page:recipes:digital downloads:phoenix:relational catalog

Host Digital Downloads with Phoenix: Relational Catalog Data

Deploy a digital downloads 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 digital downloads-specific behavior as your application code.

Representative Queries

Host digital downloads with Phoenix: relational catalog data
Where can I host Digital downloads built with Phoenix?
I need catalog tables, transactional update logic and application-level access boundaries.

Resource Requirements

Compute
Postgres

Infrastructure Requirements

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

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.

Workflow Steps

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.
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.
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
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

Success Checks

App responds on its public URL:
Kind: http_get, Path: /, Expect: ample canary phoenix patterns
Transactional-workflows self-test:
Kind: http_get, Path: /p/transactional-workflows, Expect: tx=ok history=2 conflict=rejected

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 digital downloads 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
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.

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

Evidence Summary

Canary Run:
Summary: Phoenix pattern fixture deployed on Ample, 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. Observed At: 2026-09-20T23:45:31Z
Canary Run:
Summary: The same Phoenix app deployed with a --release-command migration; the marker it created was readable after activation.

Formats

Next Actions

Browse the catalog index
Action ID: browse-catalog
Method: GET
Relative Path: /v1/catalog
Search published recipes by intent, stack and constraints
Action ID: search-recipes
Method: POST
Relative Path: /v1/catalog/search Parameters:
- body:
  - limit: 5
  - query: Host digital downloads with Phoenix: relational catalog data
Prepare a side-effect-free deployment plan for an authorized project
Action ID: plan:page:recipes:digital-downloads:phoenix:relational-catalog
Method: POST
Relative Path: /v1/catalog/plan
Parameters:
- body:
  - inputs: {}
  - projectId: ""
  - recipeId: page:recipes:digital-downloads:phoenix:relational-catalog
  - recipeRevision: r1
Read the existing agent authentication setup
Action ID: auth-setup
Method: GET
Relative Path: /mcp/setup
Browse Digital Downloads
Action ID: browse:workload:digital-downloads
Method: GET
Relative Path: /v1/catalog/nodes/workload%3Adigital-downloads
Browse Phoenix
Action ID: browse:stack:framework-phoenix
Method: GET
Relative Path: /v1/catalog/nodes/stack%3Aframework-phoenix
Browse Transactional Workflows
Action ID: browse:pattern:transactional-workflows
Method: GET
Relative Path: /v1/catalog/nodes/pattern%3Atransactional-workflows
Browse Deploy Web App
Action ID: browse:intent:deploy-web-app
Method: GET
Relative Path: /v1/catalog/nodes/intent%3Adeploy-web-app