Aptu is a context-engineering experiment: instead of throwing big models at problems, it crafts tight prompts that let smaller models do the job with fewer tokens and surprising precision.
Benchmarks
Head-to-head comparison of aptu+mercury-2 (Mercury 2, a small diffusion-based LLM by Inception Labs) vs a raw claude-opus-4.6 call (no schema, no rubric, no AST context) across 6 fixtures (3 triage, 3 PR review).
| Arm | Quality (mean, /5) | Cost/call | Latency p50 |
|---|---|---|---|
| aptu+mercury-2 | 4.8/5 | $0.0011 | 1,934 ms |
| raw claude-opus-4.6 | 2.2/5 | $0.0193 | 16,032 ms |
Measured across aptu #737, #850, #1094 (triage) and #1091, #1098, #1101 (PR review); n=1 per fixture.
aptu+mercury-2 is 17x cheaper and 8x faster than a raw claude-opus-4.6 call, while scoring more than twice as high on the structured rubric.
See docs/BENCHMARKS.md for full methodology, fixture breakdown, and C1-C5 scores.
Demo

Features
- AI Triage - Summaries, suggested labels, clarifying questions, and contributor guidance
- Issue Discovery - Find good-first-issues from curated repositories
- PR Analysis - AI-powered pull request review and feedback
- Prompt Customization - Override built-in system prompts per operation or append custom guidance via config
- Release Notes - AI-curated changelogs from merged PRs
- GitHub Action - Auto-triage incoming issues with labels and comments
- MCP Server - Model Context Protocol integration for AI assistants
- Multiple Providers - OpenRouter (default), Gemini, Groq, Cerebras, Z.AI, and ZenMux
- Local History - Track your contributions offline
- Multiple Outputs - Text, JSON, YAML, Markdown, and SARIF
Installation
# Homebrew (macOS/Linux)
# Cargo-binstall (fast)
# Cargo
MCP Server (hosted, read-only): https://aptu-mcp.fly.dev/mcp - no install required for AI assistant integrations.
Quick Start
Security Scanning
Aptu includes built-in security pattern detection for PR reviews. Scanning is performed locally, and no code is sent to external services.
See docs/SECURITY_SCANNING.md for SARIF upload and GitHub integration.
Prompt Customization
Aptu's built-in system prompts are compiled into the binary as defaults. You can override them per operation at runtime or append project-specific guidance globally.
See docs/CONFIGURATION.md for file paths, operation names, and examples.
GitHub Action
Auto-triage new issues with AI using any supported provider.
- uses: clouatre-labs/aptu@v0
with:
github-token: ${{ secrets.GITHUB_TOKEN }}
openrouter-api-key: ${{ secrets.OPENROUTER_API_KEY }}
Options: apply-labels, no-comment, skip-labeled, dry-run, model, provider.
See docs/GITHUB_ACTION.md for setup and examples.
MCP Server
Integrate aptu with AI tools via the Model Context Protocol (MCP). Supports stdio (goose, Claude Desktop) and HTTP (remote/containerized).
See docs/MCP_SERVER.md for client configuration and Docker deployment.
Configuration
See docs/CONFIGURATION.md for AI provider setup.
Models
Use aptu models list to discover available models from all configured providers.
Discovering models
aptu models list # all providers
aptu models list --provider openrouter # OpenRouter only
Filtering and sorting
| Flag | Description |
|---|---|
--provider |
Filter to a specific provider |
--sort name|context |
Sort by name or context window size |
--min-context N |
Show only models with at least N tokens of context |
--filter TEXT |
Filter by name or ID (case-insensitive substring match) |
Free-tier models
OpenRouter exposes pricing data for each model. Models with zero prompt and completion cost are labeled free in the output. Use --provider openrouter to browse free models.
Security
- OpenSSF Best Practices Silver - Fewer than 1% of open source projects reach this level
- SLSA Level 3 - Provenance attestations for all releases
- REUSE/SPDX - License compliance for all files
- Signed Commits - GPG-signed commits required
- Dependency Scanning - Automated updates via Renovate
See SECURITY.md for reporting and verification.
Architecture
Aptu is a multi-crate Rust workspace. See docs/ARCHITECTURE.md for the full crate structure, data flow, and key dependencies.
Roadmap
See docs/ROADMAP.md for the project direction across near-term, medium-term, and long-term horizons.
Contributing
We welcome contributions! See CONTRIBUTING.md for guidelines. See docs/REPO-STANDARDS.md for a full artifact map and rationale covering CI workflows, tooling, and security controls.
License
Apache-2.0. See LICENSE.