Install

Nestia runs on TypeScript 7 through ttsc. Install the compiler toolchain, the runtime packages, and the CLI explicitly:

npm i -D ttsc typescript
npm i typia @nestia/core @nestia/sdk @nestia/fetcher
npm i -D nestia

pnpm i -D ttsc typescript
pnpm i typia @nestia/core @nestia/sdk @nestia/fetcher
pnpm i -D nestia

yarn add -D ttsc typescript
yarn add typia @nestia/core @nestia/sdk @nestia/fetcher
yarn add -D nestia

bun add -d ttsc typescript
bun add typia @nestia/core @nestia/sdk @nestia/fetcher
bun add -d nestia

@nestia/sdk is a runtime dependency. The generated SDK and runtime Swagger composition both resolve it while the Nestia transform attaches route metadata.

tsconfig.json

Keep the NestJS decorator metadata flags. Do not add compilerOptions.plugins for normal Nestia setup; ttsc discovers @nestia/core, @nestia/sdk, and typia from their package manifests.

{
  "compilerOptions": {
    "strict": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}

Transform options

No plugin config means Nestia uses its defaults:

• @TypedBody validates with "validate".
• @TypedRoute serializes with "assert".
• LLM schema restrictions are off.

Add compilerOptions.plugins only when you want to override those options:

{
  "compilerOptions": {
    "plugins": [
      { "transform": "typia/lib/transform", "enabled": false },
      {
        "transform": "@nestia/core/native/transform.cjs",
        "validate": "validatePrune",
        "stringify": "validate.log",
        "llm": { "strict": true }
      }
    ]
  }
}

If a nest new project has tsconfig.build.json, point ttsc at that file so test files stay out of production output:

{
  "scripts": {
    "build": "ttsc -p tsconfig.build.json"
  }
}

Build

Replace NestJS CLI build commands with ttsc / ttsx.

{
  "scripts": {
    "build": "ttsc",
    "start": "node dist/main.js",
    "start:dev": "concurrently \"ttsc --watch\" \"node --watch dist/main.js\"",
    "start:script": "ttsx src/main.ts"
  }
}

nest build, nest start, tsc, ts-node, and tsx do not run the Nestia transform. Use ttsc for builds and ttsx for direct TypeScript execution.

Generate

Create nestia.config.ts once, then run the generators:

npx nestia init
npx nestia sdk
npx nestia swagger
npx nestia e2e
npx nestia all

init writes a starter config. sdk, swagger, and e2e emit one artifact each; all runs the three together.

Bundlers

A normal NestJS server should compile with ttsc directly. When a bundler owns the build, install @ttsc/unplugin and add the adapter for that bundler.

npm i -D @ttsc/unplugin

pnpm i -D @ttsc/unplugin

yarn add -D @ttsc/unplugin

bun add -d @ttsc/unplugin

import ttsc from "@ttsc/unplugin/vite";
import { defineConfig } from "vite";
 
export default defineConfig({
  plugins: [ttsc()],
});

Use the matching import path for other bundlers: @ttsc/unplugin/webpack, @ttsc/unplugin/rspack, @ttsc/unplugin/esbuild, @ttsc/unplugin/next, @ttsc/unplugin/rollup, @ttsc/unplugin/rolldown, @ttsc/unplugin/farm, or @ttsc/unplugin/bun.

Troubleshooting

• no transform has been configured: the project was built by tsc, nest build, SWC, Babel, or another path that skipped ttsc.
• Empty SDK or Swagger output: confirm the controllers use @TypedRoute and that the generator reads the same tsconfig.json as the build.
• NestJS DI fails: restore experimentalDecorators and emitDecoratorMetadata; NestJS still needs them for constructor injection.
• Bundler output skips validation: add the matching @ttsc/unplugin adapter to the bundler config.