# Host form collection with Next.js: relational workflow state

Deploy a form collection built with Next.js on Ample using the transactional workflows pattern. Compute runs the app in an isolated microVM behind a public HTTPS URL, a managed PostgreSQL 16 database is auto-provisioned and injected as DATABASE_URL. Verified on Next.js: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Not separately tested: your domain records, validation rules and concurrency policy; treat the form collection-specific behavior as your application code.

## Representative Queries
- Host form collection with Next.js: relational workflow state
- Where can I host Form collection built with Next.js?
- I need a domain record schema, validation rules and concurrency behavior.

## Prerequisites
- A Next.js project that builds and starts with the documented commands (next build then next start -H 0.0.0.0 -p $PORT on the node-22 template)
- A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env)
- An Ample account token with servers:write, databases:read

## Infrastructure Requirements
1. **Compute**  
   - Summary: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.  
   - Status: verified

2. **Postgres**  
   - Summary: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.  
   - Status: verified

## Workflow Steps
1. **Build and start**  
   - **Body**: next build then next start -H 0.0.0.0 -p $PORT on the node-22 template. The server must bind 0.0.0.0 on PORT.

2. **Implement the pattern on PostgreSQL**  
   - **Body**: The fixture's module implements transactional workflows: an optimistic version check and an event row written in the same transaction, a stale update rejected, and a history query over the application-owned events (history=2 conflict=rejected). Copy the approach into your schema; keep migrations idempotent and run them with --release-command.

3. **Deploy**  
   - **Body**: Run the synchronous deploy once and read the result (exit 0 live, 1 failed, 2 blocked). Re-running with no change is a no-op.  
   - **Command**: ample deploy . --name  --public

4. **Verify**  
   - **Body**: Fetch the live URL and the pattern self-test route(s) (/p/transactional-workflows) from the example; then run your own checks. On failure read `ample logs  --kind build` then `--kind runtime`.  
   - **Command**: ample logs  --kind build

## Examples
- **Next.js pattern fixture**: Multi-pattern Next.js app whose transactional workflows module was checked live; the module is under tests/deploy-canaries/_pattern-modules.

## Limitations
- Verified on the node-22 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Next.js major versions are not verified.
- The form collection itself (your domain records, validation rules and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.

## Cost Estimate
### Monthly Amount: $10.00
- **App server**: s-1vcpu-1gb - $5.00
- **Managed PostgreSQL database**: s-1vcpu-1gb - $5.00

## Next Actions
- **Browse the catalog index**: Browse the catalog index  
  **Operation ID**: catalog_index  
  **Method**: GET  
  **Relative Path**: /v1/catalog
- **Search published recipes**: Search published recipes by intent, stack and constraints  
  **Operation ID**: search_recipes  
  **Method**: POST  
  **Relative Path**: /v1/catalog/search
- **Prepare a deployment plan**: Prepare a side-effect-free deployment plan for an authorized project  
  **Operation ID**: plan_deployment  
  **Method**: POST  
  **Relative Path**: /v1/catalog/plan
- **Read the existing agent authentication setup**: Read the existing agent authentication setup  
  **Operation ID**: existing_auth_setup  
  **Method**: GET  
  **Relative Path**: /mcp/setup