# Apply database schema changes for Astro

## Summary
Apply database schema changes for a Astro app on Ample with a release command. `node migrate.cjs` 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 Astro
- Where can I host Apply database schema changes built with Astro?
- 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**: 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**: Managed PostgreSQL 16 runs in its own microVM and is auto-provisioned when an app needs a database and no DATABASE_URL is supplied.

## Workload
Apply database schema changes

## 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

## Tested Configuration
- **Template**: node-22
- **Runtime**: node
- **Size**: s-1vcpu-1gb
- **Install**: npm install
- **Build**: npm run build --if-present
- **Start**: npm run start

## 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.
   ```shell
   ample deploy . --name  --public --release-command "node migrate.cjs"
   ```
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.
   ```shell
   ample logs  --kind build
   ```

## Examples
- **Astro release-command canary**: `node migrate.cjs` runs before activation against the auto-provisioned managed database.

## Success Checks
- **Migration marker is readable**: HTTP GET on `/migrated` expects `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**: s-1vcpu-1gb - $5.00/month
  - **Managed PostgreSQL database**: s-1vcpu-1gb - $5.00/month
- **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.

## Evidence Summary
- **Kind**: canary_run  
  **Summary**: The same Astro app deployed with --release-command node migrate.cjs; /migrated reported the migration marker.  
  **Observed At**: 2026-09-20T01:42:25Z
  **Implementation Revision**: 199ff1dfd52683832ae75d3f98b53a7a4bff7f96-dirty (CLI e3181f5)
  **Expires At**: 2027-03-19T01:42:25Z
  **Scope**: { "cliVersion": "0.1.20", "platform": "hosted-beta", "template": "node-22" }

## Last Verified At
2026-09-20T01:42:25Z

## Unknowns
- Region availability is unknown until a verified region fact is recorded.
- Compliance attestations are unknown; none are claimed.

## Formats
- **HTML**: [View Here](/content/guides/astro/schema-changes/index.html)
- **Markdown**: [View Here](/content/guides/astro/schema-changes.md)
- **JSON**: [View Here](https://api.ample.computer/v1/catalog/recipes/page%3Aguides%3Aastro%3Aschema-changes)

## Next Actions
1. **Browse the catalog index**: `GET /v1/catalog`
2. **Search published recipes by intent, stack and constraints**: `POST /v1/catalog/search` with query `Apply database schema changes for Astro`
3. **Prepare a side-effect-free deployment plan for an authorized project**: `POST /v1/catalog/plan`
4. **Read the existing agent authentication setup**: `GET /mcp/setup`
5. **Browse Astro**: `GET /v1/catalog/nodes/stack%3Aframework-astro`
6. **Browse Configure deployment**: `GET /v1/catalog/nodes/intent%3Aconfigure-deployment`
7. **Browse Transactional workflows**: `GET /v1/catalog/nodes/pattern%3Atransactional-workflows`