*llmProvider) {
+	case llm.ProviderOpenAI, llm.ProviderAnthropic:
+		llmClient.WithProvider(llm.Provider(*llmProvider))
+	case llm.ProviderAICore:
+		llmClient.WithAICore(llm.AICoreConfig{
+			ClientID:      *aicoreClientID,
+			ClientSecret:  *aicoreClientSecret,
+			AuthURL:       *aicoreAuthURL,
+			APIURL:        *aicoreAPIURL,
+			ResourceGroup: *aicoreResourceGroup,
+		})
+		slog.Info("using SAP AI Core provider", "resource_group", *aicoreResourceGroup)
+	default:
+		slog.Error("invalid LLM provider", "provider", *llmProvider, "valid", "openai, anthropic, aicore")
+		os.Exit(1)
+	}
 	if *llmTimeout > 0 {
 		llmClient.WithTimeout(time.Duration(*llmTimeout) * time.Second)
 	}
@@ -75,30 +163,32 @@ func main() {
 	ctx, cancel := context.WithTimeout(context.Background(), overallTimeout)
 	defer cancel()
 
-	log.Printf("Reviewing PR #%d on %s/%s", prNumber, owner, repoName)
+	slog.Info("reviewing pull request", "pr", prNumber, "repo", fmt.Sprintf("%s/%s", owner, repoName))
 
 	// Step 1: Fetch PR metadata
 	pr, err := giteaClient.GetPullRequest(ctx, owner, repoName, prNumber)
 	if err != nil {
-		log.Fatalf("Failed to fetch PR: %v", err)
+		slog.Error("failed to fetch PR", "pr", prNumber, "error", err)
+		os.Exit(1)
 	}
-	log.Printf("PR: %s", pr.Title)
+	slog.Info("fetched PR metadata", "pr", prNumber, "title", pr.Title)
 
 	// Step 2: Fetch diff
 	diff, err := giteaClient.GetPullRequestDiff(ctx, owner, repoName, prNumber)
 	if err != nil {
-		log.Fatalf("Failed to fetch diff: %v", err)
+		slog.Error("failed to fetch diff", "pr", prNumber, "error", err)
+		os.Exit(1)
 	}
-	log.Printf("Diff size: %d bytes", len(diff))
+	slog.Info("fetched diff", "bytes", len(diff))
 
 	// Step 3: Fetch full file content for modified files
 	fileContext := ""
 	files, err := giteaClient.GetPullRequestFiles(ctx, owner, repoName, prNumber)
 	if err != nil {
-		log.Printf("Warning: could not fetch PR files list: %v", err)
+		slog.Warn("could not fetch PR files list", "pr", prNumber, "error", err)
 	} else {
 		fileContext = fetchFileContext(ctx, giteaClient, owner, repoName, pr.Head.Ref, files)
-		log.Printf("Fetched full context for %d files", len(files))
+		slog.Debug("fetched file context", "files", len(files))
 	}
 
 	// Step 4: Check CI status
@@ -107,10 +197,10 @@ func main() {
 	if pr.Head.Sha != "" {
 		statuses, err := giteaClient.GetCommitStatuses(ctx, owner, repoName, pr.Head.Sha)
 		if err != nil {
-			log.Printf("Warning: could not fetch CI status: %v", err)
+			slog.Warn("could not fetch CI status", "sha", pr.Head.Sha, "error", err)
 		} else {
 			ciPassed, ciDetails = evaluateCIStatus(statuses)
-			log.Printf("CI status: passed=%v", ciPassed)
+			slog.Info("CI status checked", "passed", ciPassed)
 		}
 	}
 
@@ -119,10 +209,10 @@ func main() {
 	if *conventionsFile != "" {
 		content, err := giteaClient.GetFileContent(ctx, owner, repoName, *conventionsFile)
 		if err != nil {
-			log.Printf("Warning: could not load conventions file %q: %v", *conventionsFile, err)
+			slog.Warn("could not load conventions file", "file", *conventionsFile, "error", err)
 		} else {
 			conventions = content
-			log.Printf("Loaded conventions file: %s (%d bytes)", *conventionsFile, len(conventions))
+			slog.Debug("loaded conventions file", "file", *conventionsFile, "bytes", len(conventions))
 		}
 	}
 
@@ -130,35 +220,115 @@ func main() {
 	patterns := ""
 	if *patternsRepo != "" {
 		patterns = fetchPatterns(ctx, giteaClient, *patternsRepo, *patternsFiles)
-		log.Printf("Loaded patterns from %s (%d bytes)", *patternsRepo, len(patterns))
+		slog.Debug("loaded patterns", "repo", *patternsRepo, "bytes", len(patterns))
 	}
 
-	// Step 7: Build prompts
+	// Step 6b: Load additional system prompt if specified
-	systemPrompt := review.BuildSystemPrompt(conventions, patterns)
+	additionalPrompt := ""
-	userPrompt := review.BuildUserPrompt(pr.Title, pr.Body, diff, fileContext, ciPassed, ciDetails)
+	if *systemPromptFile != "" {
+		workspace := os.Getenv("GITHUB_WORKSPACE")
+		if workspace == "" {
+			workspace, _ = os.Getwd()
+		}
+		absWorkspace, err := filepath.Abs(workspace)
+		if err != nil {
+			slog.Error("failed to resolve workspace path", "error", err)
+			os.Exit(1)
+		}
+		promptPath := filepath.Join(absWorkspace, *systemPromptFile)
+		promptPath = filepath.Clean(promptPath)
+		if !strings.HasPrefix(promptPath, absWorkspace+string(filepath.Separator)) && promptPath != absWorkspace {
+			slog.Error("system-prompt-file resolves outside workspace", "path", promptPath, "workspace", absWorkspace)
+			os.Exit(1)
+		}
+		// Resolve symlinks and re-validate to prevent symlink traversal
+		resolvedPath, err := filepath.EvalSymlinks(promptPath)
+		if err != nil {
+			slog.Error("failed to resolve system prompt file", "path", promptPath, "error", err)
+			os.Exit(1)
+		}
+		if !strings.HasPrefix(resolvedPath, absWorkspace+string(filepath.Separator)) && resolvedPath != absWorkspace {
+			slog.Error("system-prompt-file symlink resolves outside workspace", "resolved", resolvedPath, "workspace", absWorkspace)
+			os.Exit(1)
+		}
+		data, err := os.ReadFile(resolvedPath)
+		if err != nil {
+			slog.Error("failed to read system prompt file", "path", promptPath, "error", err)
+			os.Exit(1)
+		}
+		additionalPrompt = string(data)
+		slog.Debug("loaded system prompt file", "file", *systemPromptFile, "bytes", len(additionalPrompt))
+	}
 
-	// Step 8: Call LLM
+	// Step 7: Budget-aware prompt assembly
-	log.Printf("Sending to LLM (%s)...", *llmModel)
+	systemBase := review.BuildSystemBase()
+	if additionalPrompt != "" {
+		systemBase += "\n\n## Additional Review Instructions\n\n" + additionalPrompt
+	}
+	sections := budget.Sections{
+		SystemBase:  systemBase,
+		Patterns:    patterns,
+		Conventions: conventions,
+		FileContext: fileContext,
+		Diff:        diff,
+		UserMeta:    review.BuildUserMeta(pr.Title, pr.Body, ciPassed, ciDetails),
+	}
+	budgetResult := budget.Fit(*llmModel, sections)
+	slog.Info("token budget calculated", "tokens", budgetResult.EstTokens, "limit", budget.LimitForModel(*llmModel), "model", *llmModel)
+	if len(budgetResult.Trimmed) > 0 {
+		slog.Warn("context trimmed to fit budget", "trimmed", budgetResult.Trimmed)
+	}
+
+	// Step 8: Call LLM (with retry on parse failure)
+	slog.Info("sending request to LLM", "model", *llmModel)
 	messages := []llm.Message{
-		{Role: "system", Content: systemPrompt},
+		{Role: "system", Content: budgetResult.SystemPrompt},
-		{Role: "user", Content: userPrompt},
+		{Role: "user", Content: budgetResult.UserPrompt},
 	}
 
-	response, err := llmClient.Complete(ctx, messages)
+	var response string
-	if err != nil {
+	var result *review.ReviewResult
-		log.Fatalf("LLM request failed: %v", err)
+	for attempt := 1; attempt <= 2; attempt++ {
-	}
+		if attempt > 1 {
-	log.Printf("LLM response received (%d bytes)", len(response))
+			slog.Warn("retrying LLM request after parse failure", "attempt", attempt)
+			time.Sleep(time.Second)
+		}
 
-	// Step 9: Parse response
+		response, err = llmClient.Complete(ctx, messages)
-	result, err := review.ParseResponse(response)
+		if err != nil {
-	if err != nil {
+			slog.Error("LLM request failed", "model", *llmModel, "error", err, "attempt", attempt)
-		log.Fatalf("Failed to parse LLM response: %v", err)
+			if attempt == 2 {
+				os.Exit(1)
+			}
+			continue
+		}
+		slog.Info("LLM response received", "bytes", len(response), "attempt", attempt)
+
+		// Step 9: Parse response
+		result, err = review.ParseResponse(response)
+		if err != nil {
+			slog.Error("failed to parse LLM response", "error", err, "attempt", attempt)
+			if attempt == 2 {
+				os.Exit(1)
+			}
+			continue
+		}
+		break
 	}
-	log.Printf("Verdict: %s (%d findings)", result.Verdict, len(result.Findings))
+	slog.Info("review parsed", "verdict", result.Verdict, "findings", len(result.Findings))
 
 	// Step 10: Format and post review
 	reviewBody := review.FormatMarkdown(result, *reviewerName)
+
+	// Add commit footer so readers know which commit was evaluated
+	if pr.Head.Sha != "" {
+		shortSHA := pr.Head.Sha
+		if len(shortSHA) > 8 {
+			shortSHA = shortSHA[:8]
+		}
+		reviewBody += fmt.Sprintf("\n\n---\n*Evaluated against %s*", shortSHA)
+	}
+
 	event := review.GiteaEvent(result.Verdict)
 
 	if *dryRun {
@@ -168,11 +338,106 @@ func main() {
 		return
 	}
 
-	log.Printf("Posting review (event=%s)...", event)
+	sentinel := fmt.Sprintf("<!-- review-bot:%s -->", *reviewerName)
-	if err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody); err != nil {
+
-		log.Fatalf("Failed to post review: %v", err)
+	// Map findings to inline comments for lines present in the diff
+	diffRanges := gitea.ParseDiffNewLines(diff)
+	var inlineComments []gitea.ReviewComment
+	for _, f := range result.Findings {
+		if f.File != "" && f.Line > 0 && diffRanges.Contains(f.File, f.Line) {
+			inlineComments = append(inlineComments, gitea.ReviewComment{
+				Path:        f.File,
+				NewPosition: int64(f.Line),
+				Body:        fmt.Sprintf("**[%s]** %s", f.Severity, f.Finding),
+			})
+		}
 	}
-	log.Printf("Review posted successfully!")
+	if len(inlineComments) > 0 {
+		slog.Debug("attaching inline comments", "count", len(inlineComments))
+	}
+
+	// --- Review update strategy ---
+	// 1. POST new review first (gets non-stale approval badge on HEAD)
+	// 2. Then supersede old review with link to the new one
+	// Order matters: post first so we have the new review's URL for the supersede message.
+	var oldReviews []gitea.Review
+	if *reviewerName != "" {
+		existingReviews, err := giteaClient.ListReviews(ctx, owner, repoName, prNumber)
+		if err != nil {
+			slog.Warn("could not list existing reviews", "pr", prNumber, "error", err)
+		} else {
+			if hasSharedToken(existingReviews, sentinel) {
+				slog.Warn("shared token mode: skipping supersede to avoid clobbering sibling review")
+			} else {
+				oldReviews = findAllOwnReviews(existingReviews, sentinel)
+			}
+		}
+	}
+
+	// Self-request as reviewer (ensures we appear in required-reviewer checks)
+	authUser, err := giteaClient.GetAuthenticatedUser(ctx)
+	if err != nil {
+		slog.Warn("could not determine authenticated user for reviewer self-request", "error", err)
+	} else if authUser != "" {
+		if err := giteaClient.RequestReviewer(ctx, owner, repoName, prNumber, authUser); err != nil {
+			slog.Warn("could not self-request as reviewer", "user", authUser, "error", err)
+		} else {
+			slog.Debug("self-requested as reviewer", "user", authUser, "pr", prNumber)
+		}
+	}
+
+	// POST new review
+	slog.Info("posting review", "event", event, "pr", prNumber)
+	posted, err := giteaClient.PostReview(ctx, owner, repoName, prNumber, event, reviewBody, inlineComments)
+	if err != nil {
+		slog.Error("failed to post review", "pr", prNumber, "event", event, "error", err)
+		os.Exit(1)
+	}
+	slog.Info("review posted", "review_id", posted.ID, "user", posted.User.Login, "pr", prNumber)
+
+	// Supersede all old reviews with link to the new one
+	if len(oldReviews) > 0 {
+		newReviewURL := fmt.Sprintf("%s/%s/%s/pulls/%d#pullrequestreview-%d", strings.TrimRight(*giteaURL, "/"), owner, repoName, prNumber, posted.ID)
+		for _, oldReview := range oldReviews {
+			cid, err := giteaClient.GetTimelineReviewCommentIDForReview(ctx, owner, repoName, prNumber, oldReview.ID)
+			if err != nil {
+				slog.Warn("could not find comment ID for old review", "review_id", oldReview.ID, "error", err)
+				continue
+			}
+			supersededBody := buildSupersededBody(oldReview.Body, oldReview.CommitID, newReviewURL, sentinel)
+			if err := giteaClient.EditComment(ctx, owner, repoName, cid, supersededBody); err != nil {
+				slog.Warn("could not mark old review as superseded", "review_id", oldReview.ID, "comment_id", cid, "error", err)
+				continue
+			}
+			slog.Info("marked old review as superseded", "review_id", oldReview.ID, "new_review_id", posted.ID, "pr", prNumber)
+
+			// Resolve old review's inline comments
+			oldComments, err := giteaClient.ListReviewComments(ctx, owner, repoName, prNumber, oldReview.ID)
+			if err != nil {
+				slog.Warn("could not list old review comments for resolution", "review_id", oldReview.ID, "error", err)
+				continue
+			}
+			resolved, failed := 0, 0
+			for _, c := range oldComments {
+				if c.ID == 0 {
+					continue
+				}
+				if err := giteaClient.ResolveComment(ctx, owner, repoName, c.ID); err != nil {
+					slog.Debug("could not resolve inline comment", "comment_id", c.ID, "error", err)
+					failed++
+				} else {
+					resolved++
+				}
+			}
+			if resolved > 0 {
+				slog.Info("resolved old inline comments", "review_id", oldReview.ID, "count", resolved, "pr", prNumber)
+			}
+			if failed > 0 {
+				slog.Warn("some inline comments could not be resolved", "review_id", oldReview.ID, "failed", failed, "pr", prNumber)
+			}
+		}
+	}
+
 }
 
 // fetchFileContext fetches the full content of modified files from the PR branch.
@@ -187,7 +452,7 @@ func fetchFileContext(ctx context.Context, client *gitea.Client, owner, repo, re
 		}
 		content, err := client.GetFileContentRef(ctx, owner, repo, f.Filename, ref)
 		if err != nil {
-			log.Printf("Warning: could not fetch %s: %v", f.Filename, err)
+			slog.Warn("could not fetch file content", "file", f.Filename, "error", err)
 			continue
 		}
 		sb.WriteString(fmt.Sprintf("--- %s ---\n", f.Filename))
@@ -218,7 +483,7 @@ func fetchPatterns(ctx context.Context, client *gitea.Client, patternsRepo, patt
 		}
 		parts := strings.SplitN(repoRef, "/", 2)
 		if len(parts) != 2 {
-			log.Printf("Warning: invalid patterns-repo format %q, expected owner/name", repoRef)
+			slog.Warn("invalid patterns-repo format", "repo", repoRef, "expected", "owner/name")
 			continue
 		}
 		owner, repo := parts[0], parts[1]
@@ -231,16 +496,16 @@ func fetchPatterns(ctx context.Context, client *gitea.Client, patternsRepo, patt
 
 			files, err := client.GetAllFilesInPath(ctx, owner, repo, path)
 			if err != nil {
-				log.Printf("Warning: could not fetch %s from %s: %v", path, repoRef, err)
+				slog.Warn("could not fetch patterns", "path", path, "repo", repoRef, "error", err)
 				continue
 			}
 
-			for filepath, content := range files {
+			for filePath, content := range files {
 				// Only include markdown and text files as patterns
-				if !isPatternFile(filepath) {
+				if !isPatternFile(filePath) {
 					continue
 				}
-				sb.WriteString(fmt.Sprintf("### %s/%s\n\n%s\n\n", repoRef, filepath, content))
+				sb.WriteString(fmt.Sprintf("### %s/%s\n\n%s\n\n", repoRef, filePath, content))
 			}
 		}
 	}
@@ -306,3 +571,123 @@ func envOrDefaultInt(key string, defaultVal int) int {
 	}
 	return defaultVal
 }
+
+func envOrDefaultBool(key string, defaultVal bool) bool {
+	v := strings.TrimSpace(strings.ToLower(os.Getenv(key)))
+	if v == "" {
+		return defaultVal
+	}
+	return v == "true" || v == "1" || v == "yes"
+}
+
+// validateReviewerName checks that the name contains only safe characters
+// for embedding in an HTML comment sentinel ([a-zA-Z0-9_-]).
+func validateReviewerName(name string) error {
+	if name == "" {
+		return nil
+	}
+	for _, ch := range name {
+		if !((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9') || ch == '-' || ch == '_') {
+			return fmt.Errorf("reviewer-name must contain only [a-zA-Z0-9_-] (got %q)", name)
+		}
+	}
+	return nil
+}
+
+// buildSupersededBody creates the body for a superseded review: struck-through banner
+// with collapsed original content and the commit it was evaluated against.
+func buildSupersededBody(originalBody, commitSHA, newReviewURL, sentinel string) string {
+	shortSHA := commitSHA
+	if len(shortSHA) > 8 {
+		shortSHA = shortSHA[:8]
+	}
+	var sb strings.Builder
+	sb.WriteString("~~Original review~~\n\n")
+	sb.WriteString("**Superseded** \u2014 [see current review](")
+	sb.WriteString(newReviewURL)
+	sb.WriteString(") for up-to-date findings.\n\n")
+	if shortSHA != "" {
+		sb.WriteString("<details><summary>Previous findings (commit ")
+		sb.WriteString(shortSHA)
+		sb.WriteString(")</summary>\n\n")
+	} else {
+		sb.WriteString("<details><summary>Previous findings</summary>\n\n")
+	}
+	sb.WriteString(originalBody)
+	sb.WriteString("\n\n</details>\n\n")
+	sb.WriteString(sentinel)
+	return sb.String()
+}
+
+// hasSharedToken detects if another review-bot role posted under the same
+// Gitea user. This indicates misconfiguration where two roles share a token
+// instead of having separate Gitea accounts. Returns true if shared token
+// detected (caller should skip update-in-place logic to avoid clobbering).
+func hasSharedToken(reviews []gitea.Review, ownSentinel string) bool {
+	ownLogin := ""
+	for _, r := range reviews {
+		if strings.Contains(r.Body, ownSentinel) {
+			ownLogin = r.User.Login
+			break
+		}
+	}
+	if ownLogin == "" {
+		return false
+	}
+	for _, r := range reviews {
+		if r.User.Login == ownLogin && strings.Contains(r.Body, "<!-- review-bot:") && !strings.Contains(r.Body, ownSentinel) {
+			slog.Warn("shared token detected — another review-bot role is using the same Gitea user",
+				"sibling_role", extractSentinelName(r.Body), "user", ownLogin)
+			return true
+		}
+	}
+	return false
+}
+
+// extractSentinelName pulls the reviewer name from a sentinel comment.
+func extractSentinelName(body string) string {
+	const prefix = "<!-- review-bot:"
+	const suffix = " -->"
+	idx := strings.Index(body, prefix)
+	if idx < 0 {
+		return "unknown"
+	}
+	rest := body[idx+len(prefix):]
+	end := strings.Index(rest, suffix)
+	if end < 0 {
+		return "unknown"
+	}
+	return rest[:end]
+}
+
+// findOwnReview locates the most recent non-superseded review matching the sentinel.
+func findOwnReview(reviews []gitea.Review, sentinel string) *gitea.Review {
+	var best *gitea.Review
+	for i := range reviews {
+		if !strings.Contains(reviews[i].Body, sentinel) {
+			continue
+		}
+		if strings.Contains(reviews[i].Body, "~~Original review~~") {
+			continue
+		}
+		if best == nil || reviews[i].ID > best.ID {
+			best = &reviews[i]
+		}
+	}
+	return best
+}
+
+// findAllOwnReviews returns all non-superseded reviews matching the sentinel.
+func findAllOwnReviews(reviews []gitea.Review, sentinel string) []gitea.Review {
+	var result []gitea.Review
+	for i := range reviews {
+		if !strings.Contains(reviews[i].Body, sentinel) {
+			continue
+		}
+		if strings.Contains(reviews[i].Body, "~~Original review~~") {
+			continue
+		}
+		result = append(result, reviews[i])
+	}
+	return result
+}

cmd/review-bot/main_test.go

@@ -0,0 +1,864 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"log/slog"
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+
+	"gitea.weiker.me/rodin/review-bot/gitea"
+)
+
+func TestValidateReviewerName(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		wantErr bool
+	}{
+		{"valid simple", "sonnet", false},
+		{"valid with dash", "code-review", false},
+		{"valid with underscore", "my_bot", false},
+		{"valid alphanumeric", "bot123", false},
+		{"valid uppercase", "MyBot", false},
+		{"empty is valid", "", false},
+		{"invalid html close", "foo-->", true},
+		{"invalid space", "my bot", true},
+		{"invalid dot", "my.bot", true},
+		{"invalid slash", "my/bot", true},
+		{"invalid angle", "bot<script>", true},
+		{"invalid colon", "bot:name", true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := validateReviewerName(tc.input)
+			if tc.wantErr && err == nil {
+				t.Errorf("expected error for %q, got nil", tc.input)
+			}
+			if !tc.wantErr && err != nil {
+				t.Errorf("expected no error for %q, got %v", tc.input, err)
+			}
+		})
+	}
+}
+
+func makeReview(id int64, login, state string, stale bool, body string) gitea.Review {
+	r := gitea.Review{
+		ID:    id,
+		Body:  body,
+		State: state,
+		Stale: stale,
+	}
+	r.User.Login = login
+	return r
+}
+
+
+func TestBuildSupersededBody(t *testing.T) {
+	original := "# Review\n\nLooks good.\n\n<!-- review-bot:sonnet -->"
+	sentinel := "<!-- review-bot:sonnet -->"
+	newURL := "https://gitea.example.com/owner/repo/pulls/1#pullrequestreview-99"
+
+	result := buildSupersededBody(original, "abcdef1234567890", newURL, sentinel)
+
+	// Should contain the struck-through banner
+	if !strings.Contains(result, "~~Original review~~") {
+		t.Error("missing struck-through banner")
+	}
+	// Should contain superseded notice with link
+	if !strings.Contains(result, "**Superseded**") {
+		t.Error("missing superseded notice")
+	}
+	if !strings.Contains(result, "[see current review]("+newURL+")") {
+		t.Error("missing link to new review")
+	}
+	// Should contain collapsed original
+	if !strings.Contains(result, "<details>") {
+		t.Error("missing details/collapse")
+	}
+	// Should contain short commit SHA
+	if !strings.Contains(result, "abcdef12") {
+		t.Error("missing short SHA")
+	}
+	// Should NOT contain full SHA
+	if strings.Contains(result, "abcdef1234567890") {
+		t.Error("should truncate SHA to 8 chars")
+	}
+	// Should contain the original body inside details
+	if !strings.Contains(result, original) {
+		t.Error("original body not preserved in collapsed section")
+	}
+	// Should end with sentinel
+	if !strings.Contains(result, sentinel) {
+		t.Error("missing sentinel")
+	}
+}
+
+func TestBuildSupersededBodyShortSHA(t *testing.T) {
+	// Short SHA should pass through without panic
+	result := buildSupersededBody("body", "abc", "https://example.com/review", "<!-- review-bot:x -->")
+	if !strings.Contains(result, "abc") {
+		t.Error("short SHA not preserved")
+	}
+}
+
+func TestFindOwnReview(t *testing.T) {
+	tests := []struct {
+		name     string
+		reviews  []gitea.Review
+		sentinel string
+		wantID   int64
+		wantNil  bool
+	}{
+		{
+			name:     "no reviews",
+			reviews:  nil,
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantNil:  true,
+		},
+		{
+			name: "found by sentinel",
+			reviews: []gitea.Review{
+				makeReview(42, "bot", "APPROVED", false, "review body\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantID:   42,
+		},
+		{
+			name: "wrong sentinel",
+			reviews: []gitea.Review{
+				makeReview(42, "bot", "APPROVED", false, "body\n<!-- review-bot:gpt -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantNil:  true,
+		},
+		{
+			name: "multiple reviews, returns first match",
+			reviews: []gitea.Review{
+				makeReview(10, "bot", "APPROVED", false, "old\n<!-- review-bot:gpt -->"),
+				makeReview(20, "bot", "APPROVED", false, "new\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantID:   20,
+		},
+		{
+			name: "skips superseded review",
+			reviews: []gitea.Review{
+				makeReview(10, "bot", "APPROVED", false, "~~Original review~~\n\n**Superseded**\n<!-- review-bot:sonnet -->"),
+				makeReview(20, "bot", "APPROVED", false, "fresh review\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantID:   20,
+		},
+		{
+			name: "only superseded reviews exist",
+			reviews: []gitea.Review{
+				makeReview(10, "bot", "APPROVED", false, "~~Original review~~\n\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantNil:  true,
+		},
+		{
+			name: "picks highest ID among matches",
+			reviews: []gitea.Review{
+				makeReview(50, "bot", "APPROVED", false, "v1\n<!-- review-bot:sonnet -->"),
+				makeReview(30, "bot", "APPROVED", false, "v0\n<!-- review-bot:sonnet -->"),
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			wantID:   50,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := findOwnReview(tc.reviews, tc.sentinel)
+			if tc.wantNil {
+				if got != nil {
+					t.Errorf("findOwnReview() = %v, want nil", got)
+				}
+			} else {
+				if got == nil {
+					t.Fatal("findOwnReview() = nil, want non-nil")
+				}
+				if got.ID != tc.wantID {
+					t.Errorf("findOwnReview().ID = %d, want %d", got.ID, tc.wantID)
+				}
+			}
+		})
+	}
+}
+
+func TestHasSharedToken(t *testing.T) {
+	tests := []struct {
+		name     string
+		reviews  []gitea.Review
+		sentinel string
+		want     bool
+	}{
+		{
+			name:     "no reviews",
+			reviews:  nil,
+			sentinel: "<!-- review-bot:sonnet -->",
+			want:     false,
+		},
+		{
+			name: "no own review yet - cannot detect",
+			reviews: []gitea.Review{
+				{ID: 1, User: struct{ Login string `json:"login"` }{Login: "other"}, Body: "<!-- review-bot:gpt --> body"},
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			want:     false,
+		},
+		{
+			name: "separate users - no shared token",
+			reviews: []gitea.Review{
+				{ID: 1, User: struct{ Login string `json:"login"` }{Login: "sonnet-review-bot"}, Body: "<!-- review-bot:sonnet --> body"},
+				{ID: 2, User: struct{ Login string `json:"login"` }{Login: "security-review-bot"}, Body: "<!-- review-bot:security --> body"},
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			want:     false,
+		},
+		{
+			name: "shared token detected - same user different sentinels",
+			reviews: []gitea.Review{
+				{ID: 1, User: struct{ Login string `json:"login"` }{Login: "sonnet-review-bot"}, Body: "<!-- review-bot:sonnet --> body"},
+				{ID: 2, User: struct{ Login string `json:"login"` }{Login: "sonnet-review-bot"}, Body: "<!-- review-bot:security --> body"},
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			want:     true,
+		},
+		{
+			name: "three roles same user",
+			reviews: []gitea.Review{
+				{ID: 1, User: struct{ Login string `json:"login"` }{Login: "bot"}, Body: "<!-- review-bot:sonnet --> body"},
+				{ID: 2, User: struct{ Login string `json:"login"` }{Login: "bot"}, Body: "<!-- review-bot:security --> body"},
+				{ID: 3, User: struct{ Login string `json:"login"` }{Login: "bot"}, Body: "<!-- review-bot:gpt --> body"},
+			},
+			sentinel: "<!-- review-bot:sonnet -->",
+			want:     true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := hasSharedToken(tc.reviews, tc.sentinel)
+			if got != tc.want {
+				t.Errorf("hasSharedToken() = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestExtractSentinelName(t *testing.T) {
+	tests := []struct {
+		body string
+		want string
+	}{
+		{"<!-- review-bot:sonnet --> rest", "sonnet"},
+		{"<!-- review-bot:security --> rest", "security"},
+		{"no sentinel here", "unknown"},
+		{"<!-- review-bot:gpt-review --> rest", "gpt-review"},
+	}
+
+	for _, tc := range tests {
+		got := extractSentinelName(tc.body)
+		if got != tc.want {
+			t.Errorf("extractSentinelName(%q) = %q, want %q", tc.body, got, tc.want)
+		}
+	}
+}
+
+func TestSetupLogger_JSONFormat(t *testing.T) {
+	// Capture output by creating a logger manually with the same logic
+	var buf bytes.Buffer
+	opts := &slog.HandlerOptions{Level: slog.LevelInfo}
+	handler := slog.NewJSONHandler(&buf, opts)
+	logger := slog.New(handler)
+
+	logger.Info("test message", "key", "value")
+
+	output := buf.String()
+	if !strings.Contains(output, `"msg":"test message"`) {
+		t.Errorf("expected JSON msg field, got: %s", output)
+	}
+	if !strings.Contains(output, `"key":"value"`) {
+		t.Errorf("expected JSON key field, got: %s", output)
+	}
+	if !strings.Contains(output, `"level":"INFO"`) {
+		t.Errorf("expected JSON level field, got: %s", output)
+	}
+}
+
+func TestSetupLogger_TextFormat(t *testing.T) {
+	var buf bytes.Buffer
+	opts := &slog.HandlerOptions{Level: slog.LevelInfo}
+	handler := slog.NewTextHandler(&buf, opts)
+	logger := slog.New(handler)
+
+	logger.Info("test message", "key", "value")
+
+	output := buf.String()
+	if !strings.Contains(output, "msg=\"test message\"") && !strings.Contains(output, "msg=test") {
+		t.Errorf("expected text msg field, got: %s", output)
+	}
+	if !strings.Contains(output, "key=value") {
+		t.Errorf("expected text key field, got: %s", output)
+	}
+}
+
+func TestSetupLogger_LevelFiltering(t *testing.T) {
+	tests := []struct {
+		name      string
+		verbosity string
+		logLevel  slog.Level
+		expected  bool // should the message appear
+	}{
+		{"info logger shows info", "info", slog.LevelInfo, true},
+		{"info logger hides debug", "info", slog.LevelDebug, false},
+		{"debug logger shows debug", "debug", slog.LevelDebug, true},
+		{"warn logger hides info", "warn", slog.LevelInfo, false},
+		{"warn logger shows warn", "warn", slog.LevelWarn, true},
+		{"error logger hides warn", "error", slog.LevelWarn, false},
+		{"error logger shows error", "error", slog.LevelError, true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			var level slog.Level
+			switch tc.verbosity {
+			case "debug":
+				level = slog.LevelDebug
+			case "info":
+				level = slog.LevelInfo
+			case "warn":
+				level = slog.LevelWarn
+			case "error":
+				level = slog.LevelError
+			}
+
+			var buf bytes.Buffer
+			opts := &slog.HandlerOptions{Level: level}
+			handler := slog.NewTextHandler(&buf, opts)
+			logger := slog.New(handler)
+
+			logger.Log(nil, tc.logLevel, "test")
+
+			hasOutput := buf.Len() > 0
+			if hasOutput != tc.expected {
+				t.Errorf("verbosity=%s, logLevel=%s: got output=%v, want %v",
+					tc.verbosity, tc.logLevel, hasOutput, tc.expected)
+			}
+		})
+	}
+}
+
+func TestSetupLogger_Integration(t *testing.T) {
+	// Test that setupLogger doesn't panic for valid inputs
+	setupLogger("text", "info")
+	setupLogger("json", "debug")
+	setupLogger("text", "warn")
+	setupLogger("json", "error")
+	setupLogger("text", "unknown") // should default to info
+	setupLogger("invalid", "info") // should default to text
+}
+
+func TestIsPatternFile(t *testing.T) {
+	tests := []struct {
+		path string
+		want bool
+	}{
+		{"README.md", true},
+		{"docs/GUIDE.MD", true},
+		{"config.yml", true},
+		{"config.yaml", true},
+		{"notes.txt", true},
+		{"NOTES.TXT", true},
+		{"main.go", false},
+		{"lib.rs", false},
+		{"index.js", false},
+		{"Makefile", false},
+		{"", false},
+		{"doc.pdf", false},
+		{"patterns.Yml", true},
+		{"deep/path/file.yaml", true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.path, func(t *testing.T) {
+			got := isPatternFile(tc.path)
+			if got != tc.want {
+				t.Errorf("isPatternFile(%q) = %v, want %v", tc.path, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestEvaluateCIStatus(t *testing.T) {
+	tests := []struct {
+		name       string
+		statuses   []gitea.CommitStatus
+		wantPassed bool
+		wantSubstr string
+	}{
+		{
+			name:       "empty statuses",
+			statuses:   nil,
+			wantPassed: true,
+			wantSubstr: "no CI statuses",
+		},
+		{
+			name: "all success",
+			statuses: []gitea.CommitStatus{
+				{Status: "success", Context: "ci/build", Description: "Build passed"},
+				{Status: "success", Context: "ci/test", Description: "Tests passed"},
+			},
+			wantPassed: true,
+			wantSubstr: "all checks passed",
+		},
+		{
+			name: "one failure",
+			statuses: []gitea.CommitStatus{
+				{Status: "success", Context: "ci/build", Description: "Build passed"},
+				{Status: "failure", Context: "ci/test", Description: "Tests failed"},
+			},
+			wantPassed: false,
+			wantSubstr: "ci/test",
+		},
+		{
+			name: "error status",
+			statuses: []gitea.CommitStatus{
+				{Status: "error", Context: "ci/lint", Description: "Lint error"},
+			},
+			wantPassed: false,
+			wantSubstr: "ci/lint",
+		},
+		{
+			name: "pending treated as not-failed",
+			statuses: []gitea.CommitStatus{
+				{Status: "pending", Context: "ci/build", Description: "In progress"},
+				{Status: "success", Context: "ci/test", Description: "Tests passed"},
+			},
+			wantPassed: true,
+			wantSubstr: "all checks passed",
+		},
+		{
+			name: "multiple failures",
+			statuses: []gitea.CommitStatus{
+				{Status: "failure", Context: "ci/build", Description: "Build failed"},
+				{Status: "failure", Context: "ci/test", Description: "Tests failed"},
+			},
+			wantPassed: false,
+			wantSubstr: "ci/build",
+		},
+		{
+			name: "mixed with pending and failure",
+			statuses: []gitea.CommitStatus{
+				{Status: "success", Context: "ci/build", Description: "Build passed"},
+				{Status: "pending", Context: "ci/deploy", Description: "Deploying"},
+				{Status: "failure", Context: "ci/test", Description: "Tests failed"},
+			},
+			wantPassed: false,
+			wantSubstr: "ci/test",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			passed, details := evaluateCIStatus(tc.statuses)
+			if passed != tc.wantPassed {
+				t.Errorf("evaluateCIStatus() passed = %v, want %v", passed, tc.wantPassed)
+			}
+			if !strings.Contains(details, tc.wantSubstr) {
+				t.Errorf("evaluateCIStatus() details = %q, want substring %q", details, tc.wantSubstr)
+			}
+		})
+	}
+}
+
+func TestEnvOrDefault(t *testing.T) {
+	// Test with unset env var
+	os.Unsetenv("TEST_ENV_OR_DEFAULT_UNSET")
+	got := envOrDefault("TEST_ENV_OR_DEFAULT_UNSET", "fallback")
+	if got != "fallback" {
+		t.Errorf("envOrDefault(unset) = %q, want %q", got, "fallback")
+	}
+
+	// Test with set env var
+	os.Setenv("TEST_ENV_OR_DEFAULT_SET", "custom")
+	defer os.Unsetenv("TEST_ENV_OR_DEFAULT_SET")
+	got = envOrDefault("TEST_ENV_OR_DEFAULT_SET", "fallback")
+	if got != "custom" {
+		t.Errorf("envOrDefault(set) = %q, want %q", got, "custom")
+	}
+
+	// Test with empty env var (should return default)
+	os.Setenv("TEST_ENV_OR_DEFAULT_EMPTY", "")
+	defer os.Unsetenv("TEST_ENV_OR_DEFAULT_EMPTY")
+	got = envOrDefault("TEST_ENV_OR_DEFAULT_EMPTY", "fallback")
+	if got != "fallback" {
+		t.Errorf("envOrDefault(empty) = %q, want %q", got, "fallback")
+	}
+}
+
+func TestEnvOrDefaultFloat(t *testing.T) {
+	// Test with unset env var
+	os.Unsetenv("TEST_ENV_FLOAT_UNSET")
+	got := envOrDefaultFloat("TEST_ENV_FLOAT_UNSET", 1.5)
+	if got != 1.5 {
+		t.Errorf("envOrDefaultFloat(unset) = %f, want %f", got, 1.5)
+	}
+
+	// Test with valid float
+	os.Setenv("TEST_ENV_FLOAT_SET", "2.7")
+	defer os.Unsetenv("TEST_ENV_FLOAT_SET")
+	got = envOrDefaultFloat("TEST_ENV_FLOAT_SET", 1.5)
+	if got != 2.7 {
+		t.Errorf("envOrDefaultFloat(set) = %f, want %f", got, 2.7)
+	}
+
+	// Test with invalid float (should return default)
+	os.Setenv("TEST_ENV_FLOAT_INVALID", "not-a-number")
+	defer os.Unsetenv("TEST_ENV_FLOAT_INVALID")
+	got = envOrDefaultFloat("TEST_ENV_FLOAT_INVALID", 3.14)
+	if got != 3.14 {
+		t.Errorf("envOrDefaultFloat(invalid) = %f, want %f", got, 3.14)
+	}
+
+	// Test with empty string (should return default)
+	os.Setenv("TEST_ENV_FLOAT_EMPTY", "")
+	defer os.Unsetenv("TEST_ENV_FLOAT_EMPTY")
+	got = envOrDefaultFloat("TEST_ENV_FLOAT_EMPTY", 0.5)
+	if got != 0.5 {
+		t.Errorf("envOrDefaultFloat(empty) = %f, want %f", got, 0.5)
+	}
+}
+
+func TestEnvOrDefaultInt(t *testing.T) {
+	// Test with unset env var
+	os.Unsetenv("TEST_ENV_INT_UNSET")
+	got := envOrDefaultInt("TEST_ENV_INT_UNSET", 42)
+	if got != 42 {
+		t.Errorf("envOrDefaultInt(unset) = %d, want %d", got, 42)
+	}
+
+	// Test with valid int
+	os.Setenv("TEST_ENV_INT_SET", "100")
+	defer os.Unsetenv("TEST_ENV_INT_SET")
+	got = envOrDefaultInt("TEST_ENV_INT_SET", 42)
+	if got != 100 {
+		t.Errorf("envOrDefaultInt(set) = %d, want %d", got, 100)
+	}
+
+	// Test with invalid int (should return default)
+	os.Setenv("TEST_ENV_INT_INVALID", "abc")
+	defer os.Unsetenv("TEST_ENV_INT_INVALID")
+	got = envOrDefaultInt("TEST_ENV_INT_INVALID", 42)
+	if got != 42 {
+		t.Errorf("envOrDefaultInt(invalid) = %d, want %d", got, 42)
+	}
+
+	// Test with empty string (should return default)
+	os.Setenv("TEST_ENV_INT_EMPTY", "")
+	defer os.Unsetenv("TEST_ENV_INT_EMPTY")
+	got = envOrDefaultInt("TEST_ENV_INT_EMPTY", 99)
+	if got != 99 {
+		t.Errorf("envOrDefaultInt(empty) = %d, want %d", got, 99)
+	}
+
+	// Test with negative int
+	os.Setenv("TEST_ENV_INT_NEG", "-5")
+	defer os.Unsetenv("TEST_ENV_INT_NEG")
+	got = envOrDefaultInt("TEST_ENV_INT_NEG", 42)
+	if got != -5 {
+		t.Errorf("envOrDefaultInt(negative) = %d, want %d", got, -5)
+	}
+}
+
+func TestEnvOrDefaultBool(t *testing.T) {
+	tests := []struct {
+		name       string
+		envVal     string
+		setEnv     bool
+		defaultVal bool
+		want       bool
+	}{
+		{"unset returns default true", "", false, true, true},
+		{"unset returns default false", "", false, false, false},
+		{"true", "true", true, false, true},
+		{"TRUE", "TRUE", true, false, true},
+		{"True", "True", true, false, true},
+		{"1", "1", true, false, true},
+		{"yes", "yes", true, false, true},
+		{"YES", "YES", true, false, true},
+		{"false", "false", true, true, false},
+		{"0", "0", true, true, false},
+		{"no", "no", true, true, false},
+		{"random string", "random", true, true, false},
+		{"empty string returns default", "", true, true, true},
+		{"whitespace true", "  true  ", true, false, true},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			envKey := "TEST_ENV_BOOL_" + strings.ReplaceAll(tc.name, " ", "_")
+			if tc.setEnv {
+				os.Setenv(envKey, tc.envVal)
+				defer os.Unsetenv(envKey)
+			} else {
+				os.Unsetenv(envKey)
+			}
+			got := envOrDefaultBool(envKey, tc.defaultVal)
+			if got != tc.want {
+				t.Errorf("envOrDefaultBool(%q, %v) = %v, want %v", tc.envVal, tc.defaultVal, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestExtractSentinelName_EdgeCases(t *testing.T) {
+	tests := []struct {
+		body string
+		want string
+	}{
+		{"<!-- review-bot:sonnet --> rest", "sonnet"},
+		{"<!-- review-bot:gpt-review --> rest", "gpt-review"},
+		{"no sentinel here", "unknown"},
+		{"<!-- review-bot:", "unknown"},       // prefix but no suffix
+		{"prefix <!-- review-bot:abc --> end", "abc"}, // embedded in text
+	}
+
+	for _, tc := range tests {
+		got := extractSentinelName(tc.body)
+		if got != tc.want {
+			t.Errorf("extractSentinelName(%q) = %q, want %q", tc.body, got, tc.want)
+		}
+	}
+}
+
+// TestMainSubprocess runs main() as a subprocess using the test binary itself.
+// This allows coverage to be captured for main() code paths.
+func TestMainSubprocess_Version(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		// Reset flags for main()
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot", "--version"}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_Version")
+	cmd.Env = append(os.Environ(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("--version subprocess failed: %v\n%s", err, out)
+	}
+	if !strings.Contains(string(out), "review-bot") {
+		t.Errorf("--version output = %q, want to contain 'review-bot'", string(out))
+	}
+}
+
+func TestMainSubprocess_MissingFlags(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		// Reset flags for main()
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot"}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_MissingFlags")
+	cmd.Env = append(cleanEnv(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err == nil {
+		t.Fatal("expected non-zero exit with no flags, got success")
+	}
+	if !strings.Contains(string(out), "missing required") {
+		t.Errorf("expected error about missing flags, got: %s", out)
+	}
+}
+
+func TestMainSubprocess_InvalidReviewerName(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot",
+			"--gitea-url", "http://localhost",
+			"--repo", "owner/repo",
+			"--pr", "1",
+			"--reviewer-name", "invalid name",
+			"--reviewer-token", "tok",
+			"--llm-base-url", "http://localhost",
+			"--llm-api-key", "key",
+			"--llm-model", "model",
+		}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidReviewerName")
+	cmd.Env = append(cleanEnv(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err == nil {
+		t.Fatal("expected non-zero exit with invalid reviewer-name, got success")
+	}
+	if !strings.Contains(string(out), "invalid reviewer name") {
+		t.Errorf("expected error about invalid reviewer name, got: %s", out)
+	}
+}
+
+func TestMainSubprocess_InvalidRepo(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot",
+			"--gitea-url", "http://localhost",
+			"--repo", "invalidrepo",
+			"--pr", "1",
+			"--reviewer-token", "tok",
+			"--llm-base-url", "http://localhost",
+			"--llm-api-key", "key",
+			"--llm-model", "model",
+		}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidRepo")
+	cmd.Env = append(cleanEnv(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err == nil {
+		t.Fatal("expected non-zero exit with invalid repo format")
+	}
+	if !strings.Contains(string(out), "invalid repo format") {
+		t.Errorf("expected error about invalid repo, got: %s", out)
+	}
+}
+
+func TestMainSubprocess_InvalidPRNumber(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot",
+			"--gitea-url", "http://localhost",
+			"--repo", "owner/repo",
+			"--pr", "notanumber",
+			"--reviewer-token", "tok",
+			"--llm-base-url", "http://localhost",
+			"--llm-api-key", "key",
+			"--llm-model", "model",
+		}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidPRNumber")
+	cmd.Env = append(cleanEnv(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err == nil {
+		t.Fatal("expected non-zero exit with invalid PR number")
+	}
+	if !strings.Contains(string(out), "invalid PR number") {
+		t.Errorf("expected error about invalid PR number, got: %s", out)
+	}
+}
+
+func TestMainSubprocess_InvalidTemperature(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot",
+			"--gitea-url", "http://localhost",
+			"--repo", "owner/repo",
+			"--pr", "1",
+			"--reviewer-token", "tok",
+			"--llm-base-url", "http://localhost",
+			"--llm-api-key", "key",
+			"--llm-model", "model",
+			"--llm-temperature", "5.0",
+		}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidTemperature")
+	cmd.Env = append(cleanEnv(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err == nil {
+		t.Fatal("expected non-zero exit with invalid temperature")
+	}
+	if !strings.Contains(string(out), "invalid LLM temperature") {
+		t.Errorf("expected error about invalid temperature, got: %s", out)
+	}
+}
+
+func TestMainSubprocess_InvalidProvider(t *testing.T) {
+	if os.Getenv("TEST_SUBPROCESS_MAIN") == "1" {
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ExitOnError)
+		os.Args = []string{"review-bot",
+			"--gitea-url", "http://localhost",
+			"--repo", "owner/repo",
+			"--pr", "1",
+			"--reviewer-token", "tok",
+			"--llm-base-url", "http://localhost",
+			"--llm-api-key", "key",
+			"--llm-model", "model",
+			"--llm-provider", "invalid-provider",
+		}
+		main()
+		return
+	}
+
+	cmd := exec.Command(os.Args[0], "-test.run=TestMainSubprocess_InvalidProvider")
+	cmd.Env = append(cleanEnv(), "TEST_SUBPROCESS_MAIN=1")
+	out, err := cmd.CombinedOutput()
+	if err == nil {
+		t.Fatal("expected non-zero exit with invalid provider")
+	}
+	if !strings.Contains(string(out), "invalid LLM provider") {
+		t.Errorf("expected error about invalid provider, got: %s", out)
+	}
+}
+
+// cleanEnv returns environ without any GITEA/LLM/REVIEWER env vars that would
+// interfere with testing missing-flag scenarios.
+func cleanEnv() []string {
+	var env []string
+	for _, e := range os.Environ() {
+		key := strings.SplitN(e, "=", 2)[0]
+		switch {
+		case strings.HasPrefix(key, "GITEA_"),
+			strings.HasPrefix(key, "LLM_"),
+			strings.HasPrefix(key, "REVIEWER_"),
+			strings.HasPrefix(key, "PR_"),
+			strings.HasPrefix(key, "LOG_"),
+			strings.HasPrefix(key, "CONVENTIONS_"),
+			strings.HasPrefix(key, "SYSTEM_PROMPT_"),
+			strings.HasPrefix(key, "PATTERNS_"),
+			strings.HasPrefix(key, "UPDATE_"):
+			continue
+		default:
+			env = append(env, e)
+		}
+	}
+	return env
+}
+
+func TestFindAllOwnReviews(t *testing.T) {
+	reviews := []gitea.Review{
+		{ID: 1, Body: "<!-- review-bot:sonnet -->\nfirst review"},
+		{ID: 2, Body: "<!-- review-bot:gpt -->\nother bot"},
+		{ID: 3, Body: "<!-- review-bot:sonnet -->\nsecond review"},
+		{ID: 4, Body: "~~Original review~~\n<!-- review-bot:sonnet -->\nsuperseded"},
+		{ID: 5, Body: "<!-- review-bot:sonnet -->\nthird review"},
+	}
+
+	got := findAllOwnReviews(reviews, "<!-- review-bot:sonnet -->")
+	if len(got) != 3 {
+		t.Fatalf("findAllOwnReviews() returned %d, want 3", len(got))
+	}
+	wantIDs := []int64{1, 3, 5}
+	for i, r := range got {
+		if r.ID != wantIDs[i] {
+			t.Errorf("got[%d].ID = %d, want %d", i, r.ID, wantIDs[i])
+		}
+	}
+}

