KatanaKit ships a Bun-native server adapter (katanakit-js/adapters/bun) built on Bun.serve with the modern routes API (Bun v1.2.3+). It's a drop-in alternative to the Express adapter for Bun projects — no Express, no middleware chain, just a typed route table.

Install

bun add katanakit-js

Add bun-types to your tsconfig.json types for the Bun global:

{
  "compilerOptions": {
    "types": ["bun-types"]
  }
}

Quick start

bun run dev:bun boots the dummyjson demo server:

bun run dev:bun
# Server running at http://localhost:3000

import { defineApiConfig } from "katanakit-js";
import { dummyJsonApiConfig, useBunStart } from "katanakit-js/adapters/bun";

defineApiConfig(dummyJsonApiConfig);

const server = useBunStart(3000);
console.log(`Server running at ${server.url}`);

The route table

useBuildDummyJsonRoutes() returns a typed Bun.serve route table. Handlers are pure and return Response — they reuse the core useFetch with the Safe Result pattern.

import { useBuildDummyJsonRoutes } from "katanakit-js/adapters/bun";

Bun.serve({
  routes: useBuildDummyJsonRoutes(),
  fetch: () => new Response("Not Found", { status: 404 }),
});

Route	Handler
GET /api/status	static JSON
GET /api/products	useDummyJsonProducts
GET /api/products/:id	useDummyJsonProductById
GET /api/products/search?q=	useDummyJsonProductSearch
GET /api/products/categories	useDummyJsonProductCategories
GET /api/products/category/:category	useDummyJsonProductsByCategory
GET /api/users, GET /api/users/:id	users
GET /api/posts, GET /api/posts/:id	posts
GET /api/quotes, GET /api/quotes/random	quotes
GET /api/seed	offline seed data
GET /api/*	404 catch-all

Direct handlers

You can use the handlers anywhere a Response is expected — no Bun router required:

import { defineApiConfig } from "katanakit-js";
import { dummyJsonApiConfig, useDummyJsonProducts } from "katanakit-js/adapters/bun";

defineApiConfig(dummyJsonApiConfig);
const response = await useDummyJsonProducts(); // Response with the product list

Seed data

import { useGetDummyJsonSeed } from "katanakit-js/adapters/bun";

const seed = useGetDummyJsonSeed();
seed.products; // [{ id, title, description, category, price, rating, stock, brand }]
seed.users;    // [{ id, firstName, lastName, username, email, age, role }]

Server facade

useBunCreate is a singleton — subsequent calls return the same server:

import { useBunCreate, useBunGetServer, useBunStop } from "katanakit-js/adapters/bun";

useBunCreate({ port: 3000, hostname: "localhost" });
useBunGetServer()?.url; // URL
await useBunStop();