One schema.
Full stack.

import { defineApi, endpoint, route } from '@cleverbrush/server/contract';
import { object, string, number, array } from '@cleverbrush/schema';

const User = object({
  id:    string().uuid(),
  name:  string().minLength(2),
  email: string().email(),
  age:   number().min(0).max(150)
});

export const api = defineApi({
  users: {
    list:   endpoint.get('/api/users').returns(array(User)),
    create: endpoint.post('/api/users')
              .body(object({ name: string(), email: string(), age: number() }))
              .returns(User),
    get:    endpoint
              .get('/api/users', route({ id: string() })`/${t => t.id}`)
              .returns(User)
  }
});

import { createServer, mapHandlers } from '@cleverbrush/server';
import { api } from './contract';

const server = createServer();

// mapHandlers gives a compile error if any endpoint is missing
mapHandlers(server, api, {
  users: {
    list:   async () => db.users.findAll(),
    create: async ({ body }) => db.users.insert(body),
    get:    async ({ params }) => db.users.findById(params.id)
    // ^ forget one? TypeScript error: Property 'get' is missing
  }
});

await server.listen(3000);

import { createClient } from '@cleverbrush/client';
import { api } from './contract';

const client = createClient(api, { baseUrl: 'http://localhost:3000' });

// Fully typed — no codegen, no manual annotations
const users = await client.users.list();
//    ^ User[]

const alice = await client.users.create({
  body: { name: 'Alice', email: 'alice@example.com', age: 30 }
});
//    ^ User — wrong shape is a compile error