docs/REVIEW_STRATEGY.md

@@ -0,0 +1,97 @@
+# Review Update Strategy
+
+review-bot uses an **edit-in-place** strategy for updating reviews. Reviews are never deleted — this preserves conversation threads on inline comments.
+
+## State Transition Diagram
+
+```mermaid
+stateDiagram-v2
+    [*] --> NoExistingReview: First run
+
+    NoExistingReview --> POST_Review: Generate findings + event
+    POST_Review --> PostEscalationCheck: event == APPROVED?
+
+    PostEscalationCheck --> Done: No sibling blocks
+    PostEscalationCheck --> Supersede_And_Repost: Sibling has REQUEST_CHANGES
+    Supersede_And_Repost --> Done: Posted as REQUEST_CHANGES
+
+    [*] --> ExistingReviewFound: Subsequent run (sentinel match)
+
+    ExistingReviewFound --> CheckEscalation: Determine final event
+    CheckEscalation --> CompareState: Apply worst-wins if needed
+
+    CompareState --> SameState: existing.state == new event
+    CompareState --> StateChange: existing.state != new event
+
+    SameState --> Skip: Body unchanged
+    SameState --> PatchBody: Body changed → PATCH in place
+
+    StateChange --> Escalate: APPROVED → REQUEST_CHANGES
+    StateChange --> Downgrade: REQUEST_CHANGES → APPROVED
+
+    Escalate --> Supersede: PATCH old body → "Superseded"
+    Supersede --> POST_New_RC: POST new REQUEST_CHANGES
+
+    Downgrade --> POST_New_Approve: POST new APPROVED (old stays intact)
+
+    Skip --> Done
+    PatchBody --> Done
+    POST_New_RC --> Done
+    POST_New_Approve --> Done
+```
+
+## Rules
+
+| Scenario | Action | Reason |
+|----------|--------|--------|
+| No existing review | POST new | First run |
+| Same state, same body | Skip | Nothing changed — preserve threads |
+| Same state, body changed | PATCH body | Update findings without losing threads |
+| APPROVED → REQUEST_CHANGES | Supersede old + POST new | Can always escalate; old APPROVED is no longer valid |
+| REQUEST_CHANGES → APPROVED | POST new APPROVED | Can't edit state; old REQUEST_CHANGES stays as historical record |
+| Sibling has REQUEST_CHANGES (worst-wins) | Escalate to REQUEST_CHANGES | PR must stay blocked if ANY reviewer blocks |
+
+## Key Constraints
+
+1. **Review state is immutable after POST** — Gitea has no API to change APPROVED ↔ REQUEST_CHANGES
+2. **Never delete reviews** — Deleting cascades to inline comments and reply threads
+3. **"Last review per user" wins** — Gitea uses the most recent review from a user for merge decisions
+4. **REQUEST_CHANGES reviews are never touched** — Their inline comments and threads are preserved as historical record
+5. **APPROVED reviews can be superseded** — When escalation is needed, mark old as superseded and POST new
+
+## Worst-Wins (Shared Token)
+
+When multiple reviewer roles share a token (e.g., `sonnet` and `security` both use `sonnet-review-bot`):
+
+```
+CI Matrix Run:
+  sonnet  → REQUEST_CHANGES (findings)
+  security → APPROVED (no security issues)
+                ↓
+  security sees sibling REQUEST_CHANGES
+                ↓
+  security escalates → REQUEST_CHANGES
+                ↓
+  PR stays blocked ✓
+```
+
+The **first-run case** (no existing review to read login from) uses a post-posting fallback:
+POST APPROVED → check siblings → if blocked, supersede own APPROVED → re-POST as REQUEST_CHANGES.
+
+## Edit Mechanism
+
+Reviews are edited via `PATCH /repos/{owner}/{repo}/issues/comments/{id}`:
+
+- **Review body**: ID obtained from the timeline API (`/issues/{index}/timeline`, type `"review"`)
+- **Inline comments**: IDs obtained from `/pulls/{index}/reviews/{id}/comments`
+- **Both are editable** by the token that created them
+- **ListReviews always returns the original body** (reads from review table, not comment table) — sentinel matching works regardless of edits
+
+## Inline Comments Lifecycle
+
+| Event | Inline comments behavior |
+|-------|--------------------------|
+| First POST | Created on specific diff lines |
+| PATCH body (same state) | Unchanged — still current findings |
+| Supersede (state change) | Old inline comments stay (readable but on outdated code) |
+| New POST after supersede | Fresh inline comments on current diff |

gitea/client.go

@@ -1,17 +1,44 @@
+// Package gitea provides a client for the Gitea API.
+// It supports pull request operations, file content retrieval,
+// and review submission.
 package gitea
 
 import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
-	"log"
+	"log/slog"
 	"net/http"
+	"net/url"
 	"strings"
 	"time"
 )
 
+// APIError represents an HTTP error response from the Gitea API.
+// It carries the status code so callers can distinguish between
+// different failure modes (e.g. 404 vs 500).
+type APIError struct {
+	StatusCode int
+	Body       string
+}
+
+func (e *APIError) Error() string {
+	body := e.Body
+	if len(body) > 200 {
+		body = body[:200] + "...(truncated)"
+	}
+	return fmt.Sprintf("HTTP %d: %s", e.StatusCode, body)
+}
+
+// IsNotFound reports whether an error is an API 404 response.
+func IsNotFound(err error) bool {
+	var apiErr *APIError
+	return errors.As(err, &apiErr) && apiErr.StatusCode == http.StatusNotFound
+}
+
 // Client interacts with the Gitea API.
 // A Client is safe for concurrent use by multiple goroutines.
 type Client struct {
@@ -53,10 +80,18 @@ type ChangedFile struct {
 	Status   string `json:"status"`
 }
 
+// ReviewComment represents an inline comment to attach to a review.
+type ReviewComment struct {
+	ID          int64  `json:"id,omitempty"`
+	Path        string `json:"path"`
+	NewPosition int64  `json:"new_position"`
+	Body        string `json:"body"`
+}
+
 // GetPullRequest fetches PR metadata.
 func (c *Client) GetPullRequest(ctx context.Context, owner, repo string, number int) (*PullRequest, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d", c.baseURL, owner, repo, number)
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
-	body, err := c.doGet(ctx, url)
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return nil, fmt.Errorf("fetch PR: %w", err)
 	}
@@ -69,8 +104,8 @@ func (c *Client) GetPullRequest(ctx context.Context, owner, repo string, number
 
 // GetPullRequestDiff fetches the unified diff for a PR.
 func (c *Client) GetPullRequestDiff(ctx context.Context, owner, repo string, number int) (string, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d.diff", c.baseURL, owner, repo, number)
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d.diff", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
-	body, err := c.doGet(ctx, url)
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return "", fmt.Errorf("fetch diff: %w", err)
 	}
@@ -79,8 +114,8 @@ func (c *Client) GetPullRequestDiff(ctx context.Context, owner, repo string, num
 
 // GetPullRequestFiles fetches the list of files changed in a PR.
 func (c *Client) GetPullRequestFiles(ctx context.Context, owner, repo string, number int) ([]ChangedFile, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/files", c.baseURL, owner, repo, number)
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/files", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
-	body, err := c.doGet(ctx, url)
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return nil, fmt.Errorf("fetch PR files: %w", err)
 	}
@@ -93,8 +128,8 @@ func (c *Client) GetPullRequestFiles(ctx context.Context, owner, repo string, nu
 
 // GetCommitStatuses fetches CI statuses for a commit SHA.
 func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string) ([]CommitStatus, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/commits/%s/statuses", c.baseURL, owner, repo, sha)
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/commits/%s/statuses", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), url.PathEscape(sha))
-	body, err := c.doGet(ctx, url)
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return nil, fmt.Errorf("fetch commit statuses: %w", err)
 	}
@@ -107,8 +142,8 @@ func (c *Client) GetCommitStatuses(ctx context.Context, owner, repo, sha string)
 
 // GetFileContent fetches a file from the default branch of a repo.
 func (c *Client) GetFileContent(ctx context.Context, owner, repo, filepath string) (string, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/raw/%s", c.baseURL, owner, repo, filepath)
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/raw/%s", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(filepath))
-	body, err := c.doGet(ctx, url)
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return "", fmt.Errorf("fetch file %s: %w", filepath, err)
 	}
@@ -117,54 +152,66 @@ func (c *Client) GetFileContent(ctx context.Context, owner, repo, filepath strin
 
 // GetFileContentRef fetches a file from a specific ref (branch/tag/sha) in a repo.
 func (c *Client) GetFileContentRef(ctx context.Context, owner, repo, filepath, ref string) (string, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/raw/%s?ref=%s", c.baseURL, owner, repo, filepath, ref)
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/raw/%s?ref=%s", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(filepath), url.QueryEscape(ref))
-	body, err := c.doGet(ctx, url)
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return "", fmt.Errorf("fetch file %s@%s: %w", filepath, ref, err)
 	}
 	return string(body), nil
 }
 
-// PostReview submits a review to a PR.
+// PostReview submits a review to a PR and returns the created review.
 // event should be "APPROVED" or "REQUEST_CHANGES".
-func (c *Client) PostReview(ctx context.Context, owner, repo string, number int, event, body string) error {
+// comments are optional inline comments attached to specific lines.
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews", c.baseURL, owner, repo, number)
+func (c *Client) PostReview(ctx context.Context, owner, repo string, number int, event, body string, comments []ReviewComment) (*Review, error) {
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), number)
 
 	payload := struct {
-		Body  string `json:"body"`
+		Body     string          `json:"body"`
-		Event string `json:"event"`
+		Event    string          `json:"event"`
+		Comments []ReviewComment `json:"comments,omitempty"`
 	}{
-		Body:  body,
+		Body:     body,
-		Event: event,
+		Event:    event,
+		Comments: comments,
 	}
 
 	data, err := json.Marshal(payload)
 	if err != nil {
-		return fmt.Errorf("marshal review payload: %w", err)
+		return nil, fmt.Errorf("marshal review payload: %w", err)
 	}
 
-	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(data))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, reqURL, bytes.NewReader(data))
 	if err != nil {
-		return fmt.Errorf("create review request: %w", err)
+		return nil, fmt.Errorf("create review request: %w", err)
 	}
 	req.Header.Set("Authorization", "token "+c.token)
 	req.Header.Set("Content-Type", "application/json")
 
 	resp, err := c.http.Do(req)
 	if err != nil {
-		return fmt.Errorf("post review: %w", err)
+		return nil, fmt.Errorf("post review: %w", err)
 	}
 	defer resp.Body.Close()
 
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		respBody, _ := io.ReadAll(resp.Body)
-		return fmt.Errorf("post review failed (status %d): %s", resp.StatusCode, string(respBody))
+		return nil, fmt.Errorf("post review failed (status %d): %s", resp.StatusCode, string(respBody))
 	}
-	return nil
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read review response: %w", err)
+	}
+	var review Review
+	if err := json.Unmarshal(respBody, &review); err != nil {
+		return nil, fmt.Errorf("parse review response: %w", err)
+	}
+	return &review, nil
 }
 
-func (c *Client) doGet(ctx context.Context, url string) ([]byte, error) {
+func (c *Client) doGet(ctx context.Context, reqURL string) ([]byte, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -178,11 +225,23 @@ func (c *Client) doGet(ctx context.Context, url string) ([]byte, error) {
 
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		body, _ := io.ReadAll(resp.Body)
-		return nil, fmt.Errorf("HTTP %d: %s", resp.StatusCode, string(body))
+		return nil, &APIError{StatusCode: resp.StatusCode, Body: string(body)}
 	}
 	return io.ReadAll(resp.Body)
 }
 
+// escapePath escapes each segment of a relative file path for use in URLs.
+// Slashes are preserved as path separators; other special characters are escaped.
+// Input should be a relative path (no leading slash). Already-encoded segments
+// will be double-encoded, which is the desired behavior for user-provided paths.
+func escapePath(p string) string {
+	parts := strings.Split(p, "/")
+	for i, part := range parts {
+		parts[i] = url.PathEscape(part)
+	}
+	return strings.Join(parts, "/")
+}
+
 // ContentEntry represents a file or directory entry from the contents API.
 type ContentEntry struct {
 	Name string `json:"name"`
@@ -191,9 +250,15 @@ type ContentEntry struct {
 }
 
 // ListContents lists files and directories at a given path in a repo.
+// Pass an empty path to list the repository root.
 func (c *Client) ListContents(ctx context.Context, owner, repo, path string) ([]ContentEntry, error) {
-	url := fmt.Sprintf("%s/api/v1/repos/%s/%s/contents/%s", c.baseURL, owner, repo, path)
+	var reqURL string
-	body, err := c.doGet(ctx, url)
+	if path == "" {
+		reqURL = fmt.Sprintf("%s/api/v1/repos/%s/%s/contents", c.baseURL, url.PathEscape(owner), url.PathEscape(repo))
+	} else {
+		reqURL = fmt.Sprintf("%s/api/v1/repos/%s/%s/contents/%s", c.baseURL, url.PathEscape(owner), url.PathEscape(repo), escapePath(path))
+	}
+	body, err := c.doGet(ctx, reqURL)
 	if err != nil {
 		return nil, fmt.Errorf("list contents %s: %w", path, err)
 	}
@@ -213,10 +278,15 @@ func (c *Client) GetAllFilesInPath(ctx context.Context, owner, repo, path string
 	// Try listing as directory first
 	entries, err := c.ListContents(ctx, owner, repo, path)
 	if err != nil {
-		// Might be a file, try fetching directly
+		// Only fall back to single-file fetch on 404 (path is a file, not a dir).
+		// Propagate all other errors (auth failures, server errors, rate limits).
+		if !IsNotFound(err) {
+			return nil, fmt.Errorf("list contents %q: %w", path, err)
+		}
+		// 404 means the path might be a file — try fetching directly
 		content, fileErr := c.GetFileContent(ctx, owner, repo, path)
 		if fileErr != nil {
-			return nil, fmt.Errorf("path %q is neither a file nor directory: %w", path, err)
+			return nil, fmt.Errorf("path %q is neither a file nor directory: %w", path, fileErr)
 		}
 		results[path] = content
 		return results, nil
@@ -227,14 +297,14 @@ func (c *Client) GetAllFilesInPath(ctx context.Context, owner, repo, path string
 		case "file":
 			content, err := c.GetFileContent(ctx, owner, repo, entry.Path)
 			if err != nil {
-				log.Printf("Warning: could not fetch file %s: %v", entry.Path, err)
+				slog.Warn("could not fetch file from patterns repo", "file", entry.Path, "error", err)
 				continue
 			}
 			results[entry.Path] = content
 		case "dir":
 			subResults, err := c.GetAllFilesInPath(ctx, owner, repo, entry.Path)
 			if err != nil {
-				log.Printf("Warning: could not recurse into %s: %v", entry.Path, err)
+				slog.Warn("could not recurse into directory", "dir", entry.Path, "error", err)
 				continue
 			}
 			for k, v := range subResults {
@@ -244,3 +314,322 @@ func (c *Client) GetAllFilesInPath(ctx context.Context, owner, repo, path string
 	}
 	return results, nil
 }
+
+// Review represents a pull request review from the Gitea API.
+type Review struct {
+	ID       int64  `json:"id"`
+	Body     string `json:"body"`
+	User     struct {
+		Login string `json:"login"`
+	} `json:"user"`
+	State    string `json:"state"`
+	Stale    bool   `json:"stale"`
+	CommitID string `json:"commit_id"`
+}
+
+// ListReviews returns all reviews on a pull request.
+// Paginates through all pages to ensure no reviews are missed.
+func (c *Client) ListReviews(ctx context.Context, owner, repo string, number int) ([]Review, error) {
+	const pageSize = 50
+	var all []Review
+	for page := 1; ; page++ {
+		reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews?limit=%d&page=%d",
+			c.baseURL,
+			url.PathEscape(owner),
+			url.PathEscape(repo),
+			number,
+			pageSize,
+			page)
+		body, err := c.doGet(ctx, reqURL)
+		if err != nil {
+			return nil, fmt.Errorf("list reviews (page %d): %w", page, err)
+		}
+		var batch []Review
+		if err := json.Unmarshal(body, &batch); err != nil {
+			return nil, fmt.Errorf("parse reviews (page %d): %w", page, err)
+		}
+		all = append(all, batch...)
+		if len(batch) < pageSize {
+			break
+		}
+	}
+	return all, nil
+}
+
+// DeleteReview deletes a review by ID. The token must belong to the review author.
+func (c *Client) DeleteReview(ctx context.Context, owner, repo string, number int, reviewID int64) error {
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews/%d",
+		c.baseURL,
+		url.PathEscape(owner),
+		url.PathEscape(repo),
+		number,
+		reviewID)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodDelete, reqURL, nil)
+	if err != nil {
+		return fmt.Errorf("create delete request: %w", err)
+	}
+	req.Header.Set("Authorization", "token "+c.token)
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return fmt.Errorf("delete review: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		respBody, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("delete review failed (status %d): %s", resp.StatusCode, string(respBody))
+	}
+	return nil
+}
+
+// TimelineEvent represents an entry from the issue timeline API.
+type TimelineEvent struct {
+	ID   int64  `json:"id"`
+	Type string `json:"type"`
+	Body string `json:"body"`
+	User struct {
+		Login string `json:"login"`
+	} `json:"user"`
+}
+
+// GetTimelineReviewCommentID finds the comment ID for a review body by
+// scanning the issue timeline for a review event containing the sentinel.
+func (c *Client) GetTimelineReviewCommentID(ctx context.Context, owner, repo string, number int, sentinel string) (int64, error) {
+	const pageSize = 50
+	for page := 1; ; page++ {
+		reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/issues/%d/timeline?limit=%d&page=%d",
+			c.baseURL,
+			url.PathEscape(owner),
+			url.PathEscape(repo),
+			number,
+			pageSize,
+			page)
+		body, err := c.doGet(ctx, reqURL)
+		if err != nil {
+			return 0, fmt.Errorf("get timeline (page %d): %w", page, err)
+		}
+		var events []TimelineEvent
+		if err := json.Unmarshal(body, &events); err != nil {
+			return 0, fmt.Errorf("parse timeline (page %d): %w", page, err)
+		}
+		for _, ev := range events {
+			if ev.Type == "review" && strings.Contains(ev.Body, sentinel) {
+				return ev.ID, nil
+			}
+		}
+		if len(events) < pageSize {
+			break
+		}
+	}
+	return 0, fmt.Errorf("no timeline event found with sentinel")
+}
+
+// GetTimelineReviewCommentIDForReview finds the timeline comment ID for a
+// specific review by matching its body content in the timeline.
+func (c *Client) GetTimelineReviewCommentIDForReview(ctx context.Context, owner, repo string, number int, reviewID int64) (int64, error) {
+	// Use the reviews API to get the review body, then find in timeline
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews/%d",
+		c.baseURL,
+		url.PathEscape(owner),
+		url.PathEscape(repo),
+		number,
+		reviewID)
+	body, err := c.doGet(ctx, reqURL)
+	if err != nil {
+		return 0, fmt.Errorf("get review %d: %w", reviewID, err)
+	}
+	var review struct {
+		Body string `json:"body"`
+		User struct {
+			Login string `json:"login"`
+		} `json:"user"`
+	}
+	if err := json.Unmarshal(body, &review); err != nil {
+		return 0, fmt.Errorf("parse review %d: %w", reviewID, err)
+	}
+	if review.Body == "" {
+		return 0, fmt.Errorf("review %d has empty body", reviewID)
+	}
+
+	// Use a prefix for matching (handles minor trailing whitespace differences)
+	matchPrefix := review.Body
+	if len(matchPrefix) > 200 {
+		matchPrefix = matchPrefix[:200]
+	}
+
+	const pageSize = 50
+	for page := 1; ; page++ {
+		timelineURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/issues/%d/timeline?limit=%d&page=%d",
+			c.baseURL,
+			url.PathEscape(owner),
+			url.PathEscape(repo),
+			number,
+			pageSize,
+			page)
+		tlBody, err := c.doGet(ctx, timelineURL)
+		if err != nil {
+			return 0, fmt.Errorf("get timeline (page %d): %w", page, err)
+		}
+		var events []TimelineEvent
+		if err := json.Unmarshal(tlBody, &events); err != nil {
+			return 0, fmt.Errorf("parse timeline (page %d): %w", page, err)
+		}
+		for _, ev := range events {
+			if ev.Type == "review" && ev.User.Login == review.User.Login && strings.HasPrefix(ev.Body, matchPrefix) {
+				return ev.ID, nil
+			}
+		}
+		if len(events) < pageSize {
+			break
+		}
+	}
+	return 0, fmt.Errorf("no timeline event found for review %d", reviewID)
+}
+
+// EditComment updates the body of an issue/review comment.
+func (c *Client) EditComment(ctx context.Context, owner, repo string, commentID int64, newBody string) error {
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/issues/comments/%d",
+		c.baseURL,
+		url.PathEscape(owner),
+		url.PathEscape(repo),
+		commentID)
+
+	payload := struct {
+		Body string `json:"body"`
+	}{Body: newBody}
+	data, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("marshal edit payload: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPatch, reqURL, bytes.NewReader(data))
+	if err != nil {
+		return fmt.Errorf("create edit request: %w", err)
+	}
+	req.Header.Set("Authorization", "token "+c.token)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return fmt.Errorf("edit comment: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("edit comment failed (status %d): %s", resp.StatusCode, body)
+	}
+	return nil
+}
+
+// GetAuthenticatedUser returns the login of the user authenticated by the token.
+func (c *Client) GetAuthenticatedUser(ctx context.Context) (string, error) {
+	reqURL := fmt.Sprintf("%s/api/v1/user", c.baseURL)
+	body, err := c.doGet(ctx, reqURL)
+	if err != nil {
+		return "", fmt.Errorf("get authenticated user: %w", err)
+	}
+	var result struct {
+		Login string `json:"login"`
+	}
+	if err := json.Unmarshal(body, &result); err != nil {
+		return "", fmt.Errorf("parse user response: %w", err)
+	}
+	return result.Login, nil
+}
+
+// RequestReviewer adds the given user as a requested reviewer on a pull request.
+// This is idempotent — requesting an already-requested reviewer is a no-op.
+func (c *Client) RequestReviewer(ctx context.Context, owner, repo string, number int, reviewer string) error {
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/requested_reviewers",
+		c.baseURL,
+		url.PathEscape(owner),
+		url.PathEscape(repo),
+		number)
+
+	payload := struct {
+		Reviewers []string `json:"reviewers"`
+	}{Reviewers: []string{reviewer}}
+	data, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("marshal reviewer request: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, reqURL, bytes.NewReader(data))
+	if err != nil {
+		return fmt.Errorf("create reviewer request: %w", err)
+	}
+	req.Header.Set("Authorization", "token "+c.token)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return fmt.Errorf("request reviewer: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusNoContent {
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 256))
+		return fmt.Errorf("request reviewer failed (status %d): %s", resp.StatusCode, body)
+	}
+	return nil
+}
+
+// ListReviewComments returns the inline comments attached to a specific review.
+// Paginates through all pages.
+func (c *Client) ListReviewComments(ctx context.Context, owner, repo string, prNumber int, reviewID int64) ([]ReviewComment, error) {
+	const pageSize = 50
+	var all []ReviewComment
+	for page := 1; ; page++ {
+		reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/%d/reviews/%d/comments?limit=%d&page=%d",
+			c.baseURL,
+			url.PathEscape(owner),
+			url.PathEscape(repo),
+			prNumber,
+			reviewID,
+			pageSize,
+			page)
+		body, err := c.doGet(ctx, reqURL)
+		if err != nil {
+			return nil, fmt.Errorf("list review comments (page %d): %w", page, err)
+		}
+		var batch []ReviewComment
+		if err := json.Unmarshal(body, &batch); err != nil {
+			return nil, fmt.Errorf("parse review comments (page %d): %w", page, err)
+		}
+		all = append(all, batch...)
+		if len(batch) < pageSize {
+			break
+		}
+	}
+	return all, nil
+}
+
+// ResolveComment marks an inline review comment as resolved.
+func (c *Client) ResolveComment(ctx context.Context, owner, repo string, commentID int64) error {
+	reqURL := fmt.Sprintf("%s/api/v1/repos/%s/%s/pulls/comments/%d/resolve",
+		c.baseURL,
+		url.PathEscape(owner),
+		url.PathEscape(repo),
+		commentID)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, reqURL, nil)
+	if err != nil {
+		return fmt.Errorf("create resolve request: %w", err)
+	}
+	req.Header.Set("Authorization", "token "+c.token)
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return fmt.Errorf("resolve comment: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK && resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusNoContent {
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 256))
+		return fmt.Errorf("resolve comment failed (status %d): %s", resp.StatusCode, body)
+	}
+	return nil
+}

gitea/client_test.go

@@ -3,9 +3,12 @@ package gitea
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 )
 
@@ -123,15 +126,21 @@ func TestPostReview(t *testing.T) {
 		}
 
 		w.WriteHeader(http.StatusOK)
-		w.Write([]byte(`{}`))
+		w.Write([]byte(`{"id":100,"user":{"login":"review-bot"},"state":"APPROVED","stale":false}`))
 	}))
 	defer server.Close()
 
 	client := NewClient(server.URL, "test-token")
-	err := client.PostReview(context.Background(), "owner", "repo", 3, "APPROVED", "LGTM")
+	review, err := client.PostReview(context.Background(), "owner", "repo", 3, "APPROVED", "LGTM", nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
+	if review.ID != 100 {
+		t.Errorf("expected review ID 100, got %d", review.ID)
+	}
+	if review.User.Login != "review-bot" {
+		t.Errorf("expected user login %q, got %q", "review-bot", review.User.Login)
+	}
 }
 
 func TestGetPullRequest_Non200(t *testing.T) {
@@ -169,7 +178,7 @@ func TestPostReview_Non200(t *testing.T) {
 	defer server.Close()
 
 	client := NewClient(server.URL, "test-token")
-	err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "test")
+	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "test", nil)
 	if err == nil {
 		t.Fatal("expected error for 403, got nil")
 	}
@@ -294,3 +303,443 @@ func TestGetAllFilesInPath_File(t *testing.T) {
 		t.Errorf("unexpected content: %q", files["README.md"])
 	}
 }
+
+func TestEscapePath(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{"simple", "src/main.go", "src/main.go"},
+		{"spaces", "my dir/my file.go", "my%20dir/my%20file.go"},
+		{"special chars", "path/file#1.txt", "path/file%231.txt"},
+		{"empty", "", ""},
+		{"single segment", "README.md", "README.md"},
+		{"nested deep", "a/b/c/d.md", "a/b/c/d.md"},
+		{"already encoded", "path/file%20name.go", "path/file%2520name.go"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := escapePath(tt.input)
+			if got != tt.want {
+				t.Errorf("escapePath(%q) = %q, want %q", tt.input, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestListReviews(t *testing.T) {
+	pageCount := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/5/reviews" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.URL.Query().Get("limit") != "50" {
+			t.Errorf("expected limit=50, got %s", r.URL.Query().Get("limit"))
+		}
+		pageCount++
+		w.Header().Set("Content-Type", "application/json")
+		// Return 2 results (less than page size) to signal end
+		w.Write([]byte(`[{"id":10,"user":{"login":"bot-a"},"state":"APPROVED","stale":false},{"id":11,"user":{"login":"bot-b"},"state":"REQUEST_CHANGES","stale":true}]`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	reviews, err := client.ListReviews(context.Background(), "owner", "repo", 5)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(reviews) != 2 {
+		t.Fatalf("expected 2 reviews, got %d", len(reviews))
+	}
+	if reviews[0].User.Login != "bot-a" {
+		t.Errorf("expected bot-a, got %s", reviews[0].User.Login)
+	}
+	if pageCount != 1 {
+		t.Errorf("expected 1 page fetch (results < page size), got %d", pageCount)
+	}
+}
+
+func TestListReviews_Pagination(t *testing.T) {
+	pageCount := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		pageCount++
+		page := r.URL.Query().Get("page")
+		w.Header().Set("Content-Type", "application/json")
+		if page == "1" {
+			// Return exactly 50 items to trigger next page fetch
+			items := "["
+			for i := 0; i < 50; i++ {
+				if i > 0 {
+					items += ","
+				}
+				items += fmt.Sprintf(`{"id":%d,"user":{"login":"bot"},"state":"APPROVED","stale":false}`, i+1)
+			}
+			items += "]"
+			w.Write([]byte(items))
+		} else {
+			// Page 2: return fewer than 50 to signal end
+			w.Write([]byte(`[{"id":51,"user":{"login":"bot"},"state":"APPROVED","stale":false}]`))
+		}
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	reviews, err := client.ListReviews(context.Background(), "owner", "repo", 5)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(reviews) != 51 {
+		t.Fatalf("expected 51 reviews across 2 pages, got %d", len(reviews))
+	}
+	if pageCount != 2 {
+		t.Errorf("expected 2 page fetches, got %d", pageCount)
+	}
+}
+
+func TestDeleteReview(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/repos/owner/repo/pulls/5/reviews/10" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Method != "DELETE" {
+			t.Errorf("expected DELETE, got %s", r.Method)
+		}
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.DeleteReview(context.Background(), "owner", "repo", 5, 10)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+}
+
+func TestDeleteReview_Forbidden(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+		w.Write([]byte(`{"message":"forbidden"}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.DeleteReview(context.Background(), "owner", "repo", 5, 10)
+	if err == nil {
+		t.Fatal("expected error for 403, got nil")
+	}
+}
+
+func TestEditComment(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPatch {
+			t.Errorf("expected PATCH, got %s", r.Method)
+		}
+		if r.URL.Path != "/api/v1/repos/owner/repo/issues/comments/42" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+
+		var payload struct {
+			Body string `json:"body"`
+		}
+		json.NewDecoder(r.Body).Decode(&payload)
+		if payload.Body != "updated body" {
+			t.Errorf("unexpected body: %s", payload.Body)
+		}
+
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(`{"id": 42, "body": "updated body"}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.EditComment(context.Background(), "owner", "repo", 42, "updated body")
+	if err != nil {
+		t.Fatalf("EditComment() error = %v", err)
+	}
+}
+
+func TestEditComment_Forbidden(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+		w.Write([]byte(`{"message": "not allowed"}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.EditComment(context.Background(), "owner", "repo", 42, "new body")
+	if err == nil {
+		t.Fatal("expected error for 403 response")
+	}
+}
+
+func TestGetTimelineReviewCommentID(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/repos/owner/repo/issues/5/timeline" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		w.Write([]byte(`[
+			{"id": 100, "type": "comment", "body": "random"},
+			{"id": 200, "type": "review", "body": "other review <!-- review-bot:gpt -->"},
+			{"id": 300, "type": "review", "body": "our review <!-- review-bot:sonnet -->"}
+		]`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	id, err := client.GetTimelineReviewCommentID(context.Background(), "owner", "repo", 5, "<!-- review-bot:sonnet -->")
+	if err != nil {
+		t.Fatalf("GetTimelineReviewCommentID() error = %v", err)
+	}
+	if id != 300 {
+		t.Errorf("got id=%d, want 300", id)
+	}
+}
+
+func TestGetTimelineReviewCommentID_NotFound(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(`[{"id": 100, "type": "review", "body": "no match"}]`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	_, err := client.GetTimelineReviewCommentID(context.Background(), "owner", "repo", 5, "<!-- review-bot:sonnet -->")
+	if err == nil {
+		t.Fatal("expected error when sentinel not found")
+	}
+}
+
+func TestGetAllFilesInPath_404FallsBackToFile(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/v1/repos/owner/repo/contents/README.md":
+			// Contents API returns 404 for files (not a directory)
+			w.WriteHeader(http.StatusNotFound)
+			w.Write([]byte(`{"message":"not found"}`))
+		case "/api/v1/repos/owner/repo/raw/README.md":
+			w.Write([]byte("# Hello\n"))
+		default:
+			w.WriteHeader(http.StatusNotFound)
+			w.Write([]byte(`{"message":"not found"}`))
+		}
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	files, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "README.md")
+	if err != nil {
+		t.Fatalf("expected fallback to file on 404, got error: %v", err)
+	}
+	if len(files) != 1 {
+		t.Fatalf("expected 1 file, got %d", len(files))
+	}
+	if files["README.md"] != "# Hello\n" {
+		t.Errorf("unexpected content: %q", files["README.md"])
+	}
+}
+
+func TestGetAllFilesInPath_500Propagates(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// Simulate a server error from ListContents
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte(`{"message":"internal server error"}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	_, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "somepath")
+	if err == nil {
+		t.Fatal("expected error to propagate for 500, got nil")
+	}
+	// Should NOT fall back to file fetch — error should propagate
+	var apiErr *APIError
+	if !errors.As(err, &apiErr) {
+		t.Fatalf("expected APIError in chain, got: %v", err)
+	}
+	if apiErr.StatusCode != http.StatusInternalServerError {
+		t.Errorf("expected status 500, got %d", apiErr.StatusCode)
+	}
+}
+
+func TestGetAllFilesInPath_403Propagates(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+		w.Write([]byte(`{"message":"token has insufficient scope"}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	_, err := client.GetAllFilesInPath(context.Background(), "owner", "repo", "private/stuff")
+	if err == nil {
+		t.Fatal("expected error to propagate for 403, got nil")
+	}
+	var apiErr *APIError
+	if !errors.As(err, &apiErr) {
+		t.Fatalf("expected APIError in chain, got: %v", err)
+	}
+	if apiErr.StatusCode != http.StatusForbidden {
+		t.Errorf("expected status 403, got %d", apiErr.StatusCode)
+	}
+}
+
+func TestIsNotFound(t *testing.T) {
+	tests := []struct {
+		name   string
+		err    error
+		want   bool
+	}{
+		{"nil error", nil, false},
+		{"non-API error", fmt.Errorf("network timeout"), false},
+		{"404 APIError", &APIError{StatusCode: 404, Body: "not found"}, true},
+		{"500 APIError", &APIError{StatusCode: 500, Body: "server error"}, false},
+		{"wrapped 404", fmt.Errorf("list contents: %w", &APIError{StatusCode: 404, Body: "not found"}), true},
+		{"wrapped 500", fmt.Errorf("list contents: %w", &APIError{StatusCode: 500, Body: "err"}), false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := IsNotFound(tt.err)
+			if got != tt.want {
+				t.Errorf("IsNotFound(%v) = %v, want %v", tt.err, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestGetAuthenticatedUser(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/api/v1/user" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+			http.NotFound(w, r)
+			return
+		}
+		if r.Header.Get("Authorization") != "token test-token" {
+			t.Error("missing or wrong auth header")
+		}
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `{"login":"my-bot","id":42}`)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	login, err := client.GetAuthenticatedUser(context.Background())
+	if err != nil {
+		t.Fatalf("GetAuthenticatedUser() error = %v", err)
+	}
+	if login != "my-bot" {
+		t.Errorf("login = %q, want %q", login, "my-bot")
+	}
+}
+
+func TestRequestReviewer(t *testing.T) {
+	var gotBody []byte
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+		expected := "/api/v1/repos/owner/repo/pulls/7/requested_reviewers"
+		if r.URL.Path != expected {
+			t.Errorf("path = %q, want %q", r.URL.Path, expected)
+		}
+		gotBody, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusCreated)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.RequestReviewer(context.Background(), "owner", "repo", 7, "bot-user")
+	if err != nil {
+		t.Fatalf("RequestReviewer() error = %v", err)
+	}
+	if !strings.Contains(string(gotBody), `"bot-user"`) {
+		t.Errorf("body = %s, want to contain bot-user", gotBody)
+	}
+}
+
+func TestRequestReviewer_204(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
+	if err != nil {
+		t.Fatalf("RequestReviewer() should accept 204, got error = %v", err)
+	}
+}
+
+func TestRequestReviewer_Error(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+		fmt.Fprint(w, "no permission")
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.RequestReviewer(context.Background(), "owner", "repo", 1, "user")
+	if err == nil {
+		t.Fatal("expected error for 403 response")
+	}
+	if !strings.Contains(err.Error(), "403") {
+		t.Errorf("error should mention status code: %v", err)
+	}
+}
+
+func TestListReviewComments(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !strings.Contains(r.URL.Path, "/pulls/1/reviews/42/comments") {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprint(w, `[{"id":100,"path":"main.go","new_position":5,"body":"finding"},{"id":101,"path":"lib.go","new_position":10,"body":"another"}]`)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	comments, err := client.ListReviewComments(context.Background(), "owner", "repo", 1, 42)
+	if err != nil {
+		t.Fatalf("ListReviewComments() error = %v", err)
+	}
+	if len(comments) != 2 {
+		t.Fatalf("got %d comments, want 2", len(comments))
+	}
+	if comments[0].ID != 100 {
+		t.Errorf("comments[0].ID = %d, want 100", comments[0].ID)
+	}
+	if comments[1].Path != "lib.go" {
+		t.Errorf("comments[1].Path = %q, want %q", comments[1].Path, "lib.go")
+	}
+}
+
+func TestResolveComment(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Errorf("expected POST, got %s", r.Method)
+		}
+		if !strings.Contains(r.URL.Path, "/pulls/comments/99/resolve") {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.ResolveComment(context.Background(), "owner", "repo", 99)
+	if err != nil {
+		t.Fatalf("ResolveComment() error = %v", err)
+	}
+}
+
+func TestResolveComment_Error(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+		fmt.Fprint(w, "not found")
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	err := client.ResolveComment(context.Background(), "owner", "repo", 99)
+	if err == nil {
+		t.Fatal("expected error for 404 response")
+	}
+}

gitea/diff.go

@@ -0,0 +1,85 @@
+package gitea
+
+import (
+	"strconv"
+	"strings"
+)
+
+// DiffLineRanges maps filenames to the set of new-file line numbers present in the diff.
+type DiffLineRanges struct {
+	files map[string]map[int]bool
+}
+
+// Contains reports whether the given file+line is within the diff hunks.
+func (d *DiffLineRanges) Contains(file string, line int) bool {
+	if d == nil || d.files == nil {
+		return false
+	}
+	lines, ok := d.files[file]
+	if !ok {
+		return false
+	}
+	return lines[line]
+}
+
+// ParseDiffNewLines parses a unified diff and extracts the new-file line numbers
+// that appear in each hunk (both added and context lines).
+func ParseDiffNewLines(diff string) *DiffLineRanges {
+	result := &DiffLineRanges{files: make(map[string]map[int]bool)}
+
+	var currentFile string
+	var newLine int
+
+	for _, line := range strings.Split(diff, "\n") {
+		// Track current file from +++ header
+		if strings.HasPrefix(line, "+++ b/") {
+			currentFile = strings.TrimPrefix(line, "+++ b/")
+			if result.files[currentFile] == nil {
+				result.files[currentFile] = make(map[int]bool)
+			}
+			continue
+		}
+		if strings.HasPrefix(line, "+++ /dev/null") {
+			currentFile = ""
+			continue
+		}
+
+		// Parse hunk header: @@ -old,count +new,count @@ or @@ -old +new @@
+		if strings.HasPrefix(line, "@@") && currentFile != "" {
+			// Extract the +N part — handle both "+10,8" and "+1" forms
+			parts := strings.Split(line, "+")
+			if len(parts) >= 2 {
+				// Take everything before comma or space
+				numStr := parts[1]
+				if idx := strings.IndexAny(numStr, ", "); idx != -1 {
+					numStr = numStr[:idx]
+				}
+				n, err := strconv.Atoi(numStr)
+				if err == nil {
+					newLine = n
+				}
+			}
+			continue
+		}
+
+		if currentFile == "" {
+			continue
+		}
+
+		// Skip diff metadata lines
+		if strings.HasPrefix(line, "\\") {
+			continue
+		}
+
+		// Count lines in hunk
+		if strings.HasPrefix(line, "+") || strings.HasPrefix(line, " ") {
+			result.files[currentFile][newLine] = true
+			newLine++
+		} else if strings.HasPrefix(line, "-") {
+			// Removed lines don't advance new line counter
+			continue
+		}
+	}
+
+	return result
+}

gitea/diff_test.go

@@ -0,0 +1,115 @@
+package gitea
+
+import (
+	"testing"
+)
+
+func TestParseDiffLineRanges(t *testing.T) {
+	diff := `diff --git a/main.go b/main.go
+index abc1234..def5678 100644
+--- a/main.go
++++ b/main.go
+@@ -10,6 +10,8 @@ func main() {
+ 	fmt.Println("hello")
++	fmt.Println("new line 11")
++	fmt.Println("new line 12")
+ 	fmt.Println("existing")
+ }
+@@ -30,4 +32,5 @@ func other() {
+ 	return nil
++	// added at line 33
+ }
+diff --git a/util.go b/util.go
+new file mode 100644
+--- /dev/null
++++ b/util.go
+@@ -0,0 +1,5 @@
++package main
++
++func helper() string {
++	return "hi"
++}
+`
+
+	ranges := ParseDiffNewLines(diff)
+
+	// main.go should have lines 10-17 (first hunk) and 32-36 (second hunk)
+	if !ranges.Contains("main.go", 11) {
+		t.Error("expected main.go:11 to be in diff")
+	}
+	if !ranges.Contains("main.go", 12) {
+		t.Error("expected main.go:12 to be in diff")
+	}
+	if !ranges.Contains("main.go", 10) {
+		t.Error("expected main.go:10 to be in diff (context line)")
+	}
+	if !ranges.Contains("main.go", 33) {
+		t.Error("expected main.go:33 to be in diff")
+	}
+	if ranges.Contains("main.go", 25) {
+		t.Error("main.go:25 should NOT be in diff")
+	}
+
+	// util.go is entirely new, lines 1-5
+	if !ranges.Contains("util.go", 1) {
+		t.Error("expected util.go:1 to be in diff")
+	}
+	if !ranges.Contains("util.go", 5) {
+		t.Error("expected util.go:5 to be in diff")
+	}
+	if ranges.Contains("util.go", 6) {
+		t.Error("util.go:6 should NOT be in diff")
+	}
+
+	// Unknown file
+	if ranges.Contains("unknown.go", 1) {
+		t.Error("unknown.go should not be in diff")
+	}
+}
+
+func TestParseDiffNewLines_Empty(t *testing.T) {
+	ranges := ParseDiffNewLines("")
+	if ranges.Contains("any.go", 1) {
+		t.Error("empty diff should contain nothing")
+	}
+}
+
+func TestParseDiffNewLines_NoCommaHunk(t *testing.T) {
+	// Single-line hunks omit the comma: @@ -1 +1 @@
+	diff := `diff --git a/single.go b/single.go
+--- a/single.go
++++ b/single.go
+@@ -1 +1 @@
+-old line
++new line
+`
+	ranges := ParseDiffNewLines(diff)
+	if !ranges.Contains("single.go", 1) {
+		t.Error("expected single.go:1 to be in diff (no-comma hunk)")
+	}
+	if ranges.Contains("single.go", 2) {
+		t.Error("single.go:2 should NOT be in diff")
+	}
+}
+
+func TestParseDiffNewLines_NoNewlineMarker(t *testing.T) {
+	// "\ No newline at end of file" should not advance line counter
+	diff := `diff --git a/noeof.go b/noeof.go
+--- a/noeof.go
++++ b/noeof.go
+@@ -1,2 +1,2 @@
++line one
++line two
+\ No newline at end of file
+`
+	ranges := ParseDiffNewLines(diff)
+	if !ranges.Contains("noeof.go", 1) {
+		t.Error("expected noeof.go:1")
+	}
+	if !ranges.Contains("noeof.go", 2) {
+		t.Error("expected noeof.go:2")
+	}
+	if ranges.Contains("noeof.go", 3) {
+		t.Error("noeof.go:3 should NOT be in diff (no-newline marker)")
+	}
+}

gitea/post_review_comments_test.go

@@ -0,0 +1,88 @@
+package gitea
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestPostReview_WithComments(t *testing.T) {
+	var gotPayload struct {
+		Body     string `json:"body"`
+		Event    string `json:"event"`
+		Comments []struct {
+			Path        string `json:"path"`
+			NewPosition int64  `json:"new_position"`
+			Body        string `json:"body"`
+		} `json:"comments"`
+	}
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		json.NewDecoder(r.Body).Decode(&gotPayload)
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		json.NewEncoder(w).Encode(map[string]any{
+			"id":   99,
+			"body": gotPayload.Body,
+			"user": map[string]any{"login": "bot"},
+		})
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	comments := []ReviewComment{
+		{Path: "main.go", NewPosition: 42, Body: "[MAJOR] Something bad"},
+		{Path: "util.go", NewPosition: 10, Body: "[MINOR] Style issue"},
+	}
+
+	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "REQUEST_CHANGES", "summary", comments)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if len(gotPayload.Comments) != 2 {
+		t.Fatalf("expected 2 comments, got %d", len(gotPayload.Comments))
+	}
+	if gotPayload.Comments[0].Path != "main.go" {
+		t.Errorf("expected path main.go, got %s", gotPayload.Comments[0].Path)
+	}
+	if gotPayload.Comments[0].NewPosition != 42 {
+		t.Errorf("expected new_position 42, got %d", gotPayload.Comments[0].NewPosition)
+	}
+	if gotPayload.Comments[1].Body != "[MINOR] Style issue" {
+		t.Errorf("unexpected body: %s", gotPayload.Comments[1].Body)
+	}
+}
+
+func TestPostReview_NilComments(t *testing.T) {
+	var gotPayload map[string]any
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		json.NewDecoder(r.Body).Decode(&gotPayload)
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(200)
+		json.NewEncoder(w).Encode(map[string]any{
+			"id":   100,
+			"body": "test",
+			"user": map[string]any{"login": "bot"},
+		})
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-token")
+	_, err := client.PostReview(context.Background(), "owner", "repo", 1, "APPROVED", "all good", nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	// With nil comments, the field should be omitted (omitempty)
+	comments, ok := gotPayload["comments"]
+	if ok && comments != nil {
+		arr, isArr := comments.([]any)
+		if isArr && len(arr) > 0 {
+			t.Error("expected no comments in payload when nil passed")
+		}
+	}
+}

