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

# Token sources

> Supply static or dynamically-refreshed API tokens to the SDK.

`AmikaClient` needs a bearer token for every request. You provide it in one
of two ways: a static `accessToken`, or a `tokenSource` that the client
calls each time it needs a token. They're mutually exclusive.

## Static token

The simplest case — pass a token string you already have.

```ts theme={null}
import { AmikaClient } from "@amika/sdk";

const amika = new AmikaClient({
  baseUrl: "https://app.amika.dev",
  accessToken: process.env.AMIKA_API_KEY!,
});
```

## The `TokenSource` interface

For tokens that need to be fetched or refreshed, implement `TokenSource`:

```ts theme={null}
interface TokenSource {
  token(): string | Promise<string>;
}
```

The client calls `token()` to obtain a bearer for requests. Returning a
promise lets you fetch or refresh on demand.

## `StaticTokenSource`

A ready-made `TokenSource` that always returns the same token. Equivalent to
passing `accessToken`, but useful when an API expects a `TokenSource`.

```ts theme={null}
import { AmikaClient, StaticTokenSource } from "@amika/sdk";

const amika = new AmikaClient({
  baseUrl: "https://app.amika.dev",
  tokenSource: new StaticTokenSource(process.env.AMIKA_API_KEY!),
});
```

## A refreshing token source

Implement `TokenSource` yourself when tokens expire and need refreshing.
The client awaits `token()` on each request, so you can cache and refresh
inside it.

```ts theme={null}
import { