---
title: Configuration Reference
description: Complete specification for nooh.config.ts and group.ts configuration files.
---

Nooh projects are configured via TypeScript configuration files.

## `nooh.config.ts`

The top-level configuration file defines project-wide settings, typed environment bindings, and global error handlers.

```ts nooh.config.ts
import { config } from "@nooh-ts/nooh";

export interface AppEnv {
  Bindings: {
    DATABASE_URL: string;
    JWT_SECRET: string;
  };
  Variables: {
    userId?: string;
  };
}

export default config<AppEnv>({
  routes: "src/routes",
  dependencies: "src/dependencies",
  onError: (error, c) => {
    return c.json({ error: error.message }, 500);
  },
  validator: {
    // Optional validator engine configuration
  },
});
```

### Options

| Option | Type | Default | Description |
| :--- | :--- | :--- | :--- |
| `routes` | `string` | `"src/routes"` | Path to the directory containing route endpoint files. |
| `dependencies` | `string` | `"src/deps"` | Path to the directory containing DI containers. |
| `onError` | `NoohErrorHandler<Env>` | `undefined` | Global error handler for uncaught exceptions across all routes. |
| `validator` | `NoohValidatorOptions` | `undefined` | Custom options and engine configuration for Standard Schema validator. |

---

## `group.ts`

Each directory inside `routes/` can optionally include a `group.ts` file to configure route groups, scoped middleware, and localized error handlers.

```ts src/routes/admin/group.ts
import { group } from "@nooh-ts/nooh";
import { adminAuthMiddleware } from "@/middleware/admin";

export default group({
  middleware: [adminAuthMiddleware],
  onError: (error, c) => {
    return c.json({ section: "admin", error: error.message }, 500);
  },
});
```

### Options

| Option | Type | Default | Description |
| :--- | :--- | :--- | :--- |
| `middleware` | `readonly MiddlewareHandler[]` | `[]` | List of middleware functions applied to all routes in this group and sub-groups. |
| `onError` | `NoohErrorHandler<Env>` | `undefined` | Scoped error handler for all routes in this directory and sub-directories. |