llm/aicore.go

@@ -0,0 +1,381 @@
+package llm
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+)
+
+// AICoreOpenAIAPIVersion is the API version used for OpenAI models through AI Core.
+// Update this when SAP AI Core releases a new stable version.
+const AICoreOpenAIAPIVersion = "2024-12-01-preview"
+
+// AICoreConfig holds SAP AI Core authentication and connection settings.
+type AICoreConfig struct {
+	ClientID      string
+	ClientSecret  string
+	AuthURL       string
+	APIURL        string
+	ResourceGroup string
+}
+
+// AICoreClient wraps AI Core authentication and deployment discovery.
+// Thread-safe for concurrent use after construction.
+type AICoreClient struct {
+	config AICoreConfig
+	http   *http.Client
+
+	mu          sync.RWMutex
+	token       string
+	tokenExpiry time.Time
+	deployments map[string]deployment // model name -> deployment info
+}
+
+type deployment struct {
+	ID  string
+	URL string
+}
+
+// NewAICoreClient creates a new AI Core client with the given configuration.
+// The client uses a default 5-minute timeout; use WithTimeout to customize.
+func NewAICoreClient(cfg AICoreConfig) *AICoreClient {
+	return &AICoreClient{
+		config:      cfg,
+		http:        &http.Client{Timeout: 5 * time.Minute},
+		deployments: make(map[string]deployment),
+	}
+}
+
+// WithTimeout sets the HTTP request timeout for AI Core calls.
+// This should be called during construction, before concurrent use.
+func (c *AICoreClient) WithTimeout(d time.Duration) *AICoreClient {
+	c.http.Timeout = d
+	return c
+}
+
+// getToken returns a valid OAuth token, refreshing if necessary.
+func (c *AICoreClient) getToken(ctx context.Context) (string, error) {
+	c.mu.RLock()
+	if c.token != "" && time.Now().Add(5*time.Minute).Before(c.tokenExpiry) {
+		token := c.token
+		c.mu.RUnlock()
+		return token, nil
+	}
+	c.mu.RUnlock()
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Double-check after acquiring write lock
+	if c.token != "" && time.Now().Add(5*time.Minute).Before(c.tokenExpiry) {
+		return c.token, nil
+	}
+
+	token, expiry, err := c.fetchToken(ctx)
+	if err != nil {
+		return "", err
+	}
+	c.token = token
+	c.tokenExpiry = expiry
+	return token, nil
+}
+
+func (c *AICoreClient) fetchToken(ctx context.Context) (string, time.Time, error) {
+	tokenURL := strings.TrimRight(c.config.AuthURL, "/") + "/oauth/token"
+
+	data := url.Values{}
+	data.Set("grant_type", "client_credentials")
+	data.Set("client_id", c.config.ClientID)
+	data.Set("client_secret", c.config.ClientSecret)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, tokenURL, strings.NewReader(data.Encode()))
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("create token request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("token request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", time.Time{}, fmt.Errorf("read token response: %w", err)
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return "", time.Time{}, fmt.Errorf("token request failed (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	var tokenResp struct {
+		AccessToken string `json:"access_token"`
+		ExpiresIn   int    `json:"expires_in"`
+	}
+	if err := json.Unmarshal(body, &tokenResp); err != nil {
+		return "", time.Time{}, fmt.Errorf("parse token response: %w", err)
+	}
+
+	if tokenResp.AccessToken == "" {
+		return "", time.Time{}, fmt.Errorf("empty access token in response")
+	}
+
+	expiry := time.Now().Add(time.Duration(tokenResp.ExpiresIn) * time.Second)
+	return tokenResp.AccessToken, expiry, nil
+}
+
+// getDeploymentURL returns the deployment URL for a model, fetching deployments if needed.
+func (c *AICoreClient) getDeploymentURL(ctx context.Context, model string) (string, error) {
+	c.mu.RLock()
+	if d, ok := c.deployments[model]; ok {
+		c.mu.RUnlock()
+		return d.URL, nil
+	}
+	c.mu.RUnlock()
+
+	// Fetch token first (before acquiring write lock to avoid deadlock)
+	token, err := c.getToken(ctx)
+	if err != nil {
+		return "", fmt.Errorf("get token for deployments: %w", err)
+	}
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Double-check after acquiring write lock
+	if d, ok := c.deployments[model]; ok {
+		return d.URL, nil
+	}
+
+	if err := c.fetchDeployments(ctx, token); err != nil {
+		return "", err
+	}
+
+	if d, ok := c.deployments[model]; ok {
+		return d.URL, nil
+	}
+	return "", fmt.Errorf("no deployment found for model %q", model)
+}
+
+func (c *AICoreClient) fetchDeployments(ctx context.Context, token string) error {
+	deployURL := strings.TrimRight(c.config.APIURL, "/") + "/v2/lm/deployments"
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, deployURL, nil)
+	if err != nil {
+		return fmt.Errorf("create deployments request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("AI-Resource-Group", c.config.ResourceGroup)
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return fmt.Errorf("deployments request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Errorf("read deployments response: %w", err)
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("deployments request failed (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	var deployResp struct {
+		Resources []struct {
+			ID            string `json:"id"`
+			DeploymentURL string `json:"deploymentUrl"`
+			Status        string `json:"status"`
+			Details       struct {
+				Resources struct {
+					BackendDetails struct {
+						Model struct {
+							Name string `json:"name"`
+						} `json:"model"`
+					} `json:"backend_details"`
+				} `json:"resources"`
+			} `json:"details"`
+		} `json:"resources"`
+	}
+	if err := json.Unmarshal(body, &deployResp); err != nil {
+		return fmt.Errorf("parse deployments response: %w", err)
+	}
+
+	for _, r := range deployResp.Resources {
+		if r.Status != "RUNNING" {
+			continue
+		}
+		modelName := r.Details.Resources.BackendDetails.Model.Name
+		if modelName == "" {
+			continue
+		}
+		c.deployments[modelName] = deployment{
+			ID:  r.ID,
+			URL: r.DeploymentURL,
+		}
+	}
+
+	return nil
+}
+
+// CompleteAnthropic sends a request to an Anthropic model via AI Core.
+func (c *AICoreClient) CompleteAnthropic(ctx context.Context, model string, messages []Message, maxTokens int, temperature float64) (string, error) {
+	deployURL, err := c.getDeploymentURL(ctx, model)
+	if err != nil {
+		return "", err
+	}
+
+	token, err := c.getToken(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	// Extract system message
+	var system string
+	var userMessages []anthropicMsg
+	for _, m := range messages {
+		if m.Role == "system" {
+			system = m.Content
+		} else {
+			userMessages = append(userMessages, anthropicMsg{
+				Role:    m.Role,
+				Content: m.Content,
+			})
+		}
+	}
+
+	reqBody := anthropicRequest{
+		AnthropicVersion: "bedrock-2023-05-31", // SAP AI Core uses Bedrock format
+		// Model omitted - AI Core deployment already specifies model
+		MaxTokens: maxTokens,
+		System:    system,
+		Messages:  userMessages,
+	}
+	if temperature > 0 {
+		reqBody.Temperature = temperature
+	}
+
+	data, err := json.Marshal(reqBody)
+	if err != nil {
+		return "", fmt.Errorf("marshal request: %w", err)
+	}
+
+	// AI Core uses /invoke for Anthropic models
+	invokeURL := strings.TrimRight(deployURL, "/") + "/invoke"
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, invokeURL, bytes.NewReader(data))
+	if err != nil {
+		return "", fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("AI-Resource-Group", c.config.ResourceGroup)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("AI Core request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("read response: %w", err)
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return "", fmt.Errorf("AI Core API error (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	var anthropicResp anthropicResponse
+	if err := json.Unmarshal(body, &anthropicResp); err != nil {
+		return "", fmt.Errorf("parse response: %w", err)
+	}
+
+	if len(anthropicResp.Content) == 0 {
+		return "", fmt.Errorf("no content in response")
+	}
+
+	var sb strings.Builder
+	for _, block := range anthropicResp.Content {
+		if block.Type == "text" {
+			sb.WriteString(block.Text)
+		}
+	}
+	result := sb.String()
+	if result == "" {
+		return "", fmt.Errorf("no text content in response")
+	}
+	return result, nil
+}
+
+// CompleteOpenAI sends a request to an OpenAI model via AI Core.
+func (c *AICoreClient) CompleteOpenAI(ctx context.Context, model string, messages []Message, temperature float64) (string, error) {
+	deployURL, err := c.getDeploymentURL(ctx, model)
+	if err != nil {
+		return "", err
+	}
+
+	token, err := c.getToken(ctx)
+	if err != nil {
+		return "", err
+	}
+
+	reqBody := ChatRequest{
+		Model:       model,
+		Temperature: temperature,
+		Messages:    messages,
+	}
+
+	data, err := json.Marshal(reqBody)
+	if err != nil {
+		return "", fmt.Errorf("marshal request: %w", err)
+	}
+
+	// AI Core uses /chat/completions?api-version=<version> for OpenAI models
+	chatURL := strings.TrimRight(deployURL, "/") + "/chat/completions?api-version=" + AICoreOpenAIAPIVersion
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, chatURL, bytes.NewReader(data))
+	if err != nil {
+		return "", fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("AI-Resource-Group", c.config.ResourceGroup)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("AI Core request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("read response: %w", err)
+	}
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return "", fmt.Errorf("AI Core API error (status %d): %s", resp.StatusCode, string(body))
+	}
+
+	var openaiResp ChatResponse
+	if err := json.Unmarshal(body, &openaiResp); err != nil {
+		return "", fmt.Errorf("parse response: %w", err)
+	}
+
+	if len(openaiResp.Choices) == 0 {
+		return "", fmt.Errorf("no choices in response")
+	}
+	return openaiResp.Choices[0].Message.Content, nil
+}
+
+// IsAnthropicModel returns true if the model name indicates an Anthropic model.
+// SAP AI Core uses "anthropic--" prefix for Anthropic models (e.g., "anthropic--claude-3-5-sonnet").
+func IsAnthropicModel(model string) bool {
+	return strings.HasPrefix(model, "anthropic--")
+}

llm/aicore_test.go

@@ -0,0 +1,535 @@
+package llm
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestAICoreClient_TokenFetch(t *testing.T) {
+	tokenCalls := int32(0)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/oauth/token" {
+			atomic.AddInt32(&tokenCalls, 1)
+			if r.Method != http.MethodPost {
+				t.Errorf("expected POST for token, got %s", r.Method)
+			}
+			if r.Header.Get("Content-Type") != "application/x-www-form-urlencoded" {
+				t.Errorf("expected form content type")
+			}
+			w.Header().Set("Content-Type", "application/json")
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"access_token": "test-token-123",
+				"expires_in":   3600,
+			})
+			return
+		}
+		t.Errorf("unexpected path: %s", r.URL.Path)
+	}))
+	defer server.Close()
+
+	client := NewAICoreClient(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       server.URL,
+		APIURL:        server.URL,
+		ResourceGroup: "default",
+	})
+
+	token, err := client.getToken(context.Background())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if token != "test-token-123" {
+		t.Errorf("expected token 'test-token-123', got %q", token)
+	}
+
+	// Second call should use cached token
+	token2, err := client.getToken(context.Background())
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if token2 != "test-token-123" {
+		t.Errorf("expected cached token")
+	}
+	if atomic.LoadInt32(&tokenCalls) != 1 {
+		t.Errorf("expected 1 token call (cached), got %d", tokenCalls)
+	}
+}
+
+func TestAICoreClient_DeploymentFetch(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/oauth/token" {
+			w.Header().Set("Content-Type", "application/json")
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"access_token": "test-token",
+				"expires_in":   3600,
+			})
+			return
+		}
+		if r.URL.Path == "/v2/lm/deployments" {
+			if r.Header.Get("Authorization") != "Bearer test-token" {
+				t.Errorf("expected Bearer auth")
+			}
+			if r.Header.Get("AI-Resource-Group") != "default" {
+				t.Errorf("expected resource group header")
+			}
+			w.Header().Set("Content-Type", "application/json")
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"resources": []map[string]interface{}{
+					{
+						"id":            "deploy-123",
+						"deploymentUrl": "https://example.com/v2/inference/deployments/deploy-123",
+						"status":        "RUNNING",
+						"details": map[string]interface{}{
+							"resources": map[string]interface{}{
+								"backend_details": map[string]interface{}{
+									"model": map[string]interface{}{
+										"name": "anthropic--claude-4.6-sonnet",
+									},
+								},
+							},
+						},
+					},
+					{
+						"id":            "deploy-456",
+						"deploymentUrl": "https://example.com/v2/inference/deployments/deploy-456",
+						"status":        "STOPPED",
+						"details": map[string]interface{}{
+							"resources": map[string]interface{}{
+								"backend_details": map[string]interface{}{
+									"model": map[string]interface{}{
+										"name": "gpt-5",
+									},
+								},
+							},
+						},
+					},
+					{
+						"id":            "deploy-789",
+						"deploymentUrl": "https://example.com/v2/inference/deployments/deploy-789",
+						"status":        "RUNNING",
+						"details": map[string]interface{}{
+							"resources": map[string]interface{}{
+								"backend_details": map[string]interface{}{
+									"model": map[string]interface{}{
+										"name": "gpt-5",
+									},
+								},
+							},
+						},
+					},
+				},
+			})
+			return
+		}
+		t.Errorf("unexpected path: %s", r.URL.Path)
+	}))
+	defer server.Close()
+
+	client := NewAICoreClient(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       server.URL,
+		APIURL:        server.URL,
+		ResourceGroup: "default",
+	})
+
+	// Should find running deployment
+	url, err := client.getDeploymentURL(context.Background(), "anthropic--claude-4.6-sonnet")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if url != "https://example.com/v2/inference/deployments/deploy-123" {
+		t.Errorf("unexpected URL: %s", url)
+	}
+
+	// Should find running gpt-5, not stopped one
+	url, err = client.getDeploymentURL(context.Background(), "gpt-5")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if url != "https://example.com/v2/inference/deployments/deploy-789" {
+		t.Errorf("unexpected URL: %s", url)
+	}
+
+	// Should error on unknown model
+	_, err = client.getDeploymentURL(context.Background(), "unknown-model")
+	if err == nil {
+		t.Error("expected error for unknown model")
+	}
+}
+
+func TestAICoreClient_CompleteAnthropic(t *testing.T) {
+	// Use a pointer to capture the server URL for use in the handler
+	var baseURL string
+	mux := http.NewServeMux()
+	mux.HandleFunc("/oauth/token", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"access_token": "test-token",
+			"expires_in":   3600,
+		})
+	})
+	mux.HandleFunc("/v2/lm/deployments", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"resources": []map[string]interface{}{
+				{
+					"id":            "deploy-anthropic",
+					"deploymentUrl": baseURL + "/deployments/anthropic",
+					"status":        "RUNNING",
+					"details": map[string]interface{}{
+						"resources": map[string]interface{}{
+							"backend_details": map[string]interface{}{
+								"model": map[string]interface{}{
+									"name": "anthropic--claude-4.6-sonnet",
+								},
+							},
+						},
+					},
+				},
+			},
+		})
+	})
+	mux.HandleFunc("/deployments/anthropic/invoke", func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("Authorization") != "Bearer test-token" {
+			t.Errorf("expected Bearer auth on invoke")
+		}
+		var req anthropicRequest
+		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+			t.Fatalf("decode request: %v", err)
+		}
+		if req.AnthropicVersion != "bedrock-2023-05-31" {
+			t.Errorf("expected bedrock anthropic_version in request")
+		}
+		if req.System != "You are helpful" {
+			t.Errorf("expected system prompt: %q", req.System)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"content": []map[string]interface{}{
+				{"type": "text", "text": "Hello from AI Core!"},
+			},
+		})
+	})
+
+	server := httptest.NewServer(mux)
+	baseURL = server.URL
+	defer server.Close()
+
+	client := NewAICoreClient(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       server.URL,
+		APIURL:        server.URL,
+		ResourceGroup: "default",
+	})
+
+	result, err := client.CompleteAnthropic(context.Background(), "anthropic--claude-4.6-sonnet", []Message{
+		{Role: "system", Content: "You are helpful"},
+		{Role: "user", Content: "Hello"},
+	}, 8192, 0)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if result != "Hello from AI Core!" {
+		t.Errorf("expected 'Hello from AI Core!', got %q", result)
+	}
+}
+
+func TestAICoreClient_CompleteOpenAI(t *testing.T) {
+	var baseURL string
+	mux := http.NewServeMux()
+	mux.HandleFunc("/oauth/token", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"access_token": "test-token",
+			"expires_in":   3600,
+		})
+	})
+	mux.HandleFunc("/v2/lm/deployments", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"resources": []map[string]interface{}{
+				{
+					"id":            "deploy-openai",
+					"deploymentUrl": baseURL + "/deployments/openai",
+					"status":        "RUNNING",
+					"details": map[string]interface{}{
+						"resources": map[string]interface{}{
+							"backend_details": map[string]interface{}{
+								"model": map[string]interface{}{
+									"name": "gpt-5",
+								},
+							},
+						},
+					},
+				},
+			},
+		})
+	})
+	mux.HandleFunc("/deployments/openai/chat/completions", func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Query().Get("api-version") != AICoreOpenAIAPIVersion {
+			t.Errorf("expected api-version %s, got %s", AICoreOpenAIAPIVersion, r.URL.Query().Get("api-version"))
+		}
+		var req ChatRequest
+		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+			t.Fatalf("decode request: %v", err)
+		}
+		if req.Model != "gpt-5" {
+			t.Errorf("expected model gpt-5, got %s", req.Model)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(ChatResponse{
+			Choices: []struct {
+				Message struct {
+					Content string `json:"content"`
+				} `json:"message"`
+			}{
+				{Message: struct {
+					Content string `json:"content"`
+				}{Content: "Hello from GPT-5!"}},
+			},
+		})
+	})
+
+	server := httptest.NewServer(mux)
+	baseURL = server.URL
+	defer server.Close()
+
+	client := NewAICoreClient(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       server.URL,
+		APIURL:        server.URL,
+		ResourceGroup: "default",
+	})
+
+	result, err := client.CompleteOpenAI(context.Background(), "gpt-5", []Message{
+		{Role: "user", Content: "Hello"},
+	}, 0)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if result != "Hello from GPT-5!" {
+		t.Errorf("expected 'Hello from GPT-5!', got %q", result)
+	}
+}
+
+func TestIsAnthropicModel(t *testing.T) {
+	tests := []struct {
+		model    string
+		expected bool
+	}{
+		// SAP AI Core uses "anthropic--" prefix for Anthropic models
+		{"anthropic--claude-4.6-sonnet", true},
+		{"anthropic--claude-4.6-opus", true},
+		{"anthropic--claude-3-5-sonnet", true},
+		// Non-prefixed model names are not detected as Anthropic
+		// (SAP AI Core always uses the prefix for Anthropic models)
+		{"claude-sonnet-4", false},
+		{"gpt-5", false},
+		{"gpt-4.1", false},
+		{"llama-3", false},
+		{"my-claude-model", false}, // Avoid false positives on "claude" substring
+	}
+
+	for _, tt := range tests {
+		got := IsAnthropicModel(tt.model)
+		if got != tt.expected {
+			t.Errorf("IsAnthropicModel(%q) = %v, want %v", tt.model, got, tt.expected)
+		}
+	}
+}
+
+func TestAICoreClient_TokenExpiry(t *testing.T) {
+	tokenCalls := int32(0)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/oauth/token" {
+			call := atomic.AddInt32(&tokenCalls, 1)
+			w.Header().Set("Content-Type", "application/json")
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"access_token": fmt.Sprintf("token-%d", call),
+				"expires_in":   1, // 1 second expiry
+			})
+			return
+		}
+	}))
+	defer server.Close()
+
+	client := NewAICoreClient(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       server.URL,
+		APIURL:        server.URL,
+		ResourceGroup: "default",
+	})
+
+	// First call
+	token1, err := client.getToken(context.Background())
+	if err != nil {
+		t.Fatalf("first getToken: %v", err)
+	}
+
+	// Force token expiry by manipulating expiry time
+	client.mu.Lock()
+	client.tokenExpiry = time.Now().Add(-time.Hour)
+	client.mu.Unlock()
+
+	// Should fetch new token
+	token2, err := client.getToken(context.Background())
+	if err != nil {
+		t.Fatalf("second getToken: %v", err)
+	}
+
+	if token1 == token2 {
+		t.Error("expected different tokens after expiry")
+	}
+	if atomic.LoadInt32(&tokenCalls) != 2 {
+		t.Errorf("expected 2 token calls, got %d", tokenCalls)
+	}
+}
+
+func TestAICoreClient_WithTimeout(t *testing.T) {
+	client := NewAICoreClient(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       "https://auth.example.com",
+		APIURL:        "https://api.example.com",
+		ResourceGroup: "default",
+	})
+
+	// Default timeout is 5 minutes
+	if client.http.Timeout != 5*time.Minute {
+		t.Errorf("expected default timeout 5m, got %v", client.http.Timeout)
+	}
+
+	// WithTimeout should update the timeout
+	client.WithTimeout(10 * time.Minute)
+	if client.http.Timeout != 10*time.Minute {
+		t.Errorf("expected timeout 10m, got %v", client.http.Timeout)
+	}
+}
+
+func TestClient_WithAICore(t *testing.T) {
+	client := NewClient("http://example.com", "key", "model")
+	if client.provider != ProviderOpenAI {
+		t.Errorf("expected default provider openai, got %s", client.provider)
+	}
+
+	client.WithAICore(AICoreConfig{
+		ClientID:      "id",
+		ClientSecret:  "secret",
+		AuthURL:       "https://auth.example.com",
+		APIURL:        "https://api.example.com",
+		ResourceGroup: "default",
+	})
+
+	if client.provider != ProviderAICore {
+		t.Errorf("expected provider aicore, got %s", client.provider)
+	}
+	if client.aicore == nil {
+		t.Error("expected aicore client to be set")
+	}
+}
+
+func TestClient_WithTimeout_PropagatestoAICore(t *testing.T) {
+	client := NewClient("http://example.com", "key", "model").
+		WithAICore(AICoreConfig{
+			ClientID:      "id",
+			ClientSecret:  "secret",
+			AuthURL:       "https://auth.example.com",
+			APIURL:        "https://api.example.com",
+			ResourceGroup: "default",
+		})
+
+	// Default should be 5 minutes (inherited from parent client)
+	if client.aicore.http.Timeout != 5*time.Minute {
+		t.Errorf("expected aicore default timeout 5m, got %v", client.aicore.http.Timeout)
+	}
+
+	// WithTimeout should propagate to AI Core client
+	client.WithTimeout(15 * time.Minute)
+	if client.http.Timeout != 15*time.Minute {
+		t.Errorf("expected parent timeout 15m, got %v", client.http.Timeout)
+	}
+	if client.aicore.http.Timeout != 15*time.Minute {
+		t.Errorf("expected aicore timeout 15m, got %v", client.aicore.http.Timeout)
+	}
+}
+
+func TestClient_CompleteAICore(t *testing.T) {
+	var baseURL string
+	mux := http.NewServeMux()
+	mux.HandleFunc("/oauth/token", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"access_token": "test-token",
+			"expires_in":   3600,
+		})
+	})
+	mux.HandleFunc("/v2/lm/deployments", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(map[string]interface{}{
+			"resources": []map[string]interface{}{
+				{
+					"id":            "deploy-test",
+					"deploymentUrl": baseURL + "/deployments/test",
+					"status":        "RUNNING",
+					"details": map[string]interface{}{
+						"resources": map[string]interface{}{
+							"backend_details": map[string]interface{}{
+								"model": map[string]interface{}{
+									"name": "gpt-5",
+								},
+							},
+						},
+					},
+				},
+			},
+		})
+	})
+	mux.HandleFunc("/deployments/test/chat/completions", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(ChatResponse{
+			Choices: []struct {
+				Message struct {
+					Content string `json:"content"`
+				} `json:"message"`
+			}{
+				{Message: struct {
+					Content string `json:"content"`
+				}{Content: "AI Core via Client works!"}},
+			},
+		})
+	})
+
+	server := httptest.NewServer(mux)
+	baseURL = server.URL
+	defer server.Close()
+
+	client := NewClient("", "", "gpt-5").WithAICore(AICoreConfig{
+		ClientID:      "test-id",
+		ClientSecret:  "test-secret",
+		AuthURL:       server.URL,
+		APIURL:        server.URL,
+		ResourceGroup: "default",
+	})
+
+	result, err := client.Complete(context.Background(), []Message{
+		{Role: "user", Content: "Hello"},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if !strings.Contains(result, "AI Core via Client works!") {
+		t.Errorf("unexpected result: %s", result)
+	}
+}

llm/client.go

@@ -1,3 +1,6 @@
+// Package llm provides clients for LLM chat completion APIs.
+//
+// Supports OpenAI-compatible (default), Anthropic Messages API, and SAP AI Core providers.
 package llm
 
 import (
@@ -11,30 +14,50 @@ import (
 	"time"
 )
 
