slackapi/slack-github-action: Send Slack Notifications

By Kaveh Alemi·Latchkey

slack-github-action posts messages to Slack from your workflow, via webhook or Web API.

Notify a channel when a build fails or a deploy ships. It supports incoming webhooks and the Slack Web API with a bot token.

Key inputs (with:)

• webhook / webhook-type: incoming webhook URL and mode.
• method: a Slack Web API method like chat.postMessage.
• token: a Slack bot token for Web API calls.
• payload: the JSON message payload.

Example workflow

jobs:
  notify:
    runs-on: ubuntu-latest
    if: failure()
    steps:
      - uses: slackapi/slack-github-action@v2
        with:
          webhook: ${{ secrets.SLACK_WEBHOOK_URL }}
          webhook-type: incoming-webhook
          payload: |
            {"text": "Build failed on ${{ github.ref_name }}"}

On any runner

This action runs on any runner. Latchkey managed runners run it unchanged.

Pinning and supply-chain hygiene

A third-party action runs arbitrary code with access to your workflow token. Version tags are mutable, so @v4 can change under you without any commit in your repository.

# mutable: the tag can be repointed at any time
- uses: some/action@v4

# immutable: pin to the commit SHA, with the version in a comment
- uses: some/action@e2b3f4a5c6d7e8f9a0b1c2d3e4f5a6b7c8d9e0f1  # v4.1.2

Key takeaways

• Webhook mode is simplest; Web API mode is more capable.
• Gate it with if: failure() to alert only on failures.
• Store the webhook URL or bot token as a secret.

Frequently asked questions

Related guides

References

• GitHub Actions documentation