PR Welcome Comment Action 👋

Automatically post a welcome and guidance comment on pull requests. This action helps maintainers encourage first-time contributors and guides reviewers on how to inspect, run, and review changes.

Features

• Automated Welcomes: Greets pull request authors with next steps and review instructions.
• Customizable Message:
  • custom-message: Provide your own markdown message. Supports {{prNumber}} and {{baseBranch}} placeholders.

---

Usage

Create a workflow file in your repository at .github/workflows/pr-welcome.yml:

Default Configuration

name: PR Welcome

on:
  pull_request_target:
    types: [opened]

# Required permissions for reading and writing PR comments
permissions:
  issues: write
  pull-requests: write

jobs:
  pr-welcome:
    runs-on: ubuntu-latest
    steps:
      - name: PR Welcome
        uses: Atliac/pr-welcome@v1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}

With Custom Message

      - name: PR Welcome
        uses: Atliac/pr-welcome@v1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          custom-message: |
            ## Hello and Welcome!

            Thanks for opening PR #{{prNumber}} pointing to branch `{{baseBranch}}`.

            Please review our contributing guidelines!

---

Inputs

Input	Description	Required	Default
github-token	The GitHub token to use for API requests.	Yes	—
custom-message	An optional custom Markdown message to post. You can use {{prNumber}} and {{baseBranch}} as placeholders.	No	'' (uses default guidance template)

---

Permissions

The action requires issues: write and pull-requests: write permissions to post comments on pull requests:

permissions:
  issues: write
  pull-requests: write

---

Why pull_request_target?

This action uses the pull_request_target event instead of pull_request. Here's why:

Event	Runs in context of	Token permissions	Works for fork PRs?
pull_request	The PR's (fork's) repository	Read-only (for public repos)	❌ Will get 403 when posting comments
pull_request_target	The base repository	Full permissions as defined in the workflow	✅ Works as expected

Important

Because pull_request_target runs workflows from the base branch (e.g. main), any changes to .github/workflows/pr-welcome.yml in a PR will not take effect for that PR. The workflow always executes the version that already exists on the default branch. If you modify the workflow file in a PR and expect the new behavior to apply immediately, it won't — the changes only activate after the PR is merged.

---

Releases & Versioning

This action follows Semantic Versioning.

When referencing the action in your workflows, you can pin to a major version tag (like @v1) to automatically receive backward-compatible updates:

• Major Tag (e.g. @v1): Automatically updated to point to the latest minor/patch release of that version.
• Specific Version Tag (e.g. @v1.0.0): Recommended if you require absolute immutability and want to pin to a exact release.