## Host marketplace with Rails: relational catalog data

Deploy a marketplace built with Rails 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 Rails: 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 marketplace-specific behavior as your application code.

### Representative Queries
- Host marketplace with Rails: relational catalog data
- Where can I host Marketplace built with Rails?
- I need catalog tables, transactional update logic and application-level access boundaries.

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

### Framework
Rails

### Workload
Marketplace

### Release Status
published

### Support Status
verified

### Execution Status
ready

### Prerequisites
- A Rails project that builds and starts with the documented commands (bundle install into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production)
- 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

### Workflow Steps
1. **Build and start**  
   `bundle install` into vendor/bundle from Gemfile.lock (development and test groups skipped), then Puma via `rails server` reading PORT on the ruby-3.4 template with RAILS_ENV=production. The server must bind 0.0.0.0 on PORT.
2. **Implement the pattern on PostgreSQL**  
   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**  
   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.  
   `ample deploy . --name  --public`
4. **Verify**  
   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`.  
   `ample logs  --kind build`

### Limitations
- Verified on the ruby-3.4 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Rails major versions are not verified.
- The marketplace itself (your domain records, validation rules and concurrency policy) is application code and was not separately tested; the pattern checks are what was verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Apps auto-pause when idle and wake on the next request; always-on is an operator setting, not a plan feature.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified; apps and their databases are placed together.

### Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **Authoritative**: true
- **Basis**: size prices from pricing.toml (loaded by the API) at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty
- **Components**:
  - app server
    - Size: s-1vcpu-1gb
    - Quantity: 1.0
    - Monthly Amount: 5.0
  - managed PostgreSQL database
    - Size: s-1vcpu-1gb
    - Quantity: 1.0
    - Monthly Amount: 5.0
- **Note**: Always-on monthly price of the tested sizes; apps and databases auto-pause when idle. Buckets are allocation-priced per quota and not included.

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

### Next Actions
- **Browse the catalog index**: GET /v1/catalog
- **Search published recipes by intent, stack and constraints**: POST /v1/catalog/search  
  Body: {"limit":5,"query":"Host marketplace with Rails: relational catalog data"}
- **Prepare a side-effect-free deployment plan for an authorized project**: POST /v1/catalog/plan  
  Body: {"inputs":{},"projectId":"","recipeId":"page:recipes:marketplace:rails:relational-catalog","recipeRevision":"r1"}