commit-check MCP server

Catch bad commits before they merge — inside your AI agent.

Docs · Rules · CLI · GitHub Action · GitHub App

The Model Context Protocol server for Commit Check, commit policy as code for teams and AI agents. It gives your coding agent the rules your CI enforces: the agent validates its commit message, branch name and author before it commits or pushes, and when a correction is unambiguous it gets the fix to apply.

Quick start

claude mcp add commit-check -- uvx commit-check-mcp

Every other client launches the same command. This is the object to register:

{
  "mcpServers": {
    "commit-check": {
      "command": "uvx",
      "args": ["commit-check-mcp"]
    }
  }
}

No uv yet? curl -LsSf https://astral.sh/uv/install.sh | sh — or use pip install commit-check-mcp, as in the last row below.

Where each client keeps it

Client	Where it goes	Notes
Claude Code	claude mcp add commit-check -- uvx commit-check-mcp	Add --scope project to write a shareable .mcp.json at the repo root (--scope user makes it available in all your projects). You can also commit a .mcp.json containing the block above; "type": "stdio" may be added inside the server object. MCP servers are not configured in ~/.claude/settings.json.
Claude Desktop	macOS ~/Library/Application Support/Claude/claude_desktop_config.json; Windows %APPDATA%\Claude\claude_desktop_config.json	Block above as-is; restart Claude Desktop.
Cursor	project .cursor/mcp.json or global ~/.cursor/mcp.json	Block above as-is (or Settings → Cursor Settings → MCP → Add new MCP server with command uvx commit-check-mcp).
VS Code (Copilot agent mode)	.vscode/mcp.json	Different key: {"servers": {"commit-check": {"type": "stdio", "command": "uvx", "args": ["commit-check-mcp"]}}}
Cline	MCP Servers panel → Configure → cline_mcp_settings.json (check your client's docs)	Block above as-is.
Roo Code	project .roo/mcp.json or global mcp_settings.json (Edit Global MCP)	Block above as-is; optional "alwaysAllow": [...].
Windsurf	~/.codeium/windsurf/mcp_config.json (check your client's docs)	Block above as-is.
Continue	config.yaml (or a file in .continue/mcpServers/)	YAML list under mcpServers:, see below. Continue also picks up the JSON block above when dropped into .continue/mcpServers/.
Zed	~/.config/zed/settings.json	Different key: {"context_servers": {"commit-check": {"command": "uvx", "args": ["commit-check-mcp"]}}}
Anything else	your client's MCP config	If the client cannot run uvx: pip install commit-check-mcp, then set "command" to the absolute path of the installed binary and drop args. Find it with which commit-check-mcp (macOS/Linux), where commit-check-mcp (Windows cmd) or Get-Command commit-check-mcp | Select-Object -ExpandProperty Source (PowerShell).

Continue's config.yaml entry in full (name, version and schema are required by Continue; drop them if you are adding only the mcpServers fragment to an existing file, or save this as a standalone file in .continue/mcpServers/):

name: commit-check
version: 0.0.1
schema: v1
mcpServers:
  - name: commit-check
    command: uvx
    args: ["commit-check-mcp"]

Tools

Tool	What it checks	Arguments
validate_commit_message	A commit message: Conventional Commits, subject length and case, body, sign-off, WIP and fixup markers, AI attribution	message
validate_branch_name	A branch name, or the checked-out one, and its rebase target when configured	branch?
validate_author_info	Author name and email, and whether an AI tool is the author (CC017); read from the repository's git config when omitted	author_name? author_email?
validate_commit_context	Message, branch and author in one call, for whichever you pass	message? branch? author_name? author_email?
validate_push_safety	That a push is not a force push (CC301)	push_refs? — pre-push lines; omit to compare the branch with its upstream
validate_repository_state	The latest commit's message and author, the checked-out branch and, optionally, the push	include_message include_branch include_author (default true), include_push (default false)
describe_validation_rules	Nothing: returns the merged config and the rules it enables	—
server_health	Nothing: returns the server, commit-check and MCP SDK versions	—

Every tool but server_health also takes:

• repo_path — the repository whose cchk.toml / commit-check.toml applies. It must be a git repository when the tool reads git state; a plain directory holding a config file is enough when you pass every value yourself.
• config_path — a config file to use instead of the repository's own; relative paths resolve from repo_path.
• config — inline overrides merged on top, e.g. {"commit": {"require_body": true}}.

No tool changes the working tree or the commits. validate_push_safety and validate_repository_state may run git fetch to resolve a SHA, so only they are annotated as not read-only; a client that gates on MCP tool hints can auto-approve the other six.

Validate a message with the repository's rules:

{
  "message": "feat(api): add MCP validation tool",
  "repo_path": "/path/to/repo"
}

Check the repository as it stands, including the push:

{
  "repo_path": "/path/to/repo",
  "include_push": true
}

Validate push safety from git pre-push ref metadata (<local_ref> <local_sha> <remote_ref> <remote_sha>):

{
  "repo_path": "/path/to/repo",
  "push_refs": "refs/heads/main abc123 refs/heads/main def456"
}

See which rules apply once an override is merged in:

{
  "repo_path": "/path/to/repo",
  "config": {
    "commit": {
      "require_body": true
    }
  }
}

Results

Every validate_* tool returns the shape commit-check --format json prints:

{
  "status": "pass|fail|skip",
  "warnings": 0,
  "checks": [
    {
      "rule_id": "CC001",
      "check": "message",
      "status": "pass|fail|warn|skip",
      "value": "...",
      "error": "...",
      "suggest": "...",
      "fix": "...",
      "docs_url": "https://commit-check.com/rules/#cc001",
      "reason": ""
    }
  ]
}

• Only fail is a rejection. skip means nothing was validated — never read it as approval — and warn is reported without failing the run. With commit-check 2.19.0 or later, a skipped check names why in reason, e.g. "author dependabot[bot] is in [commit].ignore_authors"; older releases leave the field out.
• On fail, apply a non-empty fix verbatim, otherwise follow suggest, then validate again. The server's instructions teach the agent this loop.
• A call that cannot run at all — an empty message, a repo_path that does not exist or is not a git repository where one is needed, an invalid config, a push_refs SHA that cannot be resolved — comes back as an MCP tool error that names the problem, never as a pass.

Development

pip install -e .[dev]
python -m pytest

The server speaks stdio, so an MCP client launches it; run uvx commit-check-mcp by hand only to see that it starts.

Community

Questions and ideas go to Discussions, bugs to Issues. Releases follow Semantic Versioning. Released under the MIT License.

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mcp-name: io.github.commit-check/commit-check-mcp