OpenAPI to
in seconds.

Production-grade API infrastructure. Typed SDKs, Zod schemas, TanStack Query hooks, and 20+ plugins. Free and open source.

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from pydantic import BaseModel, AwareDatetime
from typing import Literal
from uuid import UUID

class Order(BaseModel):
    id: UUID
    symbol: str
    side: Literal['buy', 'sell']
    type: Literal['market', 'limit', 'stop', 'stop_limit']
    quantity: float
    price: float | None = None
    status: Literal['pending', 'open', 'filled', 'partially_filled', 'cancelled', 'rejected']
    createdAt: AwareDatetime

from client import Client, CreateOrderData

client = Client()

order, error = client.create_order(CreateOrderData(
    symbol='AAPL',
    side='buy',
    type='limit',
    quantity=10,
    price=189.50,
))

if error:
    print(f'Order failed: {error.message}')
else:
    print(f'Order placed: {order.id}')

Up and running in minutes

One config file. One command. Every time your spec changes.

01 / 04 Define your API

Define your API

Start with an existing spec or create one from scratch. OpenAPI is the foundation that powers everything.

openapi: 3.2.0
info:
  title: Equity Trading API
  version: 1.2.0
paths:
  /orders:
    post:
      operationId: createOrder
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Order'
      responses:
        '201':
          description: Order placed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Order'

Connect your spec

Pass a local path, remote URL, or an API registry shorthand. All valid OpenAPI versions and file formats supported, including inline spec objects.

export default defineConfig({
  input: 'https://api.tradespark.io/openapi.json',
  output: 'src/trading-client',
});

Compose your output

Choose exactly what gets generated – nothing more, nothing less. Each plugin is independent and composable.

export default defineConfig({
  input: 'https://api.tradespark.io/openapi.json',
  output: 'src/trading-client',
  plugins: ['@hey-api/sdk', 'zod', '@tanstack/react-query'],
});

Use it

Run once or integrate into CI. Generated code is fully typed and deterministic. Same spec, same output, every time.

import { createOrder, zOrder } from './trading-client';

const { data, error } = await createOrder({
  body: {
    symbol: 'AAPL',
    side: 'buy',
    type: 'limit',
    quantity: 10,
    price: 189.5,
  },
});

if (error) {
  console.error('Order rejected:', error.message);
  return;
}

const order = zOrder.parse(data);
console.log(`Order ${order.id} is ${order.status}`);

Everything your API layer needs

Pick what you need. Everything works together.

SDKs & Types

Typed SDK clients that regenerate as your API evolves. No handwritten interfaces to maintain.

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Plugin Ecosystem

From TanStack Query to Zod. Every plugin is opt-in, independently useful, and built to work together.

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HTTP Clients

Native support for your runtime. Fetch API, Axios, Angular, Next.js, Nuxt, and more.

Explore clients →

Extensibility

Build custom plugins and clients with the same APIs powering the built-ins. A platform, not a black box.

Build a plugin →

The standard for API tooling.

Every API tool forces a trade-off: quality, workflow, cost, or speed. Often more than one. I wanted to know what happens when you refuse to compromise.
Hey API was built with one goal in mind: to be the last code generator you will ever need. Purpose-built from scratch, held to the standard the best engineering teams apply to their own codebase.
The result of that work is yours, one install away.

Honest take

Not the right fit if…

Your spec is broken or out of date.
You're building a one-off integration, not a long-term API contract.
You already have a codegen workflow that works.
You want zero build steps.
We don't support your language yet.

If none of these apply, you'll probably love it.

Coming soon

Python is next.

The ecosystem trusted by TypeScript developers is coming to Python codebases. Production-grade SDKs, Pydantic models, and more. Sign up for early access.

Ready when you are.

Player 1 OpenAPI Spec READY

Player 2 Your Client READY?

Get Started → View on GitHub ↗