pi-action-runner

GitHub Action that runs AI-powered PR reviews using pi and optionally dora for code intelligence.

Comment @pi review on a PR to trigger a structured code review posted as a reply.

Setup

Option A: API key (recommended)

Use a static API key from your provider. Does not expire.

1. Add your API key as a repository secret named API_KEY (Settings > Secrets and variables > Actions).
2. Add the workflow:

# .github/workflows/pi-review.yml
name: Pi Review
on:
  issue_comment:
    types: [created]

jobs:
  review:
    if: github.event.issue.pull_request && startsWith(github.event.comment.body, '@pi ')
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
      issues: write
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: refs/pull/${{ github.event.issue.number }}/merge

      - uses: butttons/pi-action-runner@v0
        with:
          api_key: ${{ secrets.API_KEY }}

Option B: pi auth.json (fallback)

Use your local pi auth file. OAuth tokens rotate automatically, so the secret may need periodic updates.

base64 -i ~/.pi/agent/auth.json | pbcopy

Add as PI_AUTH secret, then:

      - uses: butttons/pi-action-runner@v0
        with:
          pi_auth: ${{ secrets.PI_AUTH }}

Usage

Comment on any PR:

@pi review

With additional context:

@pi review focus on error handling and edge cases

Only repository owners and members can trigger reviews.

Inputs

Input	Required	Default	Description
api_key	No	--	API key for the model provider. Preferred auth method.
pi_auth	No	--	Base64-encoded pi auth.json. Fallback if api_key is not set.
pi_model	No	openai/gpt-4.1	Model in provider/model-id format
use_dora	No	true	Enable dora code intelligence. Set to false to skip dora entirely.
dora_version	No	latest	Dora CLI release version
scip_install	No	bun install -g @sourcegraph/scip-typescript	SCIP indexer install command. Empty string to skip.
dora_pre_index	No	--	Commands to run after dora init but before indexing (e.g. install project deps)
dora_index_command	No	dora index	Override the index command
system_prompt	No	--	Path to a custom system prompt file (relative to repo root). See Customizing prompts.
review_template	No	--	Path to a custom review output template file (relative to repo root). See Customizing prompts.
extra_prompt	No	--	Additional instructions appended to every review

Either api_key or pi_auth must be provided. When both are set, api_key takes precedence.

The dora_version, scip_install, dora_pre_index, and dora_index_command inputs are ignored when use_dora is false.

Examples

With dora (default)

TypeScript/JavaScript (no extra config needed):

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.API_KEY }}

Rust:

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.API_KEY }}
    scip_install: 'cargo install rust-analyzer'

Python:

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.API_KEY }}
    scip_install: 'pip install scip-python'
    dora_pre_index: 'pip install -e .'

Skip the SCIP indexer (dora still provides file-level analysis):

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.API_KEY }}
    scip_install: ''

Without dora

Uses git diff, grep, find, and file reading for context gathering. No dora install, indexing, or SCIP tooling required.

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.API_KEY }}
    use_dora: 'false'

Different model

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.ANTHROPIC_KEY }}
    pi_model: 'anthropic/claude-sonnet-4'

Customizing prompts

The system prompt and review output template are fully replaceable. Default files are in prompts/:

• prompts/system-dora.md -- default system prompt when dora is enabled
• prompts/system-git.md -- default system prompt when dora is disabled
• prompts/review-template.md -- default review output structure

To customize, copy a default file into your repo and point the input to it:

- uses: butttons/pi-action-runner@v0
  with:
    api_key: ${{ secrets.API_KEY }}
    system_prompt: '.github/review-prompt.md'
    review_template: '.github/review-template.md'

System prompt

Use {base_branch} anywhere in your prompt -- it gets replaced with the PR's target branch (e.g. main).

When system_prompt is set, it replaces the entire default prompt. The use_dora toggle has no effect on the prompt content in this case -- you control everything.

The extra_prompt input and the per-review comment message are still appended after your custom prompt.

Review template

The review template defines the markdown structure the agent outputs. It gets appended to the system prompt under an "Output" heading with instructions to produce only that format.

How it works

1. Validates the commenter is a repo owner/member.
2. If dora is enabled: installs dora CLI and the SCIP indexer, runs dora init, optional pre-index setup, then dora index.
3. Runs pi with bash and read tools. With dora, the agent uses git diff, dora changes, dora file, dora rdeps, and other dora commands. Without dora, it uses git diff, grep, find, and direct file reading.
4. Posts a structured review comment on the PR.

Each step logs to GitHub Actions output for full visibility into the review process.

Review output

The default review template produces this structure:

• Summary -- what the PR does and why.
• Risk Assessment -- LOW, MEDIUM, or HIGH with justification.
• Issues -- bugs, security, correctness problems with severity and file locations.
• Suggestions -- improvements worth considering.
• Architecture -- structural concerns, only when applicable.

Override with review_template to use your own format.

Requirements

• GitHub Actions runner: ubuntu-latest
• One of: API_KEY secret (static API key) or PI_AUTH secret (base64 pi auth.json)
• With dora enabled (default): the action installs bun, dora (@butttons/dora), and the SCIP indexer.
• With dora disabled: the action only installs bun.

License

MIT