Built-in Schemas

Reference for string, number, URL, boolean, and parsed environment schemas.

All built-in schemas are Effect Schemas and may be used directly in a server or client fragment:

const appEnv = createEnv(
  server({
    PORT: port,
    DATABASE_URL: redacted(postgresUrl),
  }),
);

Strings

Name	Type	Default	Description
requiredString	string	—	A present, non-empty string.

Use optional(schema) when absence is valid.

Numbers

Name	Type	Default	Description
number	number	—	Any number parsed from a string.
positiveNumber	number	—	A number greater than zero.
integer	number	—	A whole number.
nonNegativeNumber	number	—	A number greater than or equal to zero.
port	number	—	A whole number from 1 through 65535.

values: {
  PORT: port,
  MAX_RETRIES: integer,
  RATE_LIMIT: positiveNumber,
  THRESHOLD: number,
}

Boolean

Name	Type	Default	Description
boolean	boolean	—	Parses true, false, 1, or 0 without case sensitivity.

values: {
  DEBUG: boolean,
}

URLs

Name	Type	Default	Description
url	string	—	HTTP or HTTPS URL.
postgresUrl	string	—	PostgreSQL connection URL.
redisUrl	string	—	Redis connection URL.
mongoUrl	string	—	MongoDB connection URL.
mysqlUrl	string	—	MySQL connection URL.
commaSeparatedUrls	string[]	—	Comma-separated HTTP and HTTPS URLs.

Server connection URLs should normally be redacted:

values: {
  DATABASE_URL: redacted(postgresUrl),
  REDIS_URL: redacted(redisUrl),
  WEBHOOK_URL: url,
}

Comma-separated values

Name	Type	Default	Description
commaSeparated	string[]	—	Trimmed strings separated by commas.
commaSeparatedNumbers	number[]	—	Numbers separated by commas.

values: {
  ALLOWED_ORIGINS: commaSeparated,
  RETRY_DELAYS: commaSeparatedNumbers,
}

Parameterized schemas

`stringEnum`

values: {
  LOG_LEVEL: stringEnum(["debug", "info", "warn", "error"]),
}

`json`

import { Schema } from "effect";

values: {
  JSON_CONFIG: json(
    Schema.Struct({
      retries: Schema.Number,
      timeout: Schema.Number,
    }),
  ),
}

Effect Schema

Effect Schemas with context requirements are accepted. Schema outputs must not be functions:

values: {
  NODE_ENV: Schema.Literal("development", "production", "test"),
  API_KEY: Schema.String.check(Schema.isMinLength(32)),
}

Tip

Use Effect Schema directly when the built-in set does not express the desired validation and decoded type. Its errors and context requirements are preserved by the resulting environment Effect.