---
title: Code Generation & Compiler Pipeline
description: How the Nooh compiler processes your project and transforms files into code.
---

Nooh is powered by a high-performance compiler (`@nooh-ts/compiler`) that transforms filesystem routes and containers into native Hono handlers.

## Compilation Pipeline

The compiler follows a 5-stage pipeline:

```mermaid
flowchart LR
    A[1. Discover] --> B[2. Parse]
    B --> C[3. Analyze]
    C --> D[4. Plan]
    D --> E[5. Generate]
```

### 1. Discovery (`discover`)
Scans your `routes/` and `dependencies/` folders from the filesystem or in-memory source snapshots. Discovers all `.ts` endpoint files and `group.ts` group configurations.

### 2. Parsing (`parse`)
Analyzes filenames to determine:
- HTTP method (e.g. `.get.ts`, `.post.ts`).
- URL segment types (static segments, `[param]` dynamic segments, `[...splat]` catch-all segments).
- Group hierarchies and nesting.

### 3. Analysis (`analyze`)
- Builds the complete dependency graph.
- Runs cycle detection algorithms (`NOOH023`).
- Validates dependency scope hierarchy (prevents singletons from capturing request-scoped dependencies).
- Checks for duplicate route definitions or naming collisions.

### 4. Planning (`plan`)
Determines the minimal set of output files needed in `.nooh/` and generates an execution plan.

### 5. Generation (`generate`)
Renders TypeScript code for:
- `.nooh/app.ts`: Root Hono router instance.
- `.nooh/router/**/*.ts`: Route-specific helper functions with strong typing.
- `.nooh/router/middleware.ts`: Middleware type utilities.

## Bundler Integration (Unplugin)

Nooh provides `@nooh-ts/plugin`, an [unplugin](https://github.com/unjs/unplugin) implementation compatible with Vite, Rollup, Webpack, and esbuild.

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

export default defineConfig({
  plugins: [
    nooh({
      config: "nooh.config.ts",
      outputRoot: ".nooh",
    }),
  ],
});
```

The plugin automatically hooks into your build tool's file watcher, rebuilding changed routes whenever you save a file.