auto-commit-rs

Minimal CLI tool that generates git commit messages via LLMs.

Fast, lightweight, cross-platform. No runtime dependencies — just a single binary.

⚠️ Disclaimer: AI Generation and Code Quality

Please note that the majority of the code in this repository was generated by agentic AI. To ensure the quality and stability of the project, the following workflows are strictly enforced:

• Human Oversight: An AI agent does not commit code blindly. Every pull request, architecture decision, and code block generated by the AI is carefully reviewed and refined by a human developer.
• Unit Testing: The codebase is supported by comprehensive unit tests. We rely on standard CI/CD practices and test coverage to verify that the AI-generated logic performs exactly as expected.
• Use at Your Own Risk: While we strive for high code quality through testing and review, this software is provided "as is," without warranty of any kind.

Why Rust?

Tools like opencommit do the same thing but require Node.js and weigh in at ~100MB of node_modules. cgen is a single ~2MB static binary. No runtimes, no interpreters, no package managers — download and run.

Install

Linux / macOS (curl)

curl -fsSL https://raw.githubusercontent.com/gtkacz/auto-commit-rs/main/scripts/install.sh | bash

This detects your OS and architecture, downloads the latest release binary to /usr/local/bin, and makes it executable. Set INSTALL_DIR to change the target:

INSTALL_DIR=~/.local/bin curl -fsSL https://raw.githubusercontent.com/gtkacz/auto-commit-rs/main/scripts/install.sh | bash

Windows (PowerShell)

irm https://raw.githubusercontent.com/gtkacz/auto-commit-rs/main/scripts/install.ps1 | iex

This downloads the latest release to %LOCALAPPDATA%\cgen\ and adds it to your user PATH.

Cargo

From crates.io:

cargo install auto-commit-rs

From git:

cargo install --git https://github.com/gtkacz/auto-commit-rs

Manual Download

Grab a binary from the Releases page and place it somewhere in your PATH.

Available binaries:

• cgen-linux-amd64 — Linux x86_64
• cgen-macos-amd64 — macOS Intel
• cgen-macos-arm64 — macOS Apple Silicon
• cgen-windows-amd64.exe — Windows x86_64

Quick Start

# 1. Set your API key (one-time)
cgen config
# or: export ACR_API_KEY=your-key-here

# 2. Stage files and generate commit
git add .
cgen

Usage

cgen                    # Generate commit message and commit
cgen --dry-run          # Generate and show message without committing
cgen --verbose          # Print final system prompt used for LLM call (diff omitted)
cgen --tag              # Create next semantic version tag after commit
cgen --no-verify        # Forward flags to git commit
cgen alter <hash>       # Regenerate message from that commit's diff and rewrite it
cgen alter <old> <new>  # Use old..new net diff, rewrite <new> message
cgen undo               # Undo latest commit with safety prompts (soft reset)
cgen update             # Update cgen to the latest version
cgen config             # Interactive config editor (auto-detects scope)
cgen prompt             # Print the LLM system prompt without running anything

Any arguments passed to cgen (without a subcommand) are forwarded directly to git commit.

Configuration

All settings use the ACR_ prefix. Layered resolution: defaults → global TOML → local .env → env vars.

Config Locations

• Global: ~/.config/cgen/config.toml (Linux), ~/Library/Application Support/cgen/config.toml (macOS), %APPDATA%\cgen\config.toml (Windows)
• Local: .env in git repo root

Variable Interpolation

ACR_API_URL and ACR_API_HEADERS support $VARIABLE interpolation from environment variables:

ACR_API_URL=https://api.example.com/v1/$ACR_MODEL/chat
ACR_API_HEADERS=Authorization: Bearer $ACR_API_KEY, X-Custom: $MY_HEADER

Safety and Workflow Controls

• cgen now prints staged file count and names before generating a commit message.
• If staged files exceed ACR_WARN_STAGED_FILES_THRESHOLD and warnings are enabled, cgen asks for confirmation before continuing.
• cgen --dry-run generates and prints the final commit message but does not create a commit.
• cgen --verbose prints the final system prompt sent to the LLM and never prints diff payload.
• cgen prompt prints the full LLM system prompt (based on current config) without running any LLM call or git operations.
• cgen config auto-detects the context: inside a git repo it asks whether to edit local or global settings; outside a repo it opens the global config directly.
• cgen alter --dry-run generates and prints the rewritten message but does not rewrite history.
• cgen --tag creates a semantic version tag after a successful commit:
  • no existing tag -> 0.1.0
  • latest semver tag x.y.z -> x.(y+1).0
  • latest tag not in semantic versioning -> error
• If ACR_CONFIRM_NEW_VERSION=1, cgen asks before creating the computed tag; if 0, it creates it directly.
• cgen alter <old> <new> uses the old..new net diff as LLM input and rewrites only the <new> commit message.
• If cgen alter targets an already-pushed commit, cgen requires explicit confirmation before rewriting.
• After a real commit, push behavior follows ACR_POST_COMMIT_PUSH:
  • never: never push
  • ask: prompt whether to push (default)
  • always: push automatically
• For rewritten pushed history, cgen does not auto-force-push; use manual git push --force-with-lease if needed.
• cgen undo only undoes the latest commit (git reset --soft HEAD~1), never pushes, and warns before undoing pushed commits.

Updating

• cgen update checks for a newer version on GitHub and runs the appropriate installer:
  • If cargo is available: cargo install auto-commit-rs
  • Otherwise on Linux/macOS: re-runs the curl install script
  • Otherwise on Windows: re-runs the PowerShell install script
• On every run, cgen checks the latest GitHub release tag against the current version.
• The first time cgen runs, it asks whether to enable automatic updates and saves the preference to the global config.
• If ACR_AUTO_UPDATE=1, cgen automatically updates when a newer version is found.
• If ACR_AUTO_UPDATE=0 (or unset after the prompt), a warning is shown at the end of the output with the available version.

Providers

Built-in providers: Groq (default), OpenAI, Anthropic, Gemini.

For custom providers, set ACR_PROVIDER to any name and provide ACR_API_URL. Custom providers default to OpenAI-compatible request format.

export ACR_PROVIDER=ollama
export ACR_API_URL=http://localhost:11434/v1/chat/completions
export ACR_MODEL=llama3

Testing and Coverage

# Run all tests
cargo test --locked

# Enforce core logic coverage (matches CI gate)
cargo llvm-cov --locked --lib --tests \
  --ignore-filename-regex 'src/main.rs|src/cli.rs' \
  --summary-only \
  --fail-under-lines 95

Contributing

Contributions are welcome! Whether it's a new provider (often just 5 lines), a bug fix, or a documentation improvement — every bit helps.

See CONTRIBUTING.md for the full guide, including how to set up the development environment and how to add a new default provider step-by-step.

License

MIT