Getting started

Prerequisites

• A Cloudflare Workers project with a wrangler.jsonc (or wrangler.toml).
• CLOUDFLARE_API_TOKEN and CLOUDFLARE_ACCOUNT_ID as repository or environment secrets.

Cloudflare token scopes

The API token needs:

Permission	Level
Workers Scripts	Edit
D1	Edit
Workers KV Storage	Edit
Workers R2 Storage	Edit
Account → Workers Subdomain	Read

Add the workflow

Create .github/workflows/preview.yml:

name: Preview
on:
  pull_request:
    types: [opened, synchronize, reopened, closed]

concurrency:
  group: preview-pr-${{ github.event.pull_request.number }}
  cancel-in-progress: false

permissions:
  contents: read
  pull-requests: write

jobs:
  preview:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: oven-sh/setup-bun@v2
        with: { bun-version: 1.3.14 }
      - run: bun install
      - uses: BitByBit-B3/cf-pr-preview-action@v1
        with:
          worker-prefix: myapp-preview
          db-prefix: myapp-preview
        env:
          CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
          CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}

That's it. Open a PR and the action:

1. Creates myapp-preview-pr-<N> Worker + D1 + KV + R2.
2. Applies your D1 migrations.
3. Deploys to a workers.dev URL and posts a sticky PR comment.
4. Deletes everything when the PR closes.

Install your deps first

wrangler deploy runs your project's build.command, so set up your runtime (bun/npm/pnpm) and install before the action. Point wrangler-command at your package manager if it isn't bun.

Next

• Sync your dev D1 + R2 into previews
• Full input reference