MySQL

A Railway.MySQL is MySQL as a Service: the official mysql:9 image, a Volume at /var/lib/mysql, MYSQL_* / MYSQL_URL variables, and an optional TCP proxy for the public URL. The IaC helper is Railway.mysql.

Private hostname is {name}.railway.internal. From a Service, yield ConnectMySQL. From a laptop, use publicConnectionUri.

Create MySQL

Pass a Project. Alchemy generates a unique name, password, volume, and a public TCP proxy.

const site = yield* Railway.Project("Site");
const db = yield* Railway.MySQL("Db", { project: site });

Changing project replaces MySQL

A new service + volume are created in the new Project. The old service and volume are deleted. Data is not copied.

Connect from a Service

Yield ConnectMySQL in Service init. Provide ConnectMySQLHttp. Pass conn.connectionString to Drizzle or SQL.

import * as Drizzle from "alchemy/Drizzle/MySQL";
import * as HttpServerResponse from "effect/unstable/http/HttpServerResponse";

export default class Api extends Railway.Service<Api>()(
  "Api",
  {
    project: Site,
    main: import.meta.url,
    build: { install: ["mysql2"] },
  },
  Effect.gen(function* () {
    const conn = yield* Railway.ConnectMySQL(Db);
    const db = yield* Drizzle.MySQL(conn.connectionString);
    return {
      fetch: Effect.gen(function* () {
        const rows = yield* db.execute("select 1 as ok", "objects");
        return HttpServerResponse.json({ rows });
      }),
    };
  }).pipe(Effect.provide(Railway.ConnectMySQLHttp)),
) {}

connectionString is the private URI ({name}.railway.internal:3306). Packed into the Service env — not Config.redacted.

To store Railway’s ${{Db.MYSQL_URL}} template instead of a resolved URI, pass Railway.ref (Railway.ref(Db, "MYSQL_URL")) as a Variable value.

Public TCP

public (default true) creates a TCP proxy on 3306. publicConnectionUri is {domain}:{proxyPort} for laptop access.

const db = yield* Railway.MySQL("Db", {
  project: site,
  public: false,
});

Where next

Postgres is the same shape for Postgres. Mongo is MongoDB. TcpProxy is the public TCP resource. The MySQL reference lists every prop. The ConnectMySQL reference is the runtime binding.