# Setup

Install `@ideal-postcodes/sdk`, then create a client with your API key. The SDK runs in browsers and Node.js 22 or later and uses the runtime's native `fetch`.

## How do I create a client?

Install the package, then pass your API key to `createIdpcClient`.

```bash
npm install @ideal-postcodes/sdk
```

client.tsts

```ts
import { createIdpcClient } from "@ideal-postcodes/sdk";

const client = createIdpcClient({ apiKey: "ak_test" });
```

## Which client options are there?

`createIdpcClient` takes one required option and three optional ones.

| Option      | Type           | Purpose                                                       |
| ----------- | -------------- | ------------------------------------------------------------- |
| `apiKey`    | `string`       | Required API key, sent as `api_key`                           |
| `userToken` | `string`       | Management Key for account operations. Keep it on your server |
| `baseUrl`   | `string`       | Defaults to `https://api.ideal-postcodes.co.uk/v1`            |
| `fetch`     | `typeof fetch` | Custom fetch implementation for tests or request handling     |

## When do I need a Management Key?

Set `userToken` to a Management Key only to call the account operations that need it: key details, usage and logs, licensees and configs. Each [operation page](/docs/sdks/typescript/endpoints/.md) says whether it needs one. A Management Key controls your account, so keep it on your server and never use it in a client that runs in the browser. The SDK sends it in the `Authorization` header, and only to operations that accept it.

## Does the SDK need other packages?

No. The root package has no runtime dependencies. Install `@tanstack/react-query` or `@tanstack/preact-query` only when using the matching [adapter](/docs/sdks/typescript/react.md#how-do-i-use-tanstack-query).

## Does it support CommonJS?

Yes. CommonJS consumers can use `require("@ideal-postcodes/sdk")`, though only ESM imports tree-shake. TypeScript consumers can use either NodeNext or bundler module resolution.