Variable

Source: src/Railway/Variable.ts

A Railway.Variable is a project- or service-scoped env var. Railway injects it into services in that environment. The plaintext is never stored in attributes.

Create a Variable

Wrap the value with Redacted.make so it is never logged. Omit name and Alchemy generates an ownership-stamped name. Shared (no service) variables apply to every service in the environment.

const site = yield* Railway.Project("Site");
const dbUrl = yield* Railway.Variable("DatabaseUrl", {
  project: site,
  value: Redacted.make("postgres://…"),
});

Changing project replaces the Variable

The value is created on the new Project. The old name is deleted.

Env-var name

name is the env-var services see. It is stored as-is (case-sensitive).

export const ApiToken = Railway.Variable("ApiToken", {
  project: Site,
  name: "API_TOKEN",
  value: Redacted.make("sk_live_…"),
});

Changing name replaces the Variable

Railway cannot rename a variable. Alchemy creates the new name, then deletes the old one.

Environment

Defaults to the Project’s primary environment. Pass a Railway.Environment (or { environmentId }) to target another one.

const staging = yield* Railway.Environment("Staging", { project: site });
const token = yield* Railway.Variable("StagingToken", {
  project: site,
  environment: staging,
  value: Redacted.make("sk_staging_…"),
});

Changing environment replaces the Variable

The value is created in the new environment. The old name is deleted.

Service-scoped

Pass service to attach the variable to one service instead of the shared project set.

const api = yield* Railway.Service("Api", {
  project: site,
  image: "hashicorp/http-echo",
});
const token = yield* Railway.Variable("ApiToken", {
  project: site,
  service: api,
  name: "API_TOKEN",
  value: Redacted.make("sk_live_…"),
});

Variable references

value may be a Railway.ref(resource, key) template instead of a plaintext secret. Upsert stores ${{LogicalName.KEY}} (or ${{shared.NAME}}) — not a resolved URI. Railway interpolates it. Next to ConnectPostgres: use ConnectPostgres for a typed client inside an Effect-native Service; use Railway.ref when you want Railway’s own ${{Db.DATABASE_URL}} interpolation (IaC db.env.DATABASE_URL).

Reference Postgres DATABASE_URL

const db = yield* Railway.Postgres("Db", { project: site });
const api = yield* Railway.Service("Api", {
  project: site,
  image: "hashicorp/http-echo",
});
const databaseUrl = yield* Railway.Variable("DatabaseUrl", {
  project: site,
  service: api,
  name: "DATABASE_URL",
  value: Railway.ref(db, "DATABASE_URL"),
});

Shared variable

yield* Railway.Variable("SentryDsn", {
  project: site,
  name: "SENTRY_DSN",
  value: Redacted.make("https://…"),
});
yield* Railway.Variable("ApiSentry", {
  project: site,
  service: api,
  name: "SENTRY_DSN",
  value: Railway.ref("shared", "SENTRY_DSN"),
});

Rotate the value

Updating value is in place via variableUpsert. Deploys are skipped (skipDeploys: true); the Service resource owns deploys.

export const ApiToken = Railway.Variable("ApiToken", {
  project: Site,
  name: "API_TOKEN",
  value: Redacted.make("sk_live_rotated"),
});

Module-scope declarations

Declare the Project once. Pass it into every child. Resource-valued props accept the resource or an Effect producing it.

src/secrets.ts

import * as Railway from "alchemy/Railway";
import * as Redacted from "effect/Redacted";

export const Site = Railway.Project("Site");
export const ApiToken = Railway.Variable("ApiToken", {
  project: Site,
  name: "API_TOKEN",
  value: Redacted.make("sk_live_…"),
});