> ## Documentation Index
> Fetch the complete documentation index at: https://docs.typesafe.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# JavaScript SDK

JavaScript and TypeScript SDK for [TypeSafe AI](https://typesafe.ai).

## Quickstart

Install the SDK (Node.js 20 or newer):

```sh theme={null}
npm install @typesafe-ai/sdk
```

Set `TYPESAFE_API_KEY` in your environment, then create and use the client:

```ts theme={null}
import { choice, TypeSafeClient } from "@typesafe-ai/sdk";

const client = new TypeSafeClient();
const response = await client.systemOne({
  state: { document: "I was charged twice. Please fix this ASAP." },
  questions: {
    category: choice("What is this ticket about?", {
      billing: null,
      technical: null,
      other: null,
    }),
  },
});

console.log(response.answers.category.choice);
```

Answer types are inferred from your questions. The package includes ESM, CommonJS, and TypeScript declarations.

## Documentation

Learn what TypeSafe can do in the [TypeSafe docs](https://docs.typesafe.ai/).
See the SDK's [client](https://github.com/typesafe-ai/typesafe-sdk-js/blob/v0.5.7/src/client.ts) and [types](https://github.com/typesafe-ai/typesafe-sdk-js/blob/v0.5.7/src/types.ts) for API options and defaults.