Envil CLI

Generate env.ts from .env.example and regenerate .env.example from env.ts using schema introspection.

The envil CLI provides a two-way workflow between .env.example files and type-safe env.ts definitions:

• envil add env reads a .env.example, infers schemas from values, and writes an env.ts file.
• envil add example imports your env.ts, introspects the schemas, and regenerates .env.example.

No manifest or metadata comments are needed in the generated code. The schemas themselves carry all the information required for round-tripping.

envil add env

Generates an env.ts file from a .env.example.

envil add env [options]

Options:

How inference works

Every assigned value in .env.example is used for two things:

1. Type inference — the value determines which schema to use (e.g. 3000 on a PORT key becomes port, true becomes boolean, a URL becomes url).
2. Default value — the value is wrapped in withDefault(schema, value) in the generated code, so the variable is optional at runtime.

For example, this .env.example:

# @server
PORT=3000
DATABASE_URL=postgres://user:pass@localhost:5432/app

# @client
NEXT_PUBLIC_API_URL=https://example.com

Generates:

import { createEnv, postgresUrl, port, url, withDefault } from "@ayronforge/envil";

export const envDefinition = {
  prefix: {
    server: "",
    client: "",
    shared: "",
  },
  server: {
    DATABASE_URL: withDefault(postgresUrl, "postgres://user:pass@localhost:5432/app"),
    PORT: withDefault(port, 3000),
  },
  client: {
    NEXT_PUBLIC_API_URL: withDefault(url, "https://example.com"),
  },
  shared: {
  },
} as const;

export const env = createEnv(envDefinition);

Inference rules

You can override inference using directives.

envil add example

Regenerates a .env.example from an existing env.ts file using schema introspection. It dynamically imports your env.ts, reads the envDefinition export, and walks the Effect Schema AST to extract type information, defaults, and wrapper metadata.

envil add example [options]

Options: