# Apply database schema changes for Fastify

## Summary
Apply database schema changes for a Fastify app on Ample with a release command. `node migrate.js` runs against the injected DATABASE_URL before the new release goes live, and the release fails instead of activating if the migration fails.

## Representative Queries
- Apply database schema changes for Fastify
- Where can I host Apply database schema changes built with Fastify?
- I need a framework-specific schema migration and rollback procedure; no managed migration service is assumed.

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

## Infrastructure Requirements
1. **Compute**  
   Verified: Yes  
   Summary: Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.  
   Path: /discover/primitive/compute

2. **Postgres**  
   Verified: Yes  
   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.  
   Path: /discover/primitive/postgres

## Prerequisites
- A migration command that reads DATABASE_URL and exits non-zero on failure
- A PostgreSQL database (supplied or managed)
- An Ample account token with servers:write and databases:read

## Workflow Steps
1. **Write an idempotent migration**  
   Create tables and markers with IF NOT EXISTS or a migration framework so a re-run is safe.

2. **Deploy with the release command**  
   Ample runs the command before activation; a non-zero exit fails the release.  
   Command: `ample deploy . --name <app_name> --public --release-command "node migrate.js"`

3. **Verify the marker through the app**  
   Serve a route (/migrated) that reads something only the migration creates.

4. **Verify**  
   Fetch the live URL and run the success checks below. On failure read the build log, then the runtime log, fix the cause and deploy again; do not blind-retry.  
   Command: `ample logs <app_name> --kind build`

## Examples
### Fastify release-command canary
- **Description**: `node migrate.js` runs before activation against the auto-provisioned managed database.
- **Source Reference**: tests/deploy-canaries/fastify-postgres-api

## Success Checks
- **Migration marker is readable**  
   Kind: http_get  
   Path: /migrated  
   Expect: migrated=release-ok

## Limitations
- Verified on the node-22 template at s-1vcpu-1gb; other templates and sizes are not verified by this recipe.
- 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 managed databases are placed together; cross-node shared databases are unsupported.
- The release command runs once per release on the app VM; there is no separate migration runner or rollback of a partially applied migration.

## Cost Estimate
- **Currency**: USD
- **Monthly Amount**: 10.0
- **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**: Apps and managed databases auto-pause when idle; the estimate is the always-on monthly price of the tested sizes. Plan quotas and budgets apply.

## Last Verified At
- 2026-09-20T00:22:15Z

## Formats
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