prpack-action

Pack each pull request into one markdown file optimized for LLM code review.

Want to see what it produces without setting up a workflow? Paste a public PR into the browser demo and you'll see the exact output this action uploads as an artifact on every PR.

A GitHub Action wrapper around prpack. On every PR, it builds a single markdown file containing the diff and the full post-change content of every touched file, uploads it as an artifact, and leaves a summary comment. Drop the artifact into Claude / Cursor / your model of choice and ask for a review that can actually see what didn't change.

The technique behind it is written up at length here: Your LLM code reviewer is reading half the file.

Reproducible side-by-side proof that this matters: prpack/examples/invoice-refactor. Paste the raw diff into Claude; paste the packed context into Claude; compare.

prpack v0.2.0 also ships a native --review [angle] flag that calls Anthropic and streams the review for you. Currently this action runs in pack-only mode; if you want CI to auto-review, you can extend the workflow to set ANTHROPIC_API_KEY and call npx -y github:Lucas2944/prpack --review security --yes directly in a subsequent step. See prpack v0.2.0 release.

Five-minute setup tutorial: Add an LLM PR reviewer to your GitHub Actions in 5 minutes (no API key).

Usage

The minimum:

# .github/workflows/prpack.yml
name: prpack

on:
  pull_request:

permissions:
  contents: read
  pull-requests: write

jobs:
  pack:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - uses: Lucas2944/prpack-action@v1

That's it. On every PR, you'll get:

• An artifact called prpack-context containing the packed markdown
• A summary comment on the PR with file count and token estimate

Open the artifact, paste it into Claude or Cursor, and ask "Review this PR."

Inputs

Input	Default	Description
base	PR base, or origin/main	Base ref for the diff.
head	${{ github.sha }}	Head ref.
config	—	Path in your repo to a .prpack.yml config file.
include-tests	false	Pull in adjacent test files even if they didn't change.
exclude	—	Newline-separated globs to exclude.
max-bytes	200000	Skip individual files larger than this.
no-content	false	Diff-only output, no full file content (smaller pack).
output-path	prpack-context.md	Where to write the packed file.
upload-artifact	true	Upload the packed file as a workflow artifact.
post-summary-comment	true	Post a summary comment on the PR.

Outputs

Output	Description
output-path	Path to the packed markdown.
size-bytes	Size of the packed markdown in bytes.
files-changed	Number of files included in the pack.

Recipes

Skip the comment, just upload the artifact.

- uses: Lucas2944/prpack-action@v1
  with:
    post-summary-comment: 'false'

Diff-only for huge PRs.

- uses: Lucas2944/prpack-action@v1
  with:
    no-content: 'true'

Use your own preset.

Drop a .prpack/security.yml (or wherever you like) into your repo:

preface: |
  This PR touches our auth flow. Focus the review on input validation,
  authorization checks, and token handling.
reviewPrompt: |
  You are a security reviewer. For every issue you find, give file:line,
  severity (CRITICAL / HIGH / MEDIUM / LOW), why it matters, and a
  concrete fix.

Then point the action at it:

- uses: Lucas2944/prpack-action@v1
  with:
    config: .prpack/security.yml
    include-tests: 'true'

Exclude generated paths.

- uses: Lucas2944/prpack-action@v1
  with:
    exclude: |
      pnpm-lock.yaml
      dist/**
      **/*.snap

Why

Pasting a raw diff into a model gets you generic feedback. The model can't see the rest of the file, so it pattern-matches on the diff and says "looks good" to changes that broke things outside the diff. Adding the full post-change content of every touched file is a one-line fix that turns useless reviews into reviews that catch real bugs. This action does it for you on every PR.

Permissions

The action needs contents: read to run git diff. It needs pull-requests: write only if post-summary-comment is true (the default). For PRs from forks, GitHub-issued tokens are read-only by default — set the workflow to pull_request_target and trust accordingly, or disable comments.

How it works

It's a composite action. Internally it runs:

npx -y github:Lucas2944/prpack --base <base> --head <head> --out prpack-context.md ...

Then uploads the file with actions/upload-artifact@v4 and posts the summary comment with gh pr comment. No new dependencies in your repo, no Docker container.

Curated review presets

For four ready-made review-style presets (security / performance / tests / architecture) plus a one-page workflow guide on getting useful reviews out of LLMs, see the prpack Pro Pack — free or pay-what-you-want. The action stays MIT.

License

MIT.