This report presents the forensic synthetic code analysis of anthropics/claude-code-action, a TypeScript project with 8,351 GitHub stars. SynthScan v2.0 examined 36,041 lines of code across 184 source files, recording 69 pattern matches distributed across 13 syntactic categories. The overall adjusted score of 3.1 places this repository in the Likely human-written band.
The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).
This chart maps the temporal evolution of the adjusted synthetic code score across successive scan runs. An upward trajectory indicates ongoing incorporation of AI-generated code or expanding LLM-assisted scaffolding; a stable or declining trajectory may reflect active human refactoring, code removal, or the adoption of stricter authorship policies. The dashed secondary line (right axis) independently tracks total raw pattern hit count, which can diverge from the normalised score when codebase size changes significantly between scans.
Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.
This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.
The scanner identified 69 distinct pattern matches across 13 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.
Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | agent-approval-check/agent_approval_check.py | 693 | def get_latest_review_per_user(reviews: list[dict]) -> dict[str, dict]: | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 799 | def load_agent_config_from_env(repo: str) -> AgentConfig: | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 979 | def collect_approval_reactions( | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 1034 | def find_notification_comment(comments: list[dict]) -> dict | None: | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 1041 | def find_stale_notification_for_commit( | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 1052 | def find_old_stale_notifications(comments: list[dict], latest_sha: str) -> list[dict]: | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 1062 | def generate_notification_comment( | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 1144 | def generate_stale_notification(stale_approvals: list[dict], latest_sha: str) -> str: | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 1545 | def format_status_description(message: str, head_sha: str) -> str: | CODE |
| LOW | test/restore-config.test.ts | 226 | function countClaudePrExcludeEntries(): number { | CODE |
| LOW | base-action/src/workload-identity.ts | 42 | export function isWorkloadIdentityConfigured(): boolean { | CODE |
| LOW | base-action/src/parse-sdk-options.ts | 133 | function parseClaudeArgsToExtraArgs( | CODE |
| LOW | base-action/src/prepare-prompt.ts | 14 | async function validateAndPreparePrompt( | CODE |
| LOW | base-action/src/prepare-prompt.ts | 62 | async function createTemporaryPromptFile( | CODE |
| LOW | base-action/src/validate-env.ts | 5 | export function validateEnvironmentVariables() { | CODE |
| LOW | base-action/src/execution-file.ts | 34 | export function setExecutionFileOutputIfPresent(): string | undefined { | CODE |
| LOW | src/modes/detector.ts | 83 | function validateTrackProgressEvent(context: GitHubContext): void { | CODE |
| LOW | src/mcp/install-mcp-server.ts | 20 | async function checkActionsReadPermission( | CODE |
| LOW | src/mcp/github-file-ops-server.ts | 58 | async function getOrCreateBranchRef( | CODE |
| LOW | src/create-prompt/index.ts | 79 | export function buildDisallowedToolsString( | CODE |
| LOW | src/create-prompt/index.ts | 896 | function extractUserRequestFromContext( | CODE |
| LOW | src/github/context.ts | 279 | export function isPullRequestReviewCommentEvent( | CODE |
| LOW | src/github/token.ts | 28 | function getAppTokenExchangeErrorMessage( | CODE |
| LOW | src/github/token.ts | 34 | function isWorkflowValidationError( | CODE |
| LOW | src/github/token.ts | 75 | export function parseAdditionalPermissions(): | CODE |
| LOW | src/github/utils/actor-filter.ts | 39 | export function shouldIncludeCommentByActor( | CODE |
| LOW | src/github/utils/sanitizer.ts | 12 | export function stripMarkdownImageAltText(content: string): string { | CODE |
| LOW | src/github/utils/image-downloader.ts | 263 | function detectImageExtensionFromBuffer(buffer: Buffer): string | undefined { | CODE |
| LOW | src/github/operations/restore-config.ts | 48 | function ensureClaudePrExcludedFromGit(): void { | CODE |
| LOW | src/github/operations/branch-cleanup.ts | 5 | export async function checkAndCommitOrDeleteBranch( | CODE |
