Claude Code Action is a GitHub Action that lets Claude answer questions, review code, and implement changes in pull requests and issues. Development teams use it through comments, assignments, or automated prompts, with execution on their own GitHub runners. The catalogue entries define agents, commands, integrations, and instructions for operating the action.
Borrowing it
Nothing to install: this file belongs to anthropics/claude-code-action. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/anthropics/claude-code-action/main/CLAUDE.mdgit clone --depth 1 https://github.com/anthropics/claude-code-actionWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/anthropics/claude-code-action/claude-md)<a href="https://agentmods.dev/instructions/anthropics/claude-code-action/claude-md"><img src="https://agentmods.dev/badge/instructions/anthropics/claude-code-action/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/anthropics/claude-code-action/claude-md"><img src="https://agentmods.dev/badge/instructions/anthropics/claude-code-action/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01339 | $0.01339 |
| Opus 5.5 | $0.00536 | $0.00536 |
| Sonnet 5.5 | $0.00268 | $0.00268 |
| Haiku 4.5 | $0.00134 | $0.00134 |
Grade A, and why
claude-code-action CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 19d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
Commands
bun test # Run tests
bun run typecheck # TypeScript type checking
bun run format # Format with prettier
bun run format:check # Check formatting
What This Is
A GitHub Action that lets Claude respond to @claude mentions on issues/PRs (tag mode) or run tasks via prompt input (agent mode). Mode is auto-detected: if prompt is provided, it's agent mode; if triggered by a comment/issue event with @claude, it's tag mode. See src/modes/detector.ts.
How It Runs
Single entrypoint: src/entrypoints/run.ts orchestrates everything — prepare (auth, permissions, trigger check, branch/comment creation), install Claude Code CLI, execute Claude via base-action/ functions (imported directly, not subprocess), then cleanup (update tracking comment, write step summary). SSH signing cleanup and token revocation are separate always() steps in action.yml.
base-action/ is also published standalone as @anthropic-ai/claude-code-base-action. Don't break its public API. It reads config from INPUT_-prefixed env vars (set by action.yml), not from action inputs directly.
Key Concepts
Auth priority: github_token input (user-provided) > GitHub App OIDC token (default). The claude_code_oauth_token and anthropic_api_key are for the Claude API, not GitHub. Token setup lives in src/github/token.ts.
Mode lifecycle: detectMode() in src/modes/detector.ts picks the mode name ("tag" or "agent"). Trigger checking and prepare dispatch are inlined in run.ts: tag mode calls prepareTagMode() from src/modes/tag/, agent mode calls prepareAgentMode() from src/modes/agent/.
Prompt construction: Tag mode's prepareTagMode() builds the prompt by fetching GitHub data (src/github/data/fetcher.ts), formatting it as markdown (src/github/data/formatter.ts), and writing it to a temp file via createPrompt(). Agent mode writes the user's prompt directly. The prompt includes issue/PR body, comments, diff, and CI status. This is the most important part of the action — it's what Claude sees.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 19d ago Changed · +14 lines · +499 tokens per session 283b44e8f01e
- 1mo ago First seen · 45 lines · 840 tokens per session scan A 02715cb8e2e4
claude-code-action CLAUDE.md is an instructions file published in the GitHub repository anthropics/claude-code-action (9,578 stars, last pushed today), licensed MIT. It adds 1,339 tokens to every session, about $0.0054 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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