AI Pull Request Describer

Automatically generate descriptions for pull requests using any OpenAI-compatible AI model (ChatGPT, DeepSeek, Groq, Ollama, etc.).

When you open or update a pull request labeled with "ai-describe", this action will automatically generate a concise list of changes and update the pull request description (body) or post a comment.

Demo / Review

Features

• High-Performance: Uses pre-built binaries for near-instant startup (no Docker build overhead).
• Multi-Model Support: Works with OpenAI, DeepSeek, Groq, or any OpenAI-compatible API.

Requirements

• API key from your chosen AI provider (OpenAI, DeepSeek, etc.).

Usage

Option 1: Manual Label Mode (Default)

Add the label ai-describe to any pull request to trigger generation.

Option 2: Auto-Update Mode (Recommended)

Enable auto-update-enabled: true to automatically generate and update the PR description every time new commits are pushed, no labels required. The description will always stay up to date with the latest changes.

Add the following workflow file to your repository in .github/workflows/ai-pr-describer.yml:

name: AI Pull Request Describer

on:
  pull_request_target:
    types: [opened, synchronize, labeled, reopened]

jobs:
  describe:
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: AI Pull Request Describer
        uses: fajarhide/ai-pr-describer@v1.1.2 # Use the latest released version for best performance
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          github-api-base-url: 'https://api.github.com'
          openai-api-key: ${{ secrets.OPENAI_API_KEY }}
          openai-model: '${{ secrets.OPENAI_MODEL }}'
          openai-base-url: '${{ secrets.OPENAI_BASE_URL }}'
          max-tokens: 2000
          max-context-tokens: 256000
          auto-update-enabled: false

AI Provider Examples

OpenAI (Default)

openai-model: 'gpt-4o'

DeepSeek

openai-api-key: ${{ secrets.OPENAI_API_KEY }}
openai-model: 'deepseek-chat'
openai-base-url: 'https://api.deepseek.com'

Groq

openai-api-key: ${{ secrets.OPENAI_API_KEY }}
openai-model: 'llama3-8b-8192'
openai-base-url: 'https://api.groq.com/openai/v1'

GLM (Zhipu AI)

openai-api-key: ${{ secrets.OPENAI_API_KEY }}
openai-model: 'glm-4'
openai-base-url: 'https://open.bigmodel.cn/api/paas/v4'
max-context-tokens: 128000 # adjust based on model capability

Ollama (Local/Self-hosted)

openai-api-key: 'ollama' # usually not required but cannot be empty
openai-model: 'llama3'
openai-base-url: 'http://your-ollama-host:11434/v1'

How It Works

flowchart LR
    A[PR Event Occurs] --> B{auto-update-enabled ?}
    B -->|No| C{Has ai-describe label?}
    B -->|Yes| D[✅ Run Automatically]
    
    C -->|No| E[Skip / Do Nothing]
    C -->|Yes| D
    
    D --> F[Fetch full PR diff]
    F --> G[AI generates complete description]
    G --> H[Update PR body]
    
    style D fill:#0ea5e9,color:white
    style H fill:#10b981,color:white

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Supported events:

• opened - when PR is first created
• synchronize - every time new commits are pushed
• labeled - when ai-describe label is added
• reopened - when PR is reopened

Configuration

Name	Required	Description	Default
github-token	✅ Yes	GitHub API token, use ${{ secrets.GITHUB_TOKEN }}
openai-api-key	✅ Yes	API Key for your AI provider (OpenAI, DeepSeek, Groq, etc.)
openai-model	❌ No	AI model to use	gpt-3.5-turbo
openai-base-url	❌ No	Custom base URL for OpenAI-compatible APIs
max-tokens	❌ No	Maximum output tokens for generated description	2000
max-context-tokens	❌ No	Maximum total context tokens (input diff + prompt + output)	32000
auto-update-enabled	❌ No	Auto update PR description on every new commit. No labels required.	false

Performance

This action is now a Composite Action using pre-built binaries. It typically runs in under 15 seconds, compared to ~2.5 minutes for Docker-based actions.

Important

To use this action in your own fork, you must first create a Release (e.g. v1.0.0) to trigger the build and upload of binaries.

Troubleshooting 💡

"Missing required environment variables"

This error occurs when the required secrets are not passed to the action. Ensure you have:

1. Created a secret named OPENAI_API_KEY in your repository settings (Settings > Secrets and variables > Actions).
2. Passed the secrets in your workflow file as shown in the Usage section.

Note

You do not need to create GITHUB_TOKEN yourself. It is a built-in secret provided automatically by GitHub Actions. You only need to create custom secrets like OPENAI_API_KEY etc.

Pull Requests from Forks

By default, GitHub does not pass secrets to workflows triggered by pull requests from forked repositories for security reasons. If a contributor from a fork opens a PR, the action will fail with a "Missing required environment variables" error because it cannot access your OPENAI_API_KEY.

To fix this, you can:

• Manually run the action on the PR after it's been opened by a maintainer.
• (Use with caution) Use the pull_request_target event instead of pull_request, but be aware of the security implications.

Changelog

Please see CHANGELOG for more information what has changed recently.

Contributing

Please see CONTRIBUTING for details.

Credits

• Fajar Hidayat
• All Contributors

License

The MIT License (MIT). Please see License File for more information.