| LOW | src/github/data/formatter.ts | 144 | export function formatChangedFilesWithSHA( | CODE |
| LOW | src/entrypoints/collect-inputs.ts | 1 | export function collectActionInputsPresence(): string { | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | CONTRIBUTING.md | 31 | export ANTHROPIC_API_KEY="your-api-key-here" | CODE |
| HIGH | base-action/README.md | 326 | "API_KEY": "your-api-key" | CODE |
| HIGH | base-action/README.md | 344 | "API_KEY": "your-api-key" | CODE |
| HIGH | base-action/CONTRIBUTING.md | 31 | export ANTHROPIC_API_KEY="your-api-key-here" | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| HIGH | test/validate-branch-name.test.ts | 49 | it("should accept branch names containing + (generated by Claude Code EnterWorktree)", () => { | CODE |
| HIGH | base-action/README.md | 438 | body: "## Claude Code Review\n\n" + review + "\n\n*Generated by Claude Code*" | CODE |
| HIGH | src/github/operations/branch.ts | 64 | // + is valid per git-check-ref-format and generated by Claude Code's EnterWorktree tool when | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | bunfig.toml | 1 | # Intentionally minimal. action.yml pins --config to this file so bun resolves | COMMENT |
| LOW | agent-approval-check/agent_approval_check.py | 1381 | logger.warning("PR has >100 changed files - cannot verify all file paths") | COMMENT |
| LOW | docs/usage.md | 21 | - uses: anthropics/claude-code-action@v1 | COMMENT |
| LOW | docs/usage.md | 41 | # trigger_phrase: "/claude" | COMMENT |
| LOW | examples/claude.yml | 41 | COMMENT | |
| LOW | examples/claude-wif.yml | 41 | uses: anthropics/claude-code-action@v1 | COMMENT |
| LOW | examples/ci-failure-auto-fix.yml | 1 | name: Auto Fix CI Failures | COMMENT |
| LOW | .github/workflows/release.yml | 121 | git tag -fa "$major_version" -m "Update $major_version tag to $next_version" | COMMENT |
| LOW | .github/workflows/release.yml | 141 | # next_version="${{ needs.create-release.outputs.next_version }}" | COMMENT |
| LOW | .github/workflows/release.yml | 161 | # gh release create "$next_version" \ | COMMENT |
| LOW | src/github/operations/branch.ts | 61 | COMMENT | |
| LOW | src/entrypoints/run.ts | 241 | // When workload identity federation is configured, fetch the GitHub OIDC | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | base-action/test-mcp-local.sh | 9 | # Check if ANTHROPIC_API_KEY is set | COMMENT |
| LOW | .github/workflows/test-mcp-servers.yml | 59 | # Check if mcp_servers field exists in the init event | COMMENT |
| LOW | .github/workflows/test-mcp-servers.yml | 153 | # Check if mcp_servers field exists in the init event | COMMENT |
| LOW | .github/workflows/test-settings.yml | 58 | # Check if the echo command worked | COMMENT |
| LOW | .github/workflows/test-settings.yml | 148 | # Check if the echo command worked | COMMENT |
| LOW | .github/workflows/sync-base-action.yml | 65 | # Check if there are any changes | COMMENT |
| LOW | .github/workflows/test-structured-output.yml | 303 | # Check if all passed | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | .github/workflows/release.yml | 146 | # # Create the version tag | COMMENT |
| MEDIUM | .github/workflows/release.yml | 160 | # # Create the release | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | examples/pr-review-comprehensive.yml | 66 | # Tools for comprehensive PR review | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | scripts/gh.sh | 7 | # Usage: | COMMENT |
| LOW | scripts/git-push.sh | 9 | # Usage: | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | agent-approval-check/agent_approval_check.py | 98 | logger = logging.getLogger(__name__) | CODE |
| LOW | agent-approval-check/agent_approval_check.py | 376 | def update_comment(self, alias: str, node_id: str, body: str) -> None: | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| MEDIUM | src/create-prompt/index.ts | 864 | "I'm unable to [specific action] due to [reason]. You can find more information and potential workarounds in the [FAQ](h | CODE |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | src/entrypoints/prepare.ts | 36 | // Step 3: Check write permissions (only for entity contexts) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | src/entrypoints/prepare.ts | 36 | // Step 3: Check write permissions (only for entity contexts) | COMMENT |
| Severity | File | Line | Snippet | Context |
|---|---|---|---|---|
| LOW | test/create-prompt.test.ts | 40 | name: "John Doe", | CODE |