## Migrate Vercel app: Rails

Move Rails compute from Vercel app to Ample, one component at a time. Destination verified on Ample: the app built, started and answered on its public HTTPS URL with encrypted configuration delivered. Source procedure: Copy environment variables from the Vercel project settings (or `vercel env pull`) into an env file you keep out of the repository. Not migrated automatically: Edge middleware, ISR revalidation, image optimization, cron jobs and Vercel integrations are not migrated and are unverified on Ample. Cutover: Add the custom domain with `ample domain add`, set the documented DNS records, keep the Vercel deployment until traffic is verified, then remove the domain from Vercel. Rollback: keep the source untouched until you confirm; nothing at the source is changed or deleted by this guide.

### Prerequisites
- Authorized access to the Vercel app source and its export tooling
- An inventory of every component in scope and out of scope
- A validated backup or copy before any cutover
- An Ample account token with servers:write, databases:read

### Resource Requirements
- primitive:compute
- primitive:postgres

### Infrastructure Requirements
1. **Compute**: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
2. **Postgres**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

### Migration Steps
1. **Inventory the source**: List what Vercel app provides beyond the component you are moving. Out of scope here: Edge middleware, ISR revalidation, image optimization, cron jobs and Vercel integrations are not migrated and are unverified on Ample.
2. **Source step 1**: Copy environment variables from the Vercel project settings (or `vercel env pull`) into an env file you keep out of the repository.
3. **Source step 2**: Note the framework preset, build command and output directory; Ample detects the same from the repository.
4. **Source step 3**: List Vercel-only features in use: edge middleware, ISR revalidation, image optimization, cron jobs, integrations.
5. **Deploy on Ample in parallel**: `bundle install into vendor/bundle from Gemfile.lock`, then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production. Pass the exported variables with --env; keep the source running.
6. **Validate before cutover**: Run the app's own checks and, for data, compare counts and checksums.
7. **Cut over**: Add the custom domain with `ample domain add`, set the documented DNS records, keep the Vercel deployment until traffic is verified, then remove the domain from Vercel.
8. **Rollback**: Point DNS or configuration back to the source.

### Success Checks
- Destination app responds on its public URL
- Configuration-secrets check from the destination example
- Relational-records check from the destination example
- Data or object counts and checksums match the source

### Limitations
- Documentation only: nothing is executed automatically and no execution binding is offered.
- The source-side procedure is documented from Vercel app's standard tooling and was not executed in this catalog's evidence.
- Verified on the ruby-3.4 template at s-1vcpu-1gb; region, compliance and request-duration limits are unknown.

### Cost Estimate
- **Currency**: USD
- **Monthly Amount**: $10.00
- **Components**:
  - App server: s-1vcpu-1gb (1.0, $5.00)
  - Managed PostgreSQL database: s-1vcpu-1gb (1.0, $5.00)
- **Note**: Destination always-on monthly price of the tested sizes; apps auto-pause when idle. Source costs are unknown to Ample.

### Evidence Summary
- Destination side verified: the Rails pattern fixture deployed on Ample and its checks passed. The source-side export from Vercel app is documented from the vendor's standard tooling and was not executed by this catalog's evidence.

### Last Verified At
2026-09-20T21:55:28Z

### Next Actions
- **Browse the catalog index**
- **Search published recipes by intent**
- **Prepare a deployment plan for an authorized project**
- **Read the existing agent authentication setup**
- **Browse Vercel app**
- **Browse Rails**
- **Browse Migrate compute**