Databases on Deno Deploy

Overview

Deno Deploy provides built-in database support with automatic environment isolation. You don't need to manage connection strings or worry about mixing production and development data.

Available Database Engines

Engine	Description
Deno KV	Fast, globally distributed key-value store hosted by Deno
PostgreSQL	Connect your own PostgreSQL or provision managed Postgres via Prisma

Key Concept: Timelines

Deno Deploy automatically creates isolated databases for each environment:

• Production: {app-id}-production
• Git branches: {app-id}--{branch-name}
• Preview deployments: {app-id}-preview

This means your preview deployments won't accidentally modify production data.

Database CLI Commands

Use deno deploy database to manage databases from the command line.

List Databases

# List all databases in your organization
deno deploy database list

# Search for databases by name
deno deploy database list my-prefix

Provision a Database

Create a new managed database:

# Provision a new Deno KV database
deno deploy database provision my-database --kind denokv

# Provision a new Prisma PostgreSQL database (requires --region)
deno deploy database provision my-database --kind prisma --region us-east-1

Link an External Database

Link an existing external postgres database by providing a connection string:

deno deploy database link my-database "postgres://user:pass@host:5432/db"

Assign / Detach

Connect or disconnect a database from an app:

# Assign a database to an app
deno deploy database assign my-database --app my-app

# Detach a database from an app
deno deploy database detach my-database --app my-app

Deno Deploy creates separate databases for each timeline automatically.

Query a Database

Run queries directly from the CLI:

deno deploy database query my-database production "SELECT * FROM users LIMIT 10"

The second argument is the timeline name (e.g., production, preview, or a branch name), which can be found in the output of deno deploy database list.

Delete a Database

deno deploy database delete my-database

Connecting in Code

Deno KV

No configuration needed - just call Deno.openKv():

const kv = await Deno.openKv();

// Deno Deploy automatically connects to the right database
// based on your current environment (production, preview, etc.)

PostgreSQL

Deno Deploy injects standard environment variables that most PostgreSQL libraries detect automatically:

• DATABASE_URL - Full connection string
• PGHOST, PGPORT, PGDATABASE, PGUSER, PGPASSWORD - Individual components

// Recommended: npm:pg (best PostgreSQL driver for Deno Deploy)
import pg from "npm:pg";
const pool = new pg.Pool(); // Reads DATABASE_URL from environment automatically
const { rows } = await pool.query("SELECT * FROM users");

Local Development

With Tunnel

Use --tunnel to connect your local dev server to your hosted development database:

deno task --tunnel dev

This gives you access to the same database environment variables locally.

Without Tunnel

• Deno KV: Data stays in memory during local development
• PostgreSQL: Point to a local PostgreSQL instance or use the tunnel

Migrations

Deno Deploy supports pre-deploy commands that run before each deployment. Use these for database migrations:

{
  "deploy": {
    "preDeploy": ["deno task db:migrate"]
  }
}

Sharing Databases

Multiple apps can share the same database instance. Each app gets its own isolated databases per timeline, even when sharing.

Documentation

• Databases overview: https://docs.deno.com/deploy/reference/databases/
• Deno KV reference: https://docs.deno.com/deploy/reference/deno_kv/