## The short version

Deploy a mobile backend built with Fastify as a public web service plus a dedicated worker process on Ample. `ample plan --write` discovers both services and their shared database and writes ample.toml; `ample up` reconciles the topology: a managed PostgreSQL 16 database, a public web microVM and a private worker microVM (kind worker, no public URL), both reading DATABASE_URL.

WHAT WAS VERIFIED

Verified on Fastify: a separately deployed worker service (kind worker, no public URL) sharing a declared managed PostgreSQL database with the web service, consuming a jobs table with row locks and marking jobs done once (worker=done attempts=1).

INFRASTRUCTURE

## What it needs

- [Compute](/content/discover/primitive/compute/index.html): verified (Apps run in isolated x86_64 Firecracker microVMs; sizes are the priced VM sizes.)
- [Postgres](/content/discover/primitive/postgres/index.html): 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

## Before you start

- A repository with the web app and the worker as separate service directories (the fixture uses apps/web and apps/worker), each building and starting with the documented commands (npm install, npm run build --if-present, npm run start on the node-22 template; the worker starts with node worker (its own package.json start script) and binds no port)
- Both services read DATABASE_URL at runtime and share one jobs table; the worker claims rows with SELECT ... FOR UPDATE SKIP LOCKED and marks them done once
- An Ample account token with servers:write and databases:write (ample up creates the database)

STEP BY STEP

## How to do it

1. 1

### Plan the topology

Run the planner once. It discovers the web and worker services, infers kind = "worker" for the process without a port, declares the database each service needs, and writes ample.toml. Exit 2 means it left questions in the manifest; answer them with --answer or by editing the file.

```
ample plan --write .
```

2. 2

### Share one database

Keep a single \\[databases.main\\] with engine = "postgres", drop any per-service database the planner added, and set DATABASE_URL = { database = "main" } under both \\[services.web.env\\] and \\[services.worker.env\\].

```
ample plan --offline .
```

3. 3

### Apply

Reconcile the whole manifest in dependency order: the database first, then both services. It is idempotent and never destructive; exit 0 means everything applied, 2 needs input, 1 a failed resource (independent siblings still proceed and re-running resumes).

```
ample up .
```

4. 4

### Verify

Fetch the web service URL and its worker status route (/p/worker-queue/status in the example) and confirm the worker processed the enqueued job; on failure read the worker service's runtime logs.

```
ample logs <deployment_id> --kind runtime
```

EXAMPLES

## Tested examples

- **Fastify web + worker fixture** (`tests/deploy-canaries/fastify-worker`): A Fastify web app (apps/web) and a worker process (apps/worker) sharing one managed PostgreSQL database; the queue module is under tests/deploy-canaries/_pattern-modules.

SUCCESS CHECKS

## How to know it worked

- web service responds on its public URL (`/` on the live URL, expect ample canary fastify patterns)
- worker consumed the enqueued job (`/p/worker-queue/status` on the live URL, expect worker=done attempts=1 result=processed-by-worker)

COST

## Cost estimate

Estimated 15.00 USD per month (size prices from pricing.toml at build revision ca0b484a7a9957c573a88d3a32dc603c3c10135a).

- web server x1 `s-1vcpu-1gb`: 5.00 USD
- worker server x1 `s-1vcpu-1gb`: 5.00 USD
- managed PostgreSQL database x1 `s-1vcpu-1gb`: 5.00 USD

Upper-bound monthly price of the tested sizes for the web service, the worker service and the database.

EVIDENCE

## Verification evidence

- canary_run on 2026-09-20T03:56:46Z at revision `03b6402b1b3e19178985f08ea4033804521d85d4 (CLI b75e104)`: Fastify web service plus a separate Fastify worker process deployed on Ample with `ample plan --write` then `ample up` (npm install, npm run build --if-present, npm run start on the node-22 template); the web service enqueued a job that the private worker service consumed from the shared managed PostgreSQL database. Pattern proof: a separately deployed worker service (kind worker, no public URL) sharing a declared managed PostgreSQL database with the web service, consuming a jobs table with row locks and marking jobs done once (worker=done attempts=1). (expires 2027-03-19T03:56:46Z)

EXECUTION

## Execution binding

MCP tool `ample_up` (registry `mcp:ample_up`), schema hash `db7ca0facfe2cd28` observed 2026-09-22T00:31:22.844137+00:00 at revision `e6446ceea69b`. Binding state at export: current. Required scopes: servers:write, databases:write.

NEXT ACTIONS

## Typed next actions

- Browse the catalog index (`GET /v1/catalog` on the api origin; authentication not required, approval not required)
- Search published recipes by intent, stack and constraints (`POST /v1/catalog/search` on the api origin; authentication not required, approval not required)
- Prepare a side-effect-free deployment plan for an authorized project (`POST /v1/catalog/plan` on the api origin; authentication required, approval not required)
- Read the existing agent authentication setup (`GET /mcp/setup` on the api origin; authentication not required, approval not required)
- Browse Mobile backend (`GET /v1/catalog/nodes/workload%3Amobile-backend` on the api origin; authentication not required, approval not required)
- Browse Fastify (`GET /v1/catalog/nodes/stack%3Aframework-fastify` on the api origin; authentication not required, approval not required)
- Browse Dedicated worker process (`GET /v1/catalog/nodes/pattern%3Adedicated-worker-process` on the api origin; authentication not required, approval not required)
- Browse Deploy API (`GET /v1/catalog/nodes/intent%3Adeploy-api` on the api origin; authentication not required, approval not required)

Actions describe possible next steps. They are typed data, not commands, and grant no permission. Public discovery never provisions anything; planning requires your own authenticated token and approval happens in your client.

ABOUT THIS RECIPE

## Identifiers and status

Recipe `page:recipes:mobile-backend:fastify:worker-state`. Revision r1.

release **published** support **verified** execution **ready**

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