Getting Started

This guide walks you through installing Hedystia and creating your first typed server.

Prerequisites

Hedystia requires Bun as its runtime. If you haven't installed it yet:

curl -fsSL https://bun.sh/install | bash

Installation

Create a new project and install the required packages:

mkdir my-api && cd my-api
bun init -y
bun add hedystia

To use the typed client in a separate project or package:

bun add @hedystia/client

Your First Server

Create an index.ts file:

import Hedystia, { h } from 'hedystia'

const app = new Hedystia()
  .get('/', () => ({ message: 'Hello from Hedystia!' }), {
    response: h.object({ message: h.string() }),
  })
  .listen(3000)

console.log('Server running at http://localhost:3000')

Run the server:

bun run index.ts

Visit http://localhost:3000 — you should see:

Response

{
  "message": "Hello from Hedystia!"
}

Adding a Route with Params

import Hedystia, { h } from 'hedystia'

const app = new Hedystia()
  .get(
    '/users/:id',
    ({ params }) => {
      return { id: params.id, name: 'Jane Doe' }
    },
    {
      params: h.object({ id: h.number().coerce() }),
      response: h.object({
        id: h.number(),
        name: h.string(),
      }),
    }
  )
  .listen(3000)

The h.number().coerce() call tells Hedystia to coerce the URL param (which arrives as a string) into a number before passing it to the handler.

Adding a POST Route

import Hedystia, { h } from 'hedystia'

const app = new Hedystia()
  .post(
    '/users',
    ({ body }) => {
      return { id: 1, name: body.name, email: body.email }
    },
    {
      body: h.object({
        name: h.string(),
        email: h.string().email(),
      }),
      response: h.object({
        id: h.number(),
        name: h.string(),
        email: h.string(),
      }),
    }
  )
  .listen(3000)

Using the Client

Once your server is running, create a client with full type inference:

import { createClient } from '@hedystia/client'
import type { app } from './server'   // import just the type

const client = createClient<typeof app>('http://localhost:3000')

// POST /users
const { data, error } = await client.users.post({
  body: { name: 'Alice', email: 'alice@example.com' },
})

console.log(data?.name)  // 'Alice'

The client proxy mirrors your route structure. Nested paths map to chained properties, dynamic params become function calls.

Next Steps

• Routing — full guide to HTTP routes, params, and groups
• Context — everything available inside a handler
• Validation — the h schema reference
• Error Handling — typed errors and custom responses