Signal Lens

Context-first maintainer PR review for open-source repos

Catches what diff-only review misses: CI weakening, security boundaries, duplicate utilities, and missing tests — with evidence, not opinions.

Surfaces: Agent Skill · CLI · GitHub Action · MCP (optional) — v2.0.1

Repository: https://github.com/simhanson123/signal-lens

Signal Lens (signal-lens) is context-first maintainer PR review — not an MCP-only tool. Slug: CLI, npm, Action, GitHub repo.

Why maintainers use it

AI and agent-generated PRs look clean but hide risks in workflows, tests, and security boundaries. signal-lens compresses those signals so you can decide faster:

| Risk | What signal-lens checks | |------|------------------------| | CI weakening | continue-on-error, removed tests, coverage drops | | Security boundaries | Untrusted input in workflows, hardcoded secrets | | Duplicate utilities | New helpers vs existing symbols (Tree-sitter index) | | Test gaps | Source changes without test updates |

Features

| Area | Commands / Surfaces | |------|---------------------| | Agent Skill | /signal-lens — Claude Code + Grok/Codex (auto MCP or CLI) | | PR Review | signal-lens review, GitHub Action | | Inline Comments | signal-lens post-inline, review --post-inline | | Tree-sitter Index | signal-lens index → SQLite symbol + import graph | | Issue Triage | signal-lens triage | | Release Notes | signal-lens release | | Auto-fix Draft | signal-lens fix, /signal-lens fix | | Slash Commands | /signal-lens explain, false-positive, fix, release-notes | | MCP Server (optional) | signal-lens mcp — 5 resources, 7 tools, 4 prompts | | GitHub App (experimental) | signal-lens serve + github-app/manifest.yml | | AI Providers | OpenAI, Anthropic, Ollama (local), mock | | Output | Markdown, JSON, SARIF (Code Scanning) |

No API key required

Static analyzers run without any API key. For AI review without cloud APIs, use Ollama.

Quick Start

# From source (npm package not yet published)
git clone https://github.com/simhanson123/signal-lens.git
cd signal-lens && npm install && npm run build

# Index repository symbols
node dist/cli.js index

# Review branch (static — no API key)
node dist/cli.js review --base main --head HEAD --static-only

Agent Skill (recommended entry point)

/signal-lens
/signal-lens --branch my-feature

Copy into your OSS repo:

cp -r skills/signal-lens .claude/skills/signal-lens   # Claude Code
cp -r skills/signal-lens .grok/skills/signal-lens     # Grok / Codex

Auto-routes: MCP tools when connected, else CLI. See docs/skills.md.

signal-lens capabilities

GitHub Action

- uses: simhanson123/signal-lens/[email protected]
  with:
    output-format: all
    post-comment: "true"
    post-inline-comments: "true"
    fail-on-blocker: "true"

CLI

signal-lens review --base main --head HEAD --static-only
signal-lens review --base main --head HEAD --output all -f report
signal-lens index
signal-lens capabilities

Ollama (Local AI Review)

ollama pull qwen2.5-coder:7b
SIGNAL_LENS_PROVIDER=ollama signal-lens review --base main --head HEAD

MCP (optional integration)

For Cursor, Claude Desktop, or other MCP hosts:

{
  "mcpServers": {
    "signal-lens": {
      "command": "signal-lens",
      "args": ["mcp"],
      "cwd": "/path/to/your/repo"
    }
  }
}

Configuration

Copy .signal-lens.yml to your repo root.

Development

git clone https://github.com/simhanson123/signal-lens.git
cd signal-lens
npm install
npm test
npm run build

Documentation

• Agent Skills
• Architecture
• Security
• OpenAI Codex for OSS Plan
• Changelog

License

MIT