Ability to run against a PR in another repo

[moltar]

I'd like to manage a single repo with Claude Code action config that we can re-use across the org and multiple repos.

I want to be able to trigger a workflow manually, pass it a repo name and a PR ID and then Claude Code would run against that.

[masseater]

Here's how I do it: I've set up a workflow_dispatch workflow to run claude-code-action, taking the target repository and PR number as inputs. After checking out the repository containing the action definition, it also checks out the target repository and PR. Using the SessionStart hook, I instruct Claude to navigate to the target repository's directory.

This works for now, but ideally, I'd like to be able to specify the working directory directly when launching the action.

I'm attaching a sample YAML below. It's a simplified version of what I use in a private repository, so it may not work as-is, but I hope it serves as a helpful reference.

name: "Claude Code Action"

on:
  workflow_dispatch:
    inputs:
      target_repo:
        description: "target repository"
        required: true
        type: string
      pr_number:
        description: "pull request number"
        required: true
        type: string

permissions:
  contents: read
  pull-requests: write
  actions: read
  checks: read

jobs:
  claude-code-action:
    name: "claude-code-action"
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - name: Get PR branch
        id: pr
        env:
          # Note: To access another repository, you need a PAT with appropriate permissions
          # instead of the default GITHUB_TOKEN
          GH_TOKEN: ${{ secrets.GH_PAT }}
          TARGET_REPO: ${{ inputs.target_repo }}
          PR_NUMBER: ${{ inputs.pr_number }}
        run: |
          branch=$(gh pr view "$PR_NUMBER" --repo "$TARGET_REPO" --json headRefName -q '.headRefName')
          echo "branch=$branch" >> $GITHUB_OUTPUT
      - name: Checkout target repository
        uses: actions/checkout@v6
        with:
          repository: ${{ inputs.target_repo }}
          ref: ${{ steps.pr.outputs.branch }}
          path: target-repo
          # Note: For private repositories, use SSH key or PAT for authentication
          ssh-key: ${{ secrets.PRIVATE_SSH_KEY }}
      - name: Run Claude Code Action
        uses: anthropics/claude-code-action@v1
        with:
          anthropic_api_key: ${{ secrets.ANTHROPIC_API_KEY }}
          github_token: ${{ secrets.GH_PAT }}
          show_full_output: true
          additional_permissions: |
            actions: read
          prompt: "Check the PR and start working."

[moltar]

@masseater but does it leave the review on the right PR? Because looking the action code the PR ID is hardcoded and is passed from the environment of the running action. Running it via workflow would produce no PR ID value and there's no way to override it.