Overview

tsgonest is a drop-in replacement for the NestJS build toolchain. It compiles your TypeScript via typescript-go, generates runtime validators and fast JSON serializers from your types, and produces an OpenAPI 3.2 document — all in a single tsgonest build command.

Why tsgonest?

NestJS projects typically rely on a stack of runtime libraries — class-validator, class-transformer, @nestjs/swagger — each with its own decorators and manual synchronization. Types defined once in TypeScript get re-declared across these layers.

tsgonest eliminates that. Write plain TypeScript types and everything else is generated at compile time:

import { Min, Max, Email, Trim } from '@tsgonest/types';

export interface CreateUserDto {
  name: string & Trim & Min<1> & Max<255>;
  email: string & Email;
  age: number & Min<0> & Max<150>;
}

Run tsgonest build and you get:

• Compiled JavaScript (~10x faster than tsc)
• Companion files with validate, assert, and serialize functions
• Controllers with injected validation and serialization (zero runtime setup)
• A complete OpenAPI 3.2 document

No decorators on every property. No reflect-metadata. No runtime overhead.

What it replaces

Two ways to define constraints

JSDoc tags (zero dependencies)

export interface CreateUserDto {
  /** @minLength 1 @maxLength 255 */
  name: string;

  /** @format email */
  email: string;

  /** @minimum 0 @maximum 150 */
  age: number;
}

Branded phantom types (type-safe, with autocomplete)

import { Min, Max, Email, Trim } from '@tsgonest/types';

export interface CreateUserDto {
  name: string & Trim & Min<1> & Max<255>;
  email: string & Email;
  age: number & Min<0> & Max<150>;
}

Both approaches generate identical code. Branded types give you IDE autocomplete and compile-time checking of constraints.

Performance

Measured on Apple Silicon, Node.js 25:

Packages

Next steps