Deployments Cicd

# Vercel Deployments & CI/CD

You are an expert in Vercel deployment workflows — `vercel deploy`, `vercel promote`, `vercel rollback`, `vercel inspect`, `vercel build`, and CI/CD pipeline integration with GitHub Actions, GitLab CI, and Bitbucket Pipelines.

## Deployment Commands

### Preview Deployment

```bash
# Deploy from project root (creates preview URL)
vercel

# Equivalent explicit form
vercel deploy
```

Preview deployments are created automatically for every push to a non-production branch when using Git integration. They provide a unique URL for testing.

### Production Deployment

```bash
# Deploy directly to production
vercel --prod
vercel deploy --prod

# Force a new deployment (skip cache)
vercel --prod --force
```

### Build Locally, Deploy Build Output

```bash
# Build locally (uses development env vars by default)
vercel build

# Build with production env vars
vercel build --prod

# Deploy only the build output (no remote build)
vercel deploy --prebuilt
vercel deploy --prebuilt --prod
```

**When to use `--prebuilt`:** Custom CI pipelines where you control the build step, need build caching at the CI level, or need to run tests between build and deploy.

### Promote & Rollback

```bash
# Promote a preview deployment to production
vercel promote <deployment-url-or-id>

# Rollback to the previous production deployment
vercel rollback

# Rollback to a specific deployment
vercel rollback <deployment-url-or-id>
```

**Promote vs deploy --prod:** `promote` is instant — it re-points the production alias without rebuilding. Use it when a preview deployment has been validated and is ready for production.

### Inspect Deployments

```bash
# View deployment details (build info, functions, metadata)
vercel inspect <deployment-url>

# List recent deployments
vercel ls

# View logs for a deployment
vercel logs <deployment-url>
vercel logs <deployment-url> --follow
```

## CI/CD Integration

### Required Environment Variables

Every CI pipeline needs these three variables:

```bash
VERCEL_TOKEN=<your-token>        # Personal or team token
VERCEL_ORG_ID=<org-id>           # From .vercel/project.json
VERCEL_PROJECT_ID=<project-id>   # From .vercel/project.json
```

Set these as secrets in your CI provider. Never commit them to source control.

### GitHub Actions

```yaml
name: Deploy to Vercel
on:
  push:
    branches: [main]

jobs:
  deploy:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Vercel CLI
        run: npm install -g vercel

      - name: Pull Vercel Environment
        run: ve