MCP Server: Committy Wrapper

A Node.js/TypeScript MCP server that wraps the Rust committy CLI to provide conventional-commit linting and release tooling via MCP tools.

Requirements

• Node.js 18+
• Rust committy CLI installed and available as committy in PATH, or set COMMITTY_BIN to its absolute path.

Install / Build

# In mcp-server-committy/
npm ci
npm run build

Development

# Start in watch mode (stdio server)
npm run dev

This starts an MCP stdio server and waits for an MCP client to connect.

Local CLI (npm link)

You can link the package locally to get the CLI binary in your PATH:

# In mcp-server-committy/
npm link
 
# Now you can run the stdio MCP server directly
mcp-server-committy

Note: This is a stdio server intended to be started by an MCP client.

Run (built)

# After build
npm start
# or
node dist/index.js

If the committy binary is not available, set:

export COMMITTY_BIN=/absolute/path/to/committy

Tools

• mcp0_lint_repo_since_last_tag

  • Input: { repo_path: string }
  • Lints repository commits since the last tag.

• mcp0_lint_message

  • Input: { message: string }
  • Lints a single commit message.

• mcp0_compute_next_tag

  • Input: { repo_path: string, fetch?: boolean, prerelease?: boolean, prerelease_suffix?: string, release_branches?: string[] }
  • Computes the next tag without mutating the repo.

• mcp0_apply_tag

  • Input: { repo_path: string, name?: string, fetch?: boolean, prerelease?: boolean, prerelease_suffix?: string, release_branches?: string[], bump_files?: boolean, tag_message?: string, confirm_push: boolean }
  • Creates/pushes a tag. Refuses unless confirm_push is true.

• mcp0_format_message

  • Input: { commit_type: string, short: string, scope?: string, long?: string, breaking?: boolean }
  • Returns a conventional commit message from parts.

• mcp0_generate_guidelines

  • Input: { repo_path: string, additional_files?: string[], max_bytes?: number }
  • Reads README.md, CONTRIBUTING.md, and changelog config if present.

• mcp0_commit_grouped_changes

  • Input: { repo_path: string, dry_run?: boolean, include_unstaged?: boolean, auto_stage?: boolean, push?: boolean, signoff?: boolean, confirm?: boolean, group_overrides?: { [group]: { commit_type?: string, scope?: string, short?: string, long?: string } } }
  • Analyzes pending changes, groups by kind (docs/tests/ci/deps/build/chore/code), returns a plan with suggested conventional commit messages. When confirm=true (and dry_run=false), stages per group and creates one commit per group. If push=true, pushes after committing.

• mcp0_group_commit_plan

  • Input: { repo_path: string, include_unstaged?: boolean, ai?: boolean, ai_provider?: "openrouter"|"ollama", ai_model?: string, ai_api_key_env?: string, ai_base_url?: string, ai_max_tokens?: number, ai_temperature?: number, ai_timeout_ms?: number, no_ai_json_mode?: boolean, ai_system_prompt?: string, ai_system_prompt_file?: string, ai_file_limit?: number, ai_allow_sensitive?: boolean }
  • Wraps Rust committy group-commit --mode plan --output json. Returns { command: "group-commit", mode: "plan", ok, groups, errors? }.

• mcp0_group_commit_apply

  • Input: { repo_path: string, include_unstaged?: boolean, auto_stage?: boolean, push?: boolean, ai?: boolean, ai_provider?: "openrouter"|"ollama", ai_model?: string, ai_api_key_env?: string, ai_base_url?: string, ai_max_tokens?: number, ai_temperature?: number, ai_timeout_ms?: number, no_ai_json_mode?: boolean, ai_system_prompt?: string, ai_system_prompt_file?: string, ai_file_limit?: number, ai_allow_sensitive?: boolean }
  • Wraps Rust committy group-commit --mode apply --output json and returns { command: "group-commit", mode: "apply", ok, groups, commits, pushed?, errors? }.

Testing

A simple Node-based test script validates behavior without extra deps:

npm test

This checks:

• formatMessage() formatting
• Friendly error when committy binary is missing
• generateGuidelines() reads common repo files
• computeNextTag() and applyTag() success flows using a fake CLI script
• groupCommitPlan() and groupCommitApply() success flows using a fake CLI script

For internal tests, a fake CLI is used by setting:

export COMMITTY_BIN=node
export COMMITTY_SCRIPT=$(pwd)/scripts/fake-committy.mjs

AI flags & security

• These tools pass AI-related inputs through to the Rust CLI. See group-commit flags in the Rust README.
• Key options: ai, ai_provider, ai_model, ai_api_key_env, ai_base_url, ai_max_tokens, ai_temperature, ai_timeout_ms, no_ai_json_mode, ai_system_prompt, ai_system_prompt_file, ai_file_limit, ai_allow_sensitive.
• Security: by default, sensitive file contents are not sent. Set ai_allow_sensitive=true only if you understand the risks.
• API keys: provide via environment variable named by ai_api_key_env on the MCP server process.

Notes

• Returns tool outputs as text (JSON string) to conform with the SDK content types.
• CLI binary name: mcp-server-committy (after npm link).