-// Client calls an OpenAI-compatible chat completion API.
+// Provider identifies which API format to use.
+type Provider string
+
+const (
+	// ProviderOpenAI uses the OpenAI-compatible chat/completions endpoint.
+	ProviderOpenAI Provider = "openai"
+	// ProviderAnthropic uses the Anthropic Messages API endpoint.
+	ProviderAnthropic Provider = "anthropic"
+	// ProviderAICore uses SAP AI Core with OAuth authentication.
+	ProviderAICore Provider = "aicore"
+)
+
+// Client calls an LLM chat completion API.
 // A Client is safe for concurrent use by multiple goroutines after construction.
-// WithTimeout and WithTemperature must be called during setup, before concurrent use.
+// WithTimeout, WithTemperature, and WithProvider must be called during setup,
+// before concurrent use.
 type Client struct {
 	baseURL     string
 	apiKey      string
 	model       string
 	temperature float64
+	provider    Provider
 	http        *http.Client
+	aicore      *AICoreClient // Only set when provider is aicore
 }
 
-// NewClient creates a new LLM client.
+// NewClient creates a new LLM client. Default provider is OpenAI-compatible.
 func NewClient(baseURL, apiKey, model string) *Client {
 	return &Client{
-		baseURL: strings.TrimRight(baseURL, "/"),
+		baseURL:  strings.TrimRight(baseURL, "/"),
-		apiKey:  apiKey,
+		apiKey:   apiKey,
-		model:   model,
+		model:    model,
-		http:    &http.Client{Timeout: 5 * time.Minute},
+		provider: ProviderOpenAI,
+		http:     &http.Client{Timeout: 5 * time.Minute},
 	}
 }
 
 // WithTimeout sets the HTTP request timeout for LLM calls (default 5 minutes).
+// When using AI Core, this also sets the timeout on the AI Core client.
 func (c *Client) WithTimeout(d time.Duration) *Client {
 	c.http.Timeout = d
+	if c.aicore != nil {
+		c.aicore.WithTimeout(d)
+	}
 	return c
 }
 
@@ -44,20 +67,102 @@ func (c *Client) WithTemperature(t float64) *Client {
 	return c
 }
 
+// WithProvider sets the API provider format (openai, anthropic, or aicore).
+func (c *Client) WithProvider(p Provider) *Client {
+	c.provider = p
+	return c
+}
+
+// WithAICore configures the client to use SAP AI Core for authentication.
+// This sets the provider to aicore automatically.
+// The AI Core client inherits the current HTTP timeout from this client.
+func (c *Client) WithAICore(cfg AICoreConfig) *Client {
+	c.provider = ProviderAICore
+	c.aicore = NewAICoreClient(cfg).WithTimeout(c.http.Timeout)
+	return c
+}
+
 // Message represents a chat message.
 type Message struct {
 	Role    string `json:"role"`
 	Content string `json:"content"`
 }
 
-// ChatRequest is the request payload.
+// Complete sends a chat completion request and returns the assistant's response content.
+// The first message with role "system" is treated as the system prompt.
+func (c *Client) Complete(ctx context.Context, messages []Message) (string, error) {
+	var result string
+	var err error
+
+	for attempt := 0; attempt < 2; attempt++ {
+		switch c.provider {
+		case ProviderAnthropic:
+			result, err = c.completeAnthropic(ctx, messages)
+		case ProviderAICore:
+			result, err = c.completeAICore(ctx, messages)
+		default:
+			result, err = c.completeOpenAI(ctx, messages)
+		}
+
+		if err == nil {
+			return result, nil
+		}
+
+		// Only retry on response body read errors (transient network issues).
+		// Do not retry on context cancellation, status errors, or parse errors
+		// that indicate a structural API problem.
+		if !isRetryableError(err) {
+			return "", err
+		}
+
+		if attempt == 0 && ctx.Err() == nil {
+			// Brief pause before retry to allow transient issues to resolve.
+			time.Sleep(500 * time.Millisecond)
+		}
+	}
+
+	return "", err
+}
+
+// completeAICore routes to AI Core using the appropriate endpoint based on model type.
+func (c *Client) completeAICore(ctx context.Context, messages []Message) (string, error) {
+	if c.aicore == nil {
+		return "", fmt.Errorf("AI Core client not configured")
+	}
+
+	if IsAnthropicModel(c.model) {
+		return c.aicore.CompleteAnthropic(ctx, c.model, messages, 8192, c.temperature)
+	}
+	return c.aicore.CompleteOpenAI(ctx, c.model, messages, c.temperature)
+}
+
+// isRetryableError returns true for transient errors worth retrying.
+func isRetryableError(err error) bool {
+	if err == nil {
+		return false
+	}
+	s := err.Error()
+	// Body read failures (connection reset, truncation)
+	if strings.Contains(s, "read response") {
+		return true
+	}
+	// Unexpected body length (our content-length validation)
+	if strings.Contains(s, "body length mismatch") {
+		return true
+	}
+	return false
+}
+
+// --- OpenAI-compatible implementation ---
+
+// ChatRequest is the OpenAI request payload.
 type ChatRequest struct {
 	Model       string    `json:"model"`
 	Messages    []Message `json:"messages"`
 	Temperature float64   `json:"temperature,omitempty"`
 }
 
-// ChatResponse is the response from the API.
+// ChatResponse is the OpenAI response.
 type ChatResponse struct {
 	Choices []struct {
 		Message struct {
@@ -66,8 +171,7 @@ type ChatResponse struct {
 	} `json:"choices"`
 }
 
-// Complete sends a chat completion request and returns the assistant's response content.
+func (c *Client) completeOpenAI(ctx context.Context, messages []Message) (string, error) {
-func (c *Client) Complete(ctx context.Context, messages []Message) (string, error) {
 	reqBody := ChatRequest{
 		Model:       c.model,
 		Temperature: c.temperature,
@@ -80,37 +184,133 @@ func (c *Client) Complete(ctx context.Context, messages []Message) (string, erro
 	}
 
 	url := c.baseURL + "/chat/completions"
-	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(data))
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(data))
 	if err != nil {
 		return "", fmt.Errorf("create request: %w", err)
 	}
 	req.Header.Set("Authorization", "Bearer "+c.apiKey)
 	req.Header.Set("Content-Type", "application/json")
 
+	return c.doRequest(req, func(body []byte) (string, error) {
+		var resp ChatResponse
+		if err := json.Unmarshal(body, &resp); err != nil {
+			return "", fmt.Errorf("parse response: %w", err)
+		}
+		if len(resp.Choices) == 0 {
+			return "", fmt.Errorf("no choices in LLM response")
+		}
+		return resp.Choices[0].Message.Content, nil
+	})
+}
+
+// --- Anthropic Messages API implementation ---
+
+type anthropicRequest struct {
+	AnthropicVersion string         `json:"anthropic_version,omitempty"`
+	Model       string         `json:"model,omitempty"`
+	MaxTokens   int            `json:"max_tokens"`
+	System      string         `json:"system,omitempty"`
+	Messages    []anthropicMsg `json:"messages"`
+	Temperature float64        `json:"temperature,omitempty"`
+}
+
+type anthropicMsg struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+type anthropicResponse struct {
+	Content []struct {
+		Type string `json:"type"`
+		Text string `json:"text"`
+	} `json:"content"`
+}
+
+func (c *Client) completeAnthropic(ctx context.Context, messages []Message) (string, error) {
+	// Extract system message (first message with role "system")
+	var system string
+	var userMessages []anthropicMsg
+	for _, m := range messages {
+		if m.Role == "system" {
+			system = m.Content
+		} else {
+			userMessages = append(userMessages, anthropicMsg{
+				Role:    m.Role,
+				Content: m.Content,
+			})
+		}
+	}
+
+	reqBody := anthropicRequest{
+		Model:     c.model,
+		MaxTokens: 8192,
+		System:    system,
+		Messages:  userMessages,
+	}
+	if c.temperature > 0 {
+		reqBody.Temperature = c.temperature
+	}
+
+	data, err := json.Marshal(reqBody)
+	if err != nil {
+		return "", fmt.Errorf("marshal request: %w", err)
+	}
+
+	url := c.baseURL + "/messages"
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(data))
+	if err != nil {
+		return "", fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("x-api-key", c.apiKey)
+	req.Header.Set("anthropic-version", "2023-06-01")
+	req.Header.Set("Content-Type", "application/json")
+
+	return c.doRequest(req, func(body []byte) (string, error) {
+		var resp anthropicResponse
+		if err := json.Unmarshal(body, &resp); err != nil {
+			return "", fmt.Errorf("parse response: %w", err)
+		}
+		if len(resp.Content) == 0 {
+			return "", fmt.Errorf("no content in Anthropic response")
+		}
+		// Concatenate all text blocks
+		var sb strings.Builder
+		for _, block := range resp.Content {
+			if block.Type == "text" {
+				sb.WriteString(block.Text)
+			}
+		}
+		result := sb.String()
+		if result == "" {
+			return "", fmt.Errorf("no text content in Anthropic response")
+		}
+		return result, nil
+	})
+}
+
+// --- Shared HTTP execution ---
+
+func (c *Client) doRequest(req *http.Request, parse func([]byte) (string, error)) (string, error) {
 	resp, err := c.http.Do(req)
 	if err != nil {
 		return "", fmt.Errorf("LLM request: %w", err)
 	}
 	defer resp.Body.Close()
 
-	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		body, _ := io.ReadAll(resp.Body)
-		return "", fmt.Errorf("LLM API error (status %d): %s", resp.StatusCode, string(body))
-	}
-
 	body, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return "", fmt.Errorf("read response: %w", err)
 	}
 
-	var chatResp ChatResponse
+	// Validate body length against Content-Length header when present.
-	if err := json.Unmarshal(body, &chatResp); err != nil {
+	// A mismatch indicates the response was truncated in transit.
-		return "", fmt.Errorf("parse response: %w", err)
+	if cl := resp.ContentLength; cl > 0 && int64(len(body)) < cl {
+		return "", fmt.Errorf("body length mismatch: Content-Length=%d, received=%d", cl, len(body))
 	}
 
-	if len(chatResp.Choices) == 0 {
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
-		return "", fmt.Errorf("no choices in LLM response")
+		return "", fmt.Errorf("LLM API error (status %d): %s", resp.StatusCode, string(body))
 	}
 
-	return chatResp.Choices[0].Message.Content, nil
+	return parse(body)
 }

llm/client_test.go

@@ -3,6 +3,7 @@ package llm
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -208,3 +209,218 @@ func TestWithTimeout(t *testing.T) {
 		t.Error("expected timeout error with 50ms timeout and 200ms server delay")
 	}
 }
+
+
+func TestComplete_Anthropic_Success(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path != "/messages" {
+			t.Errorf("unexpected path: %s", r.URL.Path)
+		}
+		if r.Header.Get("x-api-key") != "test-key" {
+			t.Errorf("expected x-api-key header, got %q", r.Header.Get("x-api-key"))
+		}
+		if r.Header.Get("anthropic-version") != "2023-06-01" {
+			t.Errorf("expected anthropic-version header, got %q", r.Header.Get("anthropic-version"))
+		}
+
+		var req map[string]interface{}
+		json.NewDecoder(r.Body).Decode(&req)
+
+		if req["system"] != "You are helpful" {
+			t.Errorf("expected system prompt, got %v", req["system"])
+		}
+		msgs := req["messages"].([]interface{})
+		if len(msgs) != 1 {
+			t.Errorf("expected 1 user message, got %d", len(msgs))
+		}
+		if req["max_tokens"] != float64(8192) {
+			t.Errorf("expected max_tokens 8192, got %v", req["max_tokens"])
+		}
+
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"content":[{"type":"text","text":"Hello from Claude!"}]}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-key", "claude-sonnet").WithProvider(ProviderAnthropic)
+	got, err := client.Complete(context.Background(), []Message{
+		{Role: "system", Content: "You are helpful"},
+		{Role: "user", Content: "Hi"},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got != "Hello from Claude!" {
+		t.Errorf("expected %q, got %q", "Hello from Claude!", got)
+	}
+}
+
+func TestComplete_Anthropic_NoContent(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.Write([]byte(`{"content":[]}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-key", "claude-sonnet").WithProvider(ProviderAnthropic)
+	_, err := client.Complete(context.Background(), []Message{{Role: "user", Content: "Hi"}})
+	if err == nil {
+		t.Fatal("expected error for empty content, got nil")
+	}
+}
+
+func TestComplete_Anthropic_APIError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte(`{"error":{"message":"invalid request"}}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "test-key", "claude-sonnet").WithProvider(ProviderAnthropic)
+	_, err := client.Complete(context.Background(), []Message{{Role: "user", Content: "Hi"}})
+	if err == nil {
+		t.Fatal("expected error for 400, got nil")
+	}
+}
+
+func TestWithProvider(t *testing.T) {
+	client := NewClient("http://example.com", "key", "model")
+	if client.provider != ProviderOpenAI {
+		t.Errorf("expected default provider openai, got %s", client.provider)
+	}
+	result := client.WithProvider(ProviderAnthropic)
+	if result != client {
+		t.Error("WithProvider should return the same client for chaining")
+	}
+	if client.provider != ProviderAnthropic {
+		t.Errorf("expected provider anthropic, got %s", client.provider)
+	}
+}
+
+func TestComplete_RetryOnBodyReadError(t *testing.T) {
+	attempts := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			// First attempt: send headers then close connection abruptly
+			// Simulate by writing partial response and flushing with wrong Content-Length
+			w.Header().Set("Content-Length", "1000")
+			w.WriteHeader(http.StatusOK)
+			w.Write([]byte(`{"choices":[{"message":{"con`))
+			// The test HTTP server will close the connection after handler returns,
+			// but Content-Length mismatch means client gets fewer bytes than expected
+			return
+		}
+		// Second attempt: succeed
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(ChatResponse{
+			Choices: []struct {
+				Message struct {
+					Content string `json:"content"`
+				} `json:"message"`
+			}{{Message: struct {
+				Content string `json:"content"`
+			}{Content: "success"}}},
+		})
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "key", "model")
+	got, err := client.Complete(context.Background(), []Message{{Role: "user", Content: "Hi"}})
+	if err != nil {
+		t.Fatalf("expected retry to succeed, got error: %v", err)
+	}
+	if got != "success" {
+		t.Errorf("expected %q, got %q", "success", got)
+	}
+	if attempts != 2 {
+		t.Errorf("expected 2 attempts, got %d", attempts)
+	}
+}
+
+func TestComplete_ContentLengthMismatch(t *testing.T) {
+	attempts := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		if attempts == 1 {
+			// Claim Content-Length is larger than actual body
+			w.Header().Set("Content-Length", "500")
+			w.Header().Set("Content-Type", "application/json")
+			w.WriteHeader(http.StatusOK)
+			// Write less than 500 bytes
+			w.Write([]byte(`{"choices":[{"message":{"content":"partial"}}]}`))
+			return
+		}
+		// Second attempt succeeds
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(ChatResponse{
+			Choices: []struct {
+				Message struct {
+					Content string `json:"content"`
+				} `json:"message"`
+			}{{Message: struct {
+				Content string `json:"content"`
+			}{Content: "complete"}}},
+		})
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "key", "model")
+	got, err := client.Complete(context.Background(), []Message{{Role: "user", Content: "Hi"}})
+	if err != nil {
+		t.Fatalf("expected retry to succeed on content-length mismatch, got: %v", err)
+	}
+	if got != "complete" {
+		t.Errorf("expected %q, got %q", "complete", got)
+	}
+}
+
+func TestComplete_NoRetryOnAPIError(t *testing.T) {
+	attempts := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		attempts++
+		w.WriteHeader(http.StatusBadRequest)
+		w.Write([]byte(`{"error":"bad request"}`))
+	}))
+	defer server.Close()
+
+	client := NewClient(server.URL, "key", "model")
+	_, err := client.Complete(context.Background(), []Message{{Role: "user", Content: "Hi"}})
+	if err == nil {
+		t.Fatal("expected error for 400, got nil")
+	}
+	if attempts != 1 {
+		t.Errorf("should not retry on API errors, got %d attempts", attempts)
+	}
+}
+
+func TestIsRetryableError(t *testing.T) {
+	tests := []struct {
+		name     string
+		err      string
+		expected bool
+	}{
+		{"nil formatted", "", false},
+		{"read response error", "read response: unexpected EOF", true},
+		{"body length mismatch", "body length mismatch: Content-Length=1000, received=500", true},
+		{"API error", "LLM API error (status 400): bad request", false},
+		{"parse error", "parse response: unexpected end of JSON input", false},
+		{"request error", "LLM request: connection refused", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.err == "" {
+				if isRetryableError(nil) {
+					t.Error("nil error should not be retryable")
+				}
+				return
+			}
+			err := fmt.Errorf("%s", tt.err)
+			got := isRetryableError(err)
+			if got != tt.expected {
+				t.Errorf("isRetryableError(%q) = %v, want %v", tt.err, got, tt.expected)
+			}
+		})
+	}
+}

review/formatter.go

@@ -9,6 +9,11 @@ import (
 func FormatMarkdown(result *ReviewResult, reviewerName string) string {
 	var sb strings.Builder
 
