Creating an Adapter

1. Create the adapter

For another SQL engine, the sql folder probably does most of the work: MySQL, MariaDB and SQLite share it, and each only supplies an SqlDriver with its own dialect. Otherwise, add a folder under packages/database/src/adapters/ and export a factory that returns DatabaseAdapter:

export function createExampleAdapter(options: { url: string }): DatabaseAdapter {
  return {
    ...createExampleRepositories(options),
    provider: "postgresql",
    async connect() {},
    async disconnect() {},
    async ping() {
      return { ok: true, latencyMs: 0, serverVersion: null };
    },
    async initialize() {
      return { applied: [] };
    },
  };
}

connect must throw DatabaseConnectionError with a message free of credentials.

2. Implement every repository

Parse input with the shared schemas. Translate unique-constraint failures into ConflictError, and missing records into NotFoundError.

users.createFirstOwner must be atomic: when five requests race, exactly one succeeds.

3. Add migrations

Implement Migration and use runMigrations from packages/database/src/migrations. Each migration must be safe to run twice.

4. Run the contract suite

import { describeDatabaseContract } from "../../repositories/contract-suite";
 
describeDatabaseContract("example", {
  setup,
  reset,
  teardown,
  unreachable,
  unreachableSecret: "s3cret",
});

5. Register it

Add a case in createDatabase in packages/database/src/index.ts, and set the engine's status to supported in DATABASE_ENGINES. The dashboard reads that list, so it updates automatically. Update this documentation and the install page in the same change.