Pull Request Comment Trigger

A GitHub Action that monitors pull request descriptions and comments for specific trigger phrases, enabling conditional workflow execution based on comment content.

Description

This action scans pull request descriptions and comments for designated trigger words or phrases. When a trigger is detected, it sets output variables that can be used by subsequent workflow steps to conditionally execute tasks. This is particularly useful for:

• Triggering deployments via PR comments (e.g., @deploy staging)
• Running specific test suites when requested (e.g., #run-integration-tests)
• Enabling manual approval workflows through comment triggers
• Creating interactive PR workflows that respond to team member commands

The action supports both exact matching and prefix-only matching modes, and can optionally add emoji reactions to comments when triggers are detected.

Inputs

Parameter	Required	Default	Description
trigger	Yes	-	The trigger phrase to search for in PR descriptions and comments (e.g., "@deploy", "#build-android")
prefix_only	No	false	When set to true, the trigger must appear at the beginning of the comment. When false, it can appear anywhere in the text
reaction	No	-	Optional emoji reaction to add when trigger is found (e.g., "rocket", "eyes", "thumbs_up")

Outputs

Parameter	Description
triggered	String value "true" if the trigger phrase was found, "false" otherwise
comment_body	The full text content of the comment or PR description that was analyzed

Example Workflow

name: Conditional Deployment
on:
  pull_request:
    types: [opened, synchronize]
  issue_comment:
    types: [created]

jobs:
  check-trigger:
    runs-on: ubuntu-latest
    steps:
      - name: Check for deployment trigger
        id: trigger-check
        uses: step-security/pull-request-comment-trigger@v1
        with:
          trigger: '@deploy staging'
          reaction: 'rocket'
          prefix_only: 'false'
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      - run: 'echo Triggered'
        if: steps.trigger-check.outputs.triggered == 'true'

Usage Notes

• Event Configuration: Your workflow must listen to both pull_request and issue_comment events to capture triggers from both PR descriptions and comments
• Permissions: When using the reaction parameter, the GITHUB_TOKEN environment variable is required
• Reaction Types: Reaction must be one of the reactions here: https://developer.github.com/v3/reactions/#reaction-types
• Trigger Matching: The action performs case-sensitive matching. Use prefix_only: true for commands that should only be recognized at the start of comments