pr-ready.yml

# Rewrite PR body with Claude (pr-ready skill) on ready-for-review label.
name: PR Ready Body

on:
  pull_request:
    types: [labeled]

permissions:
  contents: read
  pull-requests: write

concurrency:
  group: pr-ready-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  rewrite-body:
    if: >-
      github.event.label.name == 'ready-for-review' &&
      github.actor != 'dependabot[bot]' &&
      github.event.pull_request.head.repo.full_name == github.repository
    runs-on: ubuntu-latest
    timeout-minutes: 10
    steps:
      - name: Checkout (skill + PR template only)
        uses: actions/checkout@v7
        with:
          sparse-checkout: |
            .claude/skills/pr-ready/SKILL.md
            .github/PULL_REQUEST_TEMPLATE.md
          sparse-checkout-cone-mode: false
          persist-credentials: false

      - name: Rewrite PR body with Claude
        uses: actions/github-script@v9
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
        with:
          script: |
            const fs = require('fs');
            const pr = context.payload.pull_request;

            if (!process.env.ANTHROPIC_API_KEY) {
              core.setFailed('ANTHROPIC_API_KEY secret is not set');
              return;
            }

            const skill = fs.readFileSync('.claude/skills/pr-ready/SKILL.md', 'utf8');
            const template = fs.readFileSync('.github/PULL_REQUEST_TEMPLATE.md', 'utf8');

            const { data: rawDiff } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pr.number,
              mediaType: { format: 'diff' },
            });
            // Cap huge diffs (lockfiles, fixtures) to fit context.
            const DIFF_CHAR_CAP = 400000;
            const diff = rawDiff.length > DIFF_CHAR_CAP
              ? rawDiff.slice(0, DIFF_CHAR_CAP) + '\n\n[diff truncated]'
              : rawDiff;

            const prompt = `You are rewriting the body of a GitHub pull request.

            Follow the skill below exactly. Keep the repository PR template's sections (## Issue, ## Checklist, ## Notes) and fill them from the current body; replace the template's ## Summary with the skill's three sections (## Summary, ## Evidence, ## Merge Danger) in that order, between ## Issue and ## Checklist. Keep any "Closes ..." issue reference verbatim; if none, write "Closes #PLEASE_TYPE_ISSUE_NUMBER". Preserve checklist [x]/[ ] states from the current body. Do not invent evidence: only cite tests, numbers or screenshots present in the current body or diff. Output ONLY the markdown body.

            <skill>
            ${skill}
            </skill>

            <pull_request_template>
            ${template}
            </pull_request_template>

            PR title: ${pr.title}
            Branch: ${pr.head.ref} -> ${pr.base.ref}

            <current_body>
            ${pr.body || '(empty)'}
            </current_body>

            <diff>
            ${diff}
            </diff>`;

            const response = await fetch('https://api.anthropic.com/v1/messages', {
              method: 'POST',
              headers: {
                'Content-Type': 'application/json',
                'x-api-key': process.env.ANTHROPIC_API_KEY,
                'anthropic-version': '2023-06-01',
                'anthropic-beta': 'server-side-fallback-2026-07-01',
              },
              body: JSON.stringify({
                model: 'claude-opus-5-5',
                max_tokens: 8000,
                fallbacks: 'default',
                output_config: { effort: 'medium' },
                messages: [{ role: 'user', content: prompt }],
              }),
            });

            const data = await response.json();
            if (!response.ok) {
              core.setFailed(`Anthropic API error: ${JSON.stringify(data)}`);
              return;
            }
            if (data.stop_reason === 'refusal') {
              core.setFailed(`Claude declined the request: ${JSON.stringify(data.stop_details)}`);
              return;
            }

            const body = data.content
              .filter((block) => block.type === 'text')
              .map((block) => block.text)
              .join('')
              .trim();
            if (!body) {
              core.setFailed('Empty response from Claude');
              return;
            }

            const original = pr.body || '(empty)';
            await github.rest.pulls.update({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pr.number,
              body: `${body}\n\n<details><summary>Previous PR description</summary>\n\n${original}\n\n</details>`,
            });