Commit Summarizer

A lightweight webhook service that listens for GitHub push events, generates plain-English summaries using a local LLM (via Ollama), and posts them to Slack.

Designed for teams where non-technical stakeholders want to stay informed about code changes without reading diffs.

How it works

1. GitHub sends a push webhook to this service
2. The service verifies the HMAC-SHA256 signature
3. Commit data (messages, authors, files changed) is sent to a local Ollama model
4. An AI-generated summary is posted to a Slack channel

Requirements

• Python 3.10+
• Ollama running locally with a model pulled (default: qwen2.5:3b)
• A Slack app with an incoming webhook (for posting summaries) and slash commands (for /pause and /resume)
• A GitHub webhook secret

Setup

1. Install Ollama and pull a model

curl -fsSL https://ollama.com/install.sh | sh
ollama pull qwen2.5:3b

2. Install dependencies

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

3. Configure environment

cp .env.example .env
# Edit .env with your actual values

4. Run

python app.py

Or deploy as a systemd service:

[Unit]
Description=Commit Summarizer Webhook
After=network.target ollama.service

[Service]
Type=simple
User=your-user
WorkingDirectory=/path/to/commit-summarizer
ExecStart=/path/to/commit-summarizer/venv/bin/python app.py
EnvironmentFile=/path/to/commit-summarizer/.env
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

5. Configure GitHub webhook

In your repo: Settings → Webhooks → Add webhook

Field	Value
Payload URL	https://your-domain.com/webhook
Content type	application/json
Secret	(your GITHUB_WEBHOOK_SECRET)
Events	Just the push event

6. Configure Slack slash commands (optional)

To pause and resume summaries from Slack, add two slash commands to your Slack app:

1. https://api.slack.com/apps → your app → Slash Commands → Create New Command
   • Command: /pause
   • Request URL: https://your-domain.com/slack/command
   • Save
2. Repeat for /resume (same Request URL)
3. Basic Information → copy the Signing Secret into SLACK_SIGNING_SECRET
4. Get the channel ID where the commands are allowed (right-click the channel → View channel details → bottom of the panel) and put it in SLACK_ALLOWED_CHANNEL_ID
5. Reinstall the app to your workspace if Slack prompts you

When paused, the service still ACKs GitHub webhooks but skips the Ollama summary and the Slack post.

Endpoints

• POST /webhook — GitHub webhook receiver
• POST /slack/command — Slack slash command handler (/pause, /resume)
• GET /health — Health check (returns paused status)

License

AGPL 3.0