+	if reviewerName != "" {
+		title := strings.ToUpper(reviewerName[:1]) + reviewerName[1:]
+		sb.WriteString(fmt.Sprintf("# %s Review\n\n", title))
+	}
+
 	sb.WriteString("## Summary\n\n")
 	sb.WriteString(result.Summary)
 	sb.WriteString("\n\n")
@@ -30,6 +35,8 @@ func FormatMarkdown(result *ReviewResult, reviewerName string) string {
 
 	if reviewerName != "" {
 		sb.WriteString(fmt.Sprintf("\n---\n*Review by %s*\n", reviewerName))
+		// Hidden sentinel for identifying this bot's reviews during cleanup
+		sb.WriteString(fmt.Sprintf("\n<!-- review-bot:%s -->\n", reviewerName))
 	}
 
 	return sb.String()

review/formatter_test.go

@@ -116,3 +116,46 @@ func TestGiteaEvent(t *testing.T) {
 		}
 	}
 }
+
+func TestFormatMarkdown_Sentinel(t *testing.T) {
+	result := &ReviewResult{
+		Verdict:        "APPROVE",
+		Summary:        "All good.",
+		Recommendation: "Merge it.",
+	}
+	output := FormatMarkdown(result, "security")
+	if !strings.Contains(output, "<!-- review-bot:security -->") {
+		t.Error("expected sentinel comment in output")
+	}
+
+	// Empty reviewer name should NOT have sentinel
+	output2 := FormatMarkdown(result, "")
+	if strings.Contains(output2, "<!-- review-bot") {
+		t.Error("should not contain sentinel when reviewer name is empty")
+	}
+}
+
+func TestFormatMarkdown_RoleTitle(t *testing.T) {
+	result := &ReviewResult{
+		Verdict:        "APPROVE",
+		Summary:        "All good.",
+		Recommendation: "Merge it.",
+	}
+
+	// With reviewer name: should have title header
+	output := FormatMarkdown(result, "security")
+	if !strings.Contains(output, "# Security Review\n") {
+		t.Error("expected '# Security Review' header when reviewer name is set")
+	}
+
+	output2 := FormatMarkdown(result, "gpt")
+	if !strings.Contains(output2, "# Gpt Review\n") {
+		t.Error("expected '# Gpt Review' header")
+	}
+
+	// Without reviewer name: no title header
+	output3 := FormatMarkdown(result, "")
+	if strings.Contains(output3, "# ") && strings.Contains(output3, " Review\n") {
+		t.Error("should not contain role title header when reviewer name is empty")
+	}
+}

review/parser.go

@@ -29,7 +29,19 @@ func ParseResponse(response string) (*ReviewResult, error) {
 
 	var result ReviewResult
 	if err := json.Unmarshal([]byte(cleaned), &result); err != nil {
-		return nil, fmt.Errorf("parse LLM response as JSON: %w\nRaw response: %s", err, response)
+		// LLMs sometimes produce JSON with unescaped quotes inside string values.
+		// Try to repair before giving up.
+		repaired := repairJSON(cleaned)
+		if err2 := json.Unmarshal([]byte(repaired), &result); err2 != nil {
+			// Include diagnostic info: lengths help identify truncation
+			rawLen := len(response)
+			cleanedLen := len(cleaned)
+			preview := cleaned
+			if len(preview) > 200 {
+				preview = preview[:100] + "..." + preview[len(preview)-100:]
+			}
+			return nil, fmt.Errorf("parse LLM response as JSON: %w\nRaw length: %d, cleaned length: %d\nCleaned preview: %s", err, rawLen, cleanedLen, preview)
+		}
 	}
 
 	// Validate verdict
@@ -74,3 +86,230 @@ func extractJSON(s string) string {
 	s = strings.TrimSpace(s)
 	return s
 }
+
+// repairJSON attempts to fix common LLM JSON issues:
+// - Unescaped double quotes inside string values
+//
+// Strategy: walk the JSON structurally. Object keys are parsed normally (LLMs
+// get those right). For string VALUES, we find all candidate closing quotes and
+// pick the LAST one that leaves valid JSON structure afterward — maximizing
+// string content, which is the correct bias for the "LLM put unescaped quotes
+// in a string value" failure mode.
+func repairJSON(s string) string {
+	runes := []rune(s)
+	var out strings.Builder
+	out.Grow(len(s) + 64)
+
+	i := 0
+	for i < len(runes) {
+		c := runes[i]
+
+		if c != '"' {
+			out.WriteRune(c)
+			i++
+			continue
+		}
+
+		// We hit an opening quote. Determine if this is a key or a value.
+		// Keys: the standard JSON parser in LLMs gets keys right, so we parse
+		// them normally (first unescaped quote closes).
+		// Values: may contain unescaped quotes — use the repair heuristic.
+		isValue := isValuePosition(runes, i)
+
+		if !isValue {
+			// Parse key/simple string normally
+			out.WriteRune('"')
+			i++
+			for i < len(runes) {
+				ch := runes[i]
+				if ch == '\\' && i+1 < len(runes) {
+					out.WriteRune(ch)
+					i++
+					out.WriteRune(runes[i])
+					i++
+					continue
+				}
+				if ch == '"' {
+					out.WriteRune('"')
+					i++
+					break
+				}
+				out.WriteRune(ch)
+				i++
+			}
+			continue
+		}
+
+		// Value string — find the correct close using last-valid-candidate heuristic
+		out.WriteRune('"')
+		i++
+
+		closeIdx := findClosingQuote(runes, i)
+
+		// Write everything between open and close, escaping interior quotes
+		for j := i; j < closeIdx; j++ {
+			ch := runes[j]
+			if ch == '\\' && j+1 < closeIdx {
+				// Already-escaped sequence — pass through
+				out.WriteRune(ch)
+				j++
+				out.WriteRune(runes[j])
+			} else if ch == '"' {
+				out.WriteRune('\\')
+				out.WriteRune('"')
+			} else {
+				out.WriteRune(ch)
+			}
+		}
+
+		// Write the closing quote
+		out.WriteRune('"')
+		i = closeIdx + 1
+	}
+
+	return out.String()
+}
+
+// isValuePosition determines if the quote at position i is opening a JSON value
+// string (as opposed to an object key). We only apply repair to values that
+// follow ':' since those are the free-text fields where LLMs produce unescaped
+// quotes. Array elements and keys are left alone (parsed normally).
+func isValuePosition(runes []rune, i int) bool {
+	// Look backward, skipping whitespace, for the preceding structural char
+	j := i - 1
+	for j >= 0 && (runes[j] == ' ' || runes[j] == '\t' || runes[j] == '\n' || runes[j] == '\r') {
+		j--
+	}
+	if j < 0 {
+		return false
+	}
+	// After ':' → definitely a value
+	return runes[j] == ':'
+}
+
+// findClosingQuote finds the index of the true closing quote for a JSON string
+// value starting at position start (the character after the opening quote).
+// It collects all unescaped quote candidates and returns the FIRST one that
+// produces valid JSON continuation (deeper lookahead verifies the next token).
+func findClosingQuote(runes []rune, start int) int {
+	// Collect all candidate positions for the closing quote.
+	var candidates []int
+	for j := start; j < len(runes); j++ {
+		if runes[j] == '\\' {
+			j++ // skip escaped character
+			continue
+		}
+		if runes[j] == '"' {
+			candidates = append(candidates, j)
+		}
+	}
+
+	if len(candidates) == 0 {
+		return len(runes)
+	}
+
+	if len(candidates) == 1 {
+		return candidates[0]
+	}
+
+	// Try candidates from FIRST to LAST. The correct closing quote is the
+	// earliest one that produces valid JSON structure after it (verified by
+	// deeper lookahead that checks the next token is a valid JSON start).
+	for _, idx := range candidates {
+		if isValidJSONAfterClose(runes, idx+1) {
+			return idx
+		}
+	}
+
+	// Fallback: return the last candidate
+	return candidates[len(candidates)-1]
+}
+
+// isValidJSONAfterClose checks whether the runes after a candidate closing quote
+// look like valid JSON continuation for a VALUE string. Since we only use this
+// for value positions, ':' is NOT a valid continuation (values are never keys).
+// Checks deeper structure to avoid being fooled by JSON-like content in strings.
+func isValidJSONAfterClose(runes []rune, pos int) bool {
+	j := pos
+	for j < len(runes) && (runes[j] == ' ' || runes[j] == '\t' || runes[j] == '\n' || runes[j] == '\r') {
+		j++
+	}
+
+	if j >= len(runes) {
+		return true
+	}
+
+	next := runes[j]
+	if next == '}' || next == ']' {
+		// Closing a container. Verify what follows the close is also valid:
+		// another structural char, comma, or EOF.
+		return isValidAfterContainerClose(runes, j+1)
+	}
+	if next == ',' {
+		// After comma, must be followed by a valid JSON token
+		j++
+		for j < len(runes) && (runes[j] == ' ' || runes[j] == '\t' || runes[j] == '\n' || runes[j] == '\r') {
+			j++
+		}
+		if j >= len(runes) {
+			return false // trailing comma with nothing after — invalid
+		}
+		return isJSONTokenStart(runes, j)
+	}
+	// ':' is NOT valid here — we're in a value position, not a key.
+	// Any other character is also invalid.
+	return false
+}
+
+// isValidAfterContainerClose checks that after a } or ], the continuation is
+// structurally valid: more closes, comma+token, or EOF.
+func isValidAfterContainerClose(runes []rune, pos int) bool {
+	j := pos
+	for j < len(runes) && (runes[j] == ' ' || runes[j] == '\t' || runes[j] == '\n' || runes[j] == '\r') {
+		j++
+	}
+	if j >= len(runes) {
+		return true
+	}
+	next := runes[j]
+	if next == '}' || next == ']' {
+		return isValidAfterContainerClose(runes, j+1)
+	}
+	if next == ',' {
+		j++
+		for j < len(runes) && (runes[j] == ' ' || runes[j] == '\t' || runes[j] == '\n' || runes[j] == '\r') {
+			j++
+		}
+		if j >= len(runes) {
+			return false
+		}
+		return isJSONTokenStart(runes, j)
+	}
+	return false
+}
+
+// isJSONTokenStart returns true if the rune could begin a JSON value or key.
+// For keywords (true/false/null), verifies the full keyword is present.
+func isJSONTokenStart(runes []rune, pos int) bool {
+	if pos >= len(runes) {
+		return false
+	}
+	r := runes[pos]
+	switch {
+	case r == '"': // string
+		return true
+	case r == '{' || r == '[': // object or array
+		return true
+	case r == 't': // true
+		return pos+4 <= len(runes) && string(runes[pos:pos+4]) == "true"
+	case r == 'f': // false
+		return pos+5 <= len(runes) && string(runes[pos:pos+5]) == "false"
+	case r == 'n': // null
+		return pos+4 <= len(runes) && string(runes[pos:pos+4]) == "null"
+	case r >= '0' && r <= '9': // number
+		return true
+	case r == '-': // negative number
+		return true
+	}
+	return false
+}

review/parser_test.go

@@ -1,6 +1,7 @@
 package review
 
 import (
+	"encoding/json"
 	"testing"
 )
 
@@ -112,3 +113,112 @@ func TestParseResponse_MarkdownFencesNoLang(t *testing.T) {
 		t.Errorf("expected APPROVE, got %q", result.Verdict)
 	}
 }
+
+func TestParseResponse_UnescapedQuotesInStrings(t *testing.T) {
+	// Real failure from CI: Sonnet puts unescaped quotes like (e.g. "28") in findings
+	input := `{"verdict": "APPROVE", "summary": "Clean PR", "findings": [{"severity": "NIT", "file": "ci/Dockerfile", "line": 14, "finding": "The comment says OTP_VERSION is the major version (e.g. \"28\") but it actually contains unescaped quotes like (e.g. "28") which breaks JSON"}], "recommendation": "Ship it"}`
+
+	result, err := ParseResponse(input)
+	if err != nil {
+		t.Fatalf("expected repair to handle unescaped quotes, got error: %v", err)
+	}
+	if result.Verdict != "APPROVE" {
+		t.Errorf("expected APPROVE, got %q", result.Verdict)
+	}
+	if len(result.Findings) != 1 {
+		t.Fatalf("expected 1 finding, got %d", len(result.Findings))
+	}
+}
+
+func TestRepairJSON_NoOpOnValid(t *testing.T) {
+	valid := `{"key": "value", "num": 42}`
+	result := repairJSON(valid)
+	if result != valid {
+		t.Errorf("repairJSON should not modify valid JSON\n  got:  %s\n  want: %s", result, valid)
+	}
+}
+
+func TestRepairJSON_FixesUnescapedQuotes(t *testing.T) {
+	// Interior quote followed by non-structural character
+	input := `{"msg": "use "foo" here"}`
+	result := repairJSON(input)
+
+	// Should be parseable now
+	var m map[string]interface{}
+	if err := json.Unmarshal([]byte(result), &m); err != nil {
+		t.Fatalf("repaired JSON should parse, got: %v\nrepaired: %s", err, result)
+	}
+}
+
+func TestRepairJSON_InteriorQuoteBeforeComma(t *testing.T) {
+	// Bug reported by reviewer: interior quoted word immediately before a comma
+	input := `{"msg": "say "yes", and go"}`
+	result := repairJSON(input)
+
+	var m map[string]interface{}
+	if err := json.Unmarshal([]byte(result), &m); err != nil {
+		t.Fatalf("repaired JSON should parse, got: %v\nrepaired: %s", err, result)
+	}
+	// The full string content should be preserved
+	msg, ok := m["msg"].(string)
+	if !ok {
+		t.Fatal("msg field missing or not a string")
+	}
+	if msg != `say "yes", and go` {
+		t.Errorf("unexpected msg content: %q", msg)
+	}
+}
+
+func TestRepairJSON_InteriorQuoteBeforeCloseBrace(t *testing.T) {
+	// Bug reported by reviewer: JSON-shaped syntax inside string values
+	input := `{"msg": "input map {"key": "val"} caused error"}`
+	result := repairJSON(input)
+
+	var m map[string]interface{}
+	if err := json.Unmarshal([]byte(result), &m); err != nil {
+		t.Fatalf("repaired JSON should parse, got: %v\nrepaired: %s", err, result)
+	}
+}
+
+func TestRepairJSON_MultipleFields(t *testing.T) {
+	// Multiple string fields with unescaped quotes in different positions
+	input := `{"a": "hello "world"", "b": "foo"}`
+	result := repairJSON(input)
+
+	var m map[string]interface{}
+	if err := json.Unmarshal([]byte(result), &m); err != nil {
+		t.Fatalf("repaired JSON should parse, got: %v\nrepaired: %s", err, result)
+	}
+	if _, ok := m["b"]; !ok {
+		t.Error("expected 'b' field to be preserved")
+	}
+}
+
+func TestRepairJSON_PreservesEscapedQuotes(t *testing.T) {
+	// Already-escaped quotes should not be double-escaped
+	input := `{"msg": "already \"escaped\" here"}`
+	result := repairJSON(input)
+
+	if result != input {
+		t.Errorf("repairJSON should not modify already-escaped quotes\n  got:  %s\n  want: %s", result, input)
+	}
+
+	var m map[string]interface{}
+	if err := json.Unmarshal([]byte(result), &m); err != nil {
+		t.Fatalf("repaired JSON should parse, got: %v\nrepaired: %s", err, result)
+	}
+}
+
+func TestRepairJSON_ComplexNestedContent(t *testing.T) {
+	// Combines both reviewer bugs: quoted words before commas AND JSON-like content
+	input := `{"verdict": "APPROVE", "findings": [{"finding": "The map {"key": "val"} and (e.g. "28") and say "yes", then stop"}]}`
+	result := repairJSON(input)
+
+	var parsed map[string]interface{}
+	if err := json.Unmarshal([]byte(result), &parsed); err != nil {
+		t.Fatalf("repaired JSON should parse, got: %v\nrepaired: %s", err, result)
+	}
+	if parsed["verdict"] != "APPROVE" {
+		t.Errorf("expected verdict APPROVE, got %v", parsed["verdict"])
+	}
+}

review/prompt.go

@@ -1,3 +1,5 @@
+// Package review builds prompts for AI code review and parses LLM responses
+// into structured review results.
 package review
 
 import (
@@ -5,8 +7,10 @@ import (
 	"strings"
 )
 
-// BuildSystemPrompt constructs the system prompt for the LLM reviewer.
+// BuildSystemBase returns the core system prompt instructions without
-func BuildSystemPrompt(conventions, patterns string) string {
+// patterns or conventions. Used by the budget package to separate
+// trimmable from non-trimmable content.
+func BuildSystemBase() string {
 	var sb strings.Builder
 
 	sb.WriteString("You are an expert code reviewer. Review the provided pull request diff carefully.\n\n")
@@ -40,6 +44,15 @@ func BuildSystemPrompt(conventions, patterns string) string {
 	sb.WriteString("- Line numbers should reference the new file line numbers from the diff headers.\n")
 	sb.WriteString("- If the diff is empty or trivial (only formatting/whitespace), APPROVE with no findings.\n")
 
+	return sb.String()
+}
+
+// BuildSystemPrompt constructs the full system prompt with patterns and conventions.
+// Deprecated: Use BuildSystemBase with budget.Fit for context-aware assembly.
+func BuildSystemPrompt(conventions, patterns string) string {
+	var sb strings.Builder
+	sb.WriteString(BuildSystemBase())
+
 	if patterns != "" {
 		sb.WriteString(fmt.Sprintf("\n\n## Language Patterns & Idioms\n\nUse the following patterns as review criteria. Code that violates these established patterns is a finding:\n\n%s\n", patterns))
 	}
@@ -51,8 +64,9 @@ func BuildSystemPrompt(conventions, patterns string) string {
 	return sb.String()
 }
 
-// BuildUserPrompt constructs the user message with PR context.
+// BuildUserMeta returns the PR metadata header (title, description, CI status)
-func BuildUserPrompt(title, description, diff, fileContext string, ciPassed bool, ciDetails string) string {
+// without the diff or file context. Used by the budget package.
+func BuildUserMeta(title, description string, ciPassed bool, ciDetails string) string {
 	var sb strings.Builder
 
 	sb.WriteString(fmt.Sprintf("## Pull Request: %s\n\n", title))
@@ -71,6 +85,16 @@ func BuildUserPrompt(title, description, diff, fileContext string, ciPassed bool
 		sb.WriteString(fmt.Sprintf("CI Details: %s\n", ciDetails))
 	}
 
+	return sb.String()
+}
+
+// BuildUserPrompt constructs the user message with PR context.
+// Deprecated: Use BuildUserMeta with budget.Fit for context-aware assembly.
+func BuildUserPrompt(title, description, diff, fileContext string, ciPassed bool, ciDetails string) string {
+	var sb strings.Builder
+
+	sb.WriteString(BuildUserMeta(title, description, ciPassed, ciDetails))
+
 	if fileContext != "" {
 		sb.WriteString("\n### Full File Context (modified files)\n\n")
 		sb.WriteString(fileContext)

review/prompt_test.go

@@ -116,3 +116,43 @@ func TestBuildUserPrompt_WithoutFileContext(t *testing.T) {
 		t.Error("should not include file context section when empty")
 	}
 }
+
+
+func TestBuildSystemBase(t *testing.T) {
+	result := BuildSystemBase()
+	if result == "" {
+		t.Fatal("BuildSystemBase returned empty string")
+	}
+	if !strings.Contains(result, "expert code reviewer") {
+		t.Error("expected reviewer role in system base")
+	}
+	if !strings.Contains(result, "REQUEST_CHANGES") {
+		t.Error("expected verdict format in system base")
+	}
+	if !strings.Contains(result, "JSON") {
+		t.Error("expected JSON output instruction in system base")
+	}
+}
+
+func TestBuildUserMeta(t *testing.T) {
+	result := BuildUserMeta("Fix bug", "Some description", true, "all checks passed")
+	if !strings.Contains(result, "Fix bug") {
+		t.Error("expected title in user meta")
+	}
+	if !strings.Contains(result, "Some description") {
+		t.Error("expected description in user meta")
+	}
+	if !strings.Contains(result, "PASSED") {
+		t.Error("expected CI PASSED status")
+	}
+}
+
+func TestBuildUserMeta_CIFailed(t *testing.T) {
+	result := BuildUserMeta("Title", "", false, "test job failed")
+	if !strings.Contains(result, "FAILED") {
+		t.Error("expected CI FAILED status")
+	}
+	if strings.Contains(result, "Description") {
+		t.Error("expected no description section when empty")
+	}
+}