database connection.md
Connect Postgres for NestJS
Summary
Database connection for a NestJS app on Ample. Verified on NestJS: a managed PostgreSQL database auto-provisioned and injected as DATABASE_URL, with real queries succeeding at request time (records=ok). Build and start: npm install, nest build (TypeScript) then node dist/main.js on the node-22 template.
Infrastructure requirements
- Compute: verified (Apps run in isolated x86_64 Firecracker microVMs that auto-pause when idle and wake on request; sizes are the priced VM sizes.)
- Postgres: 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
- A NestJS project (npm install, nest build (TypeScript) then node dist/main.js on the node-22 template)
- A PostgreSQL driver reading DATABASE_URL at runtime
- An Ample account token with servers:write, databases:read
Exact tested configuration
- template:
node-22 - runtime:
node - size:
s-1vcpu-1gb - install:
npm install - build:
npm run build --if-present - start:
npm run start
Steps
- Build and start. npm install, nest build (TypeScript) then node dist/main.js on the node-22 template; the server must bind 0.0.0.0 on PORT.
- Read DATABASE_URL at runtime. Open connections from the environment inside handlers or a pool; omit DATABASE_URL to auto-provision a managed database or pass --env DATABASE_URL=... for an existing one.
- Verify. Fetch the live URL and /p/relational-records on the example; on failure read the build and runtime logs.
ample logs <deployment_id> --kind build
Tested examples
- NestJS pattern fixture (tests/deploy-canaries/nestjs-patterns): Verified database connection on NestJS.
Success checks
- app responds on its public URL (
/on the live URL, expect ample canary nestjs patterns) - relational-records check from the example (
/p/relational-recordson the live URL, expect see the pattern fixture checks)
Limitations
- Verified on the node-22 template at s-1vcpu-1gb; other sizes and NestJS major versions are not verified.
- Region, compliance attestations and request-duration limits are unknown and not claimed.
- Managed PostgreSQL 16 only; extensions, connection limits and backup or restore procedures are not verified.
Cost estimate
Estimated 10.00 USD per month (size prices from pricing.toml at build revision a1b8c38919e59cd035ebabaced73cf84ece24371).
- app server x1
s-1vcpu-1gb: 5.00 USD - managed PostgreSQL database x1
s-1vcpu-1gb: 5.00 USD
Always-on monthly price of the tested sizes; apps auto-pause when idle. Buckets are allocation-priced per quota and not included.
Verification evidence
- canary_run on 2026-09-21T02:34:39Z at revision
1d28ae0-dirty (CLI 0.1.21): NestJS pattern fixture deployed on Ample (npm install, nest build (TypeScript) then node dist/main.js on the node-22 template); for this guide: a managed PostgreSQL database auto-provisioned and injected as DATABASE_URL, with real queries succeeding at request time (records=ok). (expires 2027-03-20T02:34:39Z)
Last verified: 2026-09-21T02:34:39Z
Execution binding
MCP tool ample_deploy (registry mcp:ample_deploy), schema hash 876465fce906da0c observed 2026-09-21T03:19:59.461917+00:00 at revision 49962bcade4f, binding state current, required scopes: servers:write, databases:read.