# Connect Postgres for Express

Connect an Express app to PostgreSQL on Ample. Read DATABASE_URL at runtime: when you supply one with --env it is delivered encrypted and takes precedence; when you supply none and the app needs PostgreSQL, Ample auto-provisions a managed PostgreSQL 16 database and injects its connection string.

## Representative Queries
- Connect Postgres for Express
- Where can I host Connect Postgres built with Express?
- I need driver setup, connection settings, secret handling and a real connection test.

## Prerequisites
- The pg driver reading process.env.DATABASE_URL
- Either a production DATABASE_URL to pass with --env, or nothing (auto-provision)
- An Ample account token with servers:write and databases:read

## Workflow Steps
1. **Read the URL at runtime**  
   Construct the pg Pool from process.env.DATABASE_URL inside the app; never commit credentials.
2. **Choose the source of the database**  
   Pass --env DATABASE_URL=... for an existing database, or omit it to let Ample provision a managed one on first deploy and reuse it on redeploys.
   ```bash
   ample deploy . --name  --public --env DATABASE_URL=postgres://...
   ```
3. **Test the connection through the app**  
   Expose a route that runs a trivial query and returns postgres=ok, then deploy and fetch it.
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.
   ```bash
   ample logs  --kind build
   ```

## Examples
- **Express + pg canary**: Auto-provisioned managed database with a real insert and count.
- **Supplied DATABASE_URL**: An explicit connection string delivered as an encrypted environment variable.

## Success Checks
- Database route reports a live connection  
   **Path**: /items  
   **Expect**: postgres=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.
- A supplied URL is used as-is; Ample does not validate reachability of external databases before the release starts.

## Cost Estimate
- **Currency**: USD  
- **Monthly Amount**: 10.0  
- **Basis**: Size prices from pricing.toml at build revision 1ac5595375130d45290090e82ed0f554ccd45405-dirty  
### Components
1. **App server**  
   - **Size**: s-1vcpu-1gb  
   - **Quantity**: 1.0  
   - **Monthly Amount**: 5.0  
2. **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.