Mandu vs Hono#

TL;DR — Hono is a router-as-library (~12 KB). Mandu is a full fullstack framework (router + React + build + Guard + MCP). They overlap on the API layer, but solve different problems beyond that.

When to pick which#

Side by side#

Code comparison — typed POST endpoint#

Hono with zod-validator:

import { Hono } from "hono";
import { zValidator } from "@hono/zod-validator";
import { z } from "zod";

const app = new Hono();

app.post(
  "/signup",
  zValidator("json", z.object({ email: z.string().email(), password: z.string().min(8) })),
  async (c) => {
    const body = c.req.valid("json");
    const user = await db.user.create({ data: body });
    return c.json({ id: user.id }, 201);
  },
);

export default app;

Mandu — contract-first, response shape also locked in:

// spec/contracts/signup.contract.ts
export const signupContract = Mandu.contract({
  request:  { POST: { body: z.object({ email: z.string().email(), password: z.string().min(8) }) } },
  response: { 201: z.object({ id: z.string() }), 400: z.object({ error: z.string() }) },
});

// app/api/signup/route.ts
export default Mandu.handler(signupContract, {
  POST: async (ctx) => ({ id: (await ctx.db.user.create({ data: ctx.body })).id }),
});

The Mandu version validates request and response, exports OpenAPI for free, and generates a typed client. The Hono version is shorter for a single endpoint but each subsequent endpoint repeats the wiring.

When Hono wins#

• Pure API service, no UI, no content. Mandu's UI/build layer is overhead you don't need.
• You target an edge runtime Mandu doesn't yet support first-class (Lagon, Fastly).
• Embedding into an existing app where minimal dependency footprint matters.

When Mandu wins#

• You need API + React UI + docs/content in one repo.
• You want one place to enforce architecture (FSD, Clean, Hexagonal — Guard ships 6 presets).
• AI agents are doing significant scaffolding and you want them constrained by contracts and Guard.

🤖 Agent Prompt — port a Hono service to Mandu#

I have a Hono API service and I'm evaluating moving it under Mandu
(https://mandujs.com) so I can add a React UI in the same repo.

1. Pick 3 representative routes from my Hono app.
2. For each, show me the Mandu equivalent — contract file +
   handler using Mandu.handler(contract, ...).
3. Map Hono middleware to Mandu's filling chain `.use(...)`.
4. Identify any Hono-specific features I lose (edge adapters,
   bundler tricks).
5. Estimate the percentage of routes that port cleanly vs need
   rewriting.

Related#

• start/quickstart
• recipes/create-api
• edge/ — Mandu edge runtime adapters