pr-reviewer

pr-reviewer

A flue agent that reviews a unified diff. A lead agent loads the diff, delegates one task each to a correctness-reviewer and a style-reviewer, runs the tests the diff touches with run_tests, then synthesizes the two passes into a single Markdown review (a one-line verdict followed by findings ordered by severity) and posts it once. fixtures/demo-pr is the small store codebase the demo pull requests change; its integration tests wait on purpose so a run_tests call can outlive a five-minute prompt cache. Model: Claude Sonnet 5 through OpenRouter; pi-ai reads OPENROUTER_API_KEY.

Run it locally

OPENROUTER_API_KEY=... npm install
OPENROUTER_API_KEY=... npm run demo

npm run demo reviews fixtures/sample.diff and npm run demo:fix reviews fixtures/fix.diff. Without POST_TO_GITHUB=true set, the review is written to review.md instead of posted to a pull request.

Run it on pull requests

GitHub only runs workflows from the repository root. The workflow for this app is .github/workflows/review.yml at the root of this repository. It runs only for pull requests that change apps/pr-reviewer/, and it runs every step inside apps/pr-reviewer.

1. Add the OpenRouter API key as a repository secret:

   gh secret set OPENROUTER_API_KEY
   

2. Open a pull request that changes a file in apps/pr-reviewer/. The workflow runs on opened and synchronize, diffs the PR against its base branch, and posts the review as a PR comment.

In a fork, enable Actions on the fork first. A pull request from a fork to this repository does not get the secrets, so open the pull request inside your fork.

To use the agent in another repository, copy this app to that repository's root, copy the workflow, and remove the paths filter and the working-directory default.

Sentry

Set SENTRY_DSN (locally in .env, in CI as the SENTRY_DSN repository secret) to send traces to Sentry. One run produces a trace with a root span for the lead agent, a chat span per lead model turn, a tool span per read_diff, read_file, run_tests, and post_review call, and two subagent spans (one for correctness-reviewer, one for style-reviewer) with their own chat and tool spans nested underneath. environment is github-actions in CI and local otherwise; release is the workflow's GITHUB_SHA.

pi-ai caches the prompt prefix with Anthropic's default five-minute lifetime. Set PI_CACHE_RETENTION=long to ask for the one-hour lifetime.