## Host marketplace with Phoenix: relational catalog data

### Summary
Deploy a marketplace built with Phoenix 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 Phoenix: 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 Phoenix: relational catalog data
- Where can I host Marketplace built with Phoenix?
- I need catalog tables, transactional update logic and application-level access boundaries.

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

### Infrastructure Requirements
1. **Compute**  
   - Status: verified  
   - Summary: 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**  
   - Status: verified  
   - 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.

### Framework
Phoenix

### Workload
Marketplace

### Release Status
Published

### Support Status
Verified

### Execution Status
Ready

### Prerequisites
- A Phoenix project that builds and starts with the documented commands (`mix deps.get`, `MIX_ENV=prod mix compile` and `mix release` in the builder, then the release bin script with `PHX_SERVER=true` on the elixir-1.18 template; `PORT`, `DATABASE_URL` and `SECRET_KEY_BASE` read in `config/runtime.exs`)
- 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`

### Tested Configuration
- **Template**: elixir-1.18  
- **Runtime**: elixir  
- **Size**: s-1vcpu-1gb  
- **Install**: `mix local.hex --force && mix local.rebar --force && MIX_ENV=prod mix deps.get --only prod`  
- **Build**: `MIX_ENV=prod mix compile && MIX_ENV=prod mix release --overwrite`  
- **Start**: `PHX_SERVER=true _build/prod/rel/$(ls _build/prod/rel | head -n 1)/bin/$(ls _build/prod/rel | head -n 1) start`

### Workflow Steps
1. **Build and start**  
   - `mix deps.get`, `MIX_ENV=prod mix compile` and `mix release` in the builder, then the release bin script with `PHX_SERVER=true` on the elixir-1.18 template; `PORT`, `DATABASE_URL` and `SECRET_KEY_BASE` read in `config/runtime.exs`. 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.  
   - Command: `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`.  
   - Command: `ample logs  --kind build`

### Limitations
- Verified on the elixir-1.18 template at s-1vcpu-1gb with the example fixture; other sizes, templates and Phoenix 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.

### Evidence Summary
- **Canary Run**  
   - Summary: Phoenix pattern fixture deployed on Ample (mix deps.get, `MIX_ENV=prod mix compile` and `mix release` in the builder, then the release bin script with `PHX_SERVER=true` on the elixir-1.18 template; `PORT`, `DATABASE_URL` and `SECRET_KEY_BASE` read in `config/runtime.exs`); checks passed for transactional-workflows and configuration-secrets. Pattern proof: 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).  
   - Observed At: 2026-09-20T23:45:31Z  
   - Implementation Revision: 4d1511e574302f3904b75088bd4048a0975218b3-dirty (CLI 0.1.21)  
   - Expires At: 2027-03-19T23:45:31Z  
   - Scope: {"checks":["/p/transactional-workflows"],"pattern":"pattern:transactional-workflows","template":"elixir-1.18"}

### Formats
- **HTML**: [https://ample.computer/recipes/marketplace/phoenix/relational-catalog](/content/recipes/marketplace/phoenix/relational-catalog/index.html)  
- **Markdown**: [https://ample.computer/recipes/marketplace/phoenix/relational-catalog.md](/content/recipes/marketplace/phoenix/relational-catalog.md)  
- **JSON**: [https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Amarketplace%3Aphoenix%3Arelational-catalog](https://api.ample.computer/v1/catalog/recipes/page%3Arecipes%3Amarketplace%3Aphoenix%3Arelational-catalog)

### Next Actions
- **Browse the catalog index**: GET /v1/catalog  
- **Search published recipes by intent, stack and constraints**: POST /v1/catalog/search  
- **Prepare a side-effect-free deployment plan for an authorized project**: POST /v1/catalog/plan  
- **Read the existing agent authentication setup**: GET /mcp/setup  
- **Browse Marketplace**: GET /v1/catalog/nodes/workload%3Amarketplace  
- **Browse Phoenix**: GET /v1/catalog/nodes/stack%3Aframework-phoenix  
- **Browse Transactional workflows**: GET /v1/catalog/nodes/pattern%3Atransactional-workflows  
- **Browse Deploy web app**: GET /v1/catalog/nodes/intent%3Adeploy-web-app