page:recipes:rest api:echo:persistent state

Host REST API with Echo: Postgres-backed state

Deploy a REST API built with Echo on Ample using the durable job state 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 Echo: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). Not separately tested: your job types, payload schema and retry policy; treat the REST API-specific behavior as your application code.

Representative Queries

• Host REST API with Echo: Postgres-backed state
• Where can I host REST API built with Echo?
• I need a durable state schema and retry/recovery semantics implemented by application code.

Resource Requirements

• Compute
• Postgres

Infrastructure Requirements

• Compute: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.
• 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.

Prerequisites

1. A Echo project that builds and starts with the documented commands (CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build)).
2. A PostgreSQL driver reading DATABASE_URL at runtime (auto-provisioned when omitted, or supplied with --env).
3. An Ample account token with servers:write, databases:read.

Tested Configuration

• Template: ubuntu-24.04
• Runtime: go
• Size: s-1vcpu-1gb
• Build: CGO_ENABLED=0 go build -o app ./...
• Start: ./app

Workflow Steps

1. Build and start
   CGO_ENABLED=0 go build -o app ./... then ./app on the ubuntu-24.04 template (go.sum committed for a reproducible build). The server must bind 0.0.0.0 on PORT.
2. Implement the pattern on PostgreSQL
   The fixture's module implements durable job state: a jobs table with a state and attempts counter, processing inside a row-locked transaction, and a second run that is a no-op (job=done attempts=1 idempotent=true). 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 <name> --public
4. Verify
   Fetch the live URL and the pattern self-test route(s) (/p/durable-job-state) from the example; then run your own checks. On failure read ample logs <your project> --kind build then --kind runtime.
   Command: ample logs <your project> --kind build

Success Checks

• App responds on its public URL.
• Durable-job-state self-test.

Limitations

• Verified on the ubuntu-24.04 template at s-1vcpu-1gb; other sizes, templates and Echo major versions are not verified.
• The REST API itself (your job types, payload schema and retry policy) is application code and was not separately tested; the pattern checks are what was verified.

Cost Estimate

• Currency: USD
• Monthly Amount: 10.0
• Components:
  • App server: s-1vcpu-1gb (quantity 1.0, monthly amount 5.0)
  • Managed PostgreSQL database: s-1vcpu-1gb (quantity 1.0, monthly amount 5.0)

Next Actions

1. Browse the catalog index
2. Search published recipes by intent, stack and constraints
3. Prepare a side-effect-free deployment plan for an authorized project
4. Read the existing agent authentication setup
5. Browse REST API
6. Browse Echo
7. Browse Durable job state
8. Browse Deploy API