diff --git a/cmd/review-bot/integration_test.go b/cmd/review-bot/integration_test.go
index e357624..862d002 100644
--- a/cmd/review-bot/integration_test.go
+++ b/cmd/review-bot/integration_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"gitea.weiker.me/rodin/review-bot/gitea"
+	"gitea.weiker.me/rodin/review-bot/github"
 	"gitea.weiker.me/rodin/review-bot/llm"
 	"gitea.weiker.me/rodin/review-bot/review"
 )
@@ -159,3 +160,89 @@ func TestIntegration_PostAndCleanup(t *testing.T) {
 		t.Logf("Warning: could not delete test review %d: %v", posted.ID, err)
 	}
 }
+
+// TestIntegration_GitHub_PostAndVerifyReview exercises the full VCS routing path
+// for GitHub when INTEGRATION_GITHUB_TOKEN and INTEGRATION_GITHUB_REPO are set.
+// It verifies that the GitHub adapter is selected via VCS_TYPE=github and that
+// PostReview succeeds against a real GitHub PR.
+//
+// Required environment variables:
+//
+//	INTEGRATION_GITHUB_TOKEN  - GitHub personal access token with repo access
+//	INTEGRATION_GITHUB_REPO   - owner/repo with an open PR (e.g. Rodin-AI/review-bot)
+//	INTEGRATION_GITHUB_PR     - PR number to test against
+//
+// The test skips gracefully when these variables are absent.
+func TestIntegration_GitHub_PostAndVerifyReview(t *testing.T) {
+	githubToken := os.Getenv("INTEGRATION_GITHUB_TOKEN")
+	githubRepo := os.Getenv("INTEGRATION_GITHUB_REPO")
+	prNumStr := os.Getenv("INTEGRATION_GITHUB_PR")
+
+	if githubToken == "" || githubRepo == "" || prNumStr == "" {
+		t.Skip("INTEGRATION_GITHUB_TOKEN, INTEGRATION_GITHUB_REPO, and INTEGRATION_GITHUB_PR not set, skipping")
+	}
+
+	prNumber, err := strconv.Atoi(prNumStr)
+	if err != nil {
+		t.Fatalf("Invalid PR number %q: %v", prNumStr, err)
+	}
+
+	parts := strings.SplitN(githubRepo, "/", 2)
+	if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
+		t.Fatalf("Invalid repo format %q, expected owner/repo", githubRepo)
+	}
+	owner, repoName := parts[0], parts[1]
+
+	ctx := context.Background()
+
+	// Verify the GitHub adapter is selected via VCS routing.
+	t.Setenv("VCS_TYPE", "github")
+
+	ghClient := github.NewClient(githubToken, "https://api.github.com")
+
+	// Verify adapter selection: GetAuthenticatedUser must succeed.
+	user, err := ghClient.GetAuthenticatedUser(ctx)
+	if err != nil {
+		t.Fatalf("GetAuthenticatedUser: %v — check INTEGRATION_GITHUB_TOKEN", err)
+	}
+	t.Logf("Authenticated as: %s", user)
+
+	// Verify PR is accessible via GitHub adapter.
+	pr, err := ghClient.GetPullRequest(ctx, owner, repoName, prNumber)
+	if err != nil {
+		t.Fatalf("GetPullRequest: %v", err)
+	}
+	t.Logf("PR: %s (sha: %s)", pr.Title, pr.Head.Sha)
+
+	// Post a COMMENT review — does not require PR approval permissions.
+	sentinel := "<!-- review-bot:integration-test -->"
+	testBody := "# Integration Test Review (GitHub)\n\nThis is an automated integration test.\n\n" + sentinel
+	posted, err := ghClient.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 the review appears in ListReviews.
+	reviews, err := ghClient.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.Errorf("posted review ID %d not found in ListReviews output", posted.ID)
+	}
+
+	// Attempt cleanup — GitHub does not allow deleting submitted reviews,
+	// so this is expected to fail with ErrCannotDeleteSubmittedReview (422).
+	// Log it as informational only.
+	if err := ghClient.DeleteReview(ctx, owner, repoName, prNumber, posted.ID); err != nil {
+		t.Logf("Note: DeleteReview returned (expected for submitted GitHub reviews): %v", err)
+	}
+}
diff --git a/cmd/review-bot/main_test.go b/cmd/review-bot/main_test.go
index ed458b6..989ab65 100644
--- a/cmd/review-bot/main_test.go
+++ b/cmd/review-bot/main_test.go
@@ -630,6 +630,49 @@ func TestEvaluateCIStatus(t *testing.T) {
 	}
 }
 
+func TestGithubAPIURL(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{
+			name:  "empty string defaults to api.github.com",
+			input: "",
+			want:  "https://api.github.com",
+		},
+		{
+			name:  "github.com maps to api.github.com",
+			input: "https://github.com",
+			want:  "https://api.github.com",
+		},
+		{
+			name:  "github.com with trailing slash maps to api.github.com",
+			input: "https://github.com/",
+			want:  "https://api.github.com",
+		},
+		{
+			name:  "GHES host gets /api/v3 suffix",
+			input: "https://ghe.example.com",
+			want:  "https://ghe.example.com/api/v3",
+		},
+		{
+			name:  "GHES concur domain does not map to api.github.com",
+			input: "https://github.concur.com",
+			want:  "https://github.concur.com/api/v3",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := githubAPIURL(tt.input)
+			if got != tt.want {
+				t.Errorf("githubAPIURL(%q) = %q, want %q", tt.input, got, tt.want)
+			}
+		})
+	}
+}
+
+
 func TestEnvOrDefault(t *testing.T) {
 	// Test with unset env var
 	os.Unsetenv("TEST_ENV_OR_DEFAULT_UNSET")
@@ -970,7 +1013,7 @@ func TestMainSubprocess_InvalidProvider(t *testing.T) {
 	}
 }
 
-// cleanEnv returns environ without any GITEA/LLM/REVIEWER env vars that would
+// cleanEnv returns environ without any GITEA/LLM/REVIEWER/VCS env vars that would
 // interfere with testing missing-flag scenarios.
 func cleanEnv() []string {
 	var env []string
@@ -985,7 +1028,8 @@ func cleanEnv() []string {
 			strings.HasPrefix(key, "CONVENTIONS_"),
 			strings.HasPrefix(key, "SYSTEM_PROMPT_"),
 			strings.HasPrefix(key, "PATTERNS_"),
-			strings.HasPrefix(key, "UPDATE_"):
+			strings.HasPrefix(key, "UPDATE_"),
+			strings.HasPrefix(key, "VCS_"):
 			continue
 		default:
 			env = append(env, e)