Add Comment (by flxbl-io)

A GitHub Action to add or update comments on Pull Requests and Issues with support for comment deduplication using unique message IDs.

Features

• Add comments to PRs and Issues
• Update existing comments using a unique message ID
• Automatic comment truncation for large messages
• Works in pull_request, issue, and other workflow contexts
• Simple, focused API

Usage

Basic Usage

- uses: flxbl-io/add-comment@v1
  with:
    message: |
      ## Build Results

      Build completed successfully!
    token: ${{ secrets.GITHUB_TOKEN }}

Update Existing Comment

Using message-id ensures that subsequent runs update the same comment instead of creating duplicates:

- uses: flxbl-io/add-comment@v1
  with:
    message: |
      ## Deployment Status

      Deployed to production at ${{ github.event.head_commit.timestamp }}
    message-id: deployment-status
    token: ${{ secrets.GITHUB_TOKEN }}

Comment on Specific Issue/PR

- uses: flxbl-io/add-comment@v1
  with:
    message: 'This is related to the current work.'
    issue-number: 123
    token: ${{ secrets.GITHUB_TOKEN }}

Cross-Repository Comment

- uses: flxbl-io/add-comment@v1
  with:
    message: 'Cross-repo notification'
    issue-number: 456
    repository: owner/other-repo
    token: ${{ secrets.PAT_TOKEN }}

Inputs

Input	Description	Required	Default
message	The message content to post as a comment (supports Markdown)	Yes	-
issue-number	The issue or pull request number to comment on	No	Auto-detected from context
pr-number	Alias for issue-number (for pull request context)	No	Auto-detected from context
repository	The repository in owner/repo format	No	${{ github.repository }}
token	GitHub token for API authentication	No	${{ github.token }}
message-id	Unique identifier for the comment. Used to find and update existing comments instead of creating duplicates	No	-

Outputs

Output	Description
comment-id	The ID of the created or updated comment
comment-created	Whether a new comment was created (true/false)
comment-updated	Whether an existing comment was updated (true/false)

Examples

Conditional Status Comment

- uses: flxbl-io/add-comment@v1
  if: always()
  with:
    message: |
      ## CI Status: ${{ job.status }}

      ${{ job.status == 'success' && 'All checks passed!' || 'Some checks failed.' }}
    message-id: ci-status
    token: ${{ secrets.GITHUB_TOKEN }}

Multi-Line Report

- uses: flxbl-io/add-comment@v1
  with:
    message: |
      ## Test Results

      | Metric | Value |
      |--------|-------|
      | Tests Run | 150 |
      | Passed | 148 |
      | Failed | 2 |

      <details>
      <summary>Failed Tests</summary>

      - `test_login_flow`
      - `test_checkout_process`

      </details>
    message-id: test-results
    token: ${{ secrets.GITHUB_TOKEN }}

How Message ID Works

When you provide a message-id, the action:

1. Searches existing comments on the issue/PR for a hidden marker
2. If found, updates that comment with the new message
3. If not found, creates a new comment with the marker

This prevents duplicate comments when workflows run multiple times.

Comment Size Limits

GitHub has a 64KB limit on comment size. If your message exceeds this limit, it will be automatically truncated with a notice appended.

Development

Build

npm install
npm run build

Test

npm test

Lint

npm run lint

License

See LICENSE for details.