Apply Database Schema Changes for SvelteKit

Summary

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

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.

   ample deploy . --name <app-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.

   ample logs <app-name> --kind build
   

Success Checks

• Migration marker is readable:
  • Kind: http_get
  • Path: /migrated
  • Expect: migrated=release-ok

Examples

• SvelteKit release-command canary Description: node migrate.cjs runs before activation against the auto-provisioned managed database. Source Ref: tests/deploy-canaries/sveltekit-postgres-app

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)
• 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.

Evidence Summary

• Kind: canary_run
• Summary: The same SvelteKit 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.

Next Actions

• Browse the catalog index
• Search published recipes by intent, stack, and constraints.
• Prepare a side-effect-free deployment plan for an authorized project.