Upload source maps with GitHub Actions

Uploading source maps with GitHub Actions requires your build to have already generated source maps. This action does not build your project, it only injects source map metadata into the built files and uploads them to PostHog. Make sure to run your production build first (for example, npm run build).

Add a workflow step to run the PostHog upload action after your build:

name: Upload source maps to PostHog

on:
  push:
    branches: [main]

jobs:
  build_and_upload:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm
      - run: npm ci
      - run: npm run build

      # Inject and upload source maps using the PostHog action
      - name: Inject & upload source maps to PostHog
        uses: PostHog/upload-source-maps@v0.4.6
        with:
          directory: dist
          env-id: ${{ secrets.POSTHOG_ENV_ID }}
          cli-token: ${{ secrets.POSTHOG_CLI_TOKEN }}
          # host: https://eu.posthog.com # Required only for EU cloud
          # project: my-awesome-project  # Optional; falls back to repo name
          # version: ${{ github.sha }}   # Optional; falls back to current commit SHA

This step:

• Injects a //# chunkId=... comment into your built source files so PostHog can match them with uploaded source maps
• Uploads the source maps to your PostHog project

We recommend storing env-id and cli-token in GitHub Secrets (for example, POSTHOG_ENV_ID and POSTHOG_CLI_TOKEN).

1. Confirm symbol sets are present in PostHog after the workflow runs.

2. Confirm your served production files include an injected comment at the end of the file similar to:

//# chunkId=0197e6db-9a73-7b91-9e80-4e1b7158db5c

You must deploy the injected build artifacts to production. PostHog reads the injected chunkId metadata during error capture to resolve stack traces. If you deploy files that were not processed by the action, uploaded source maps cannot be used to unminify your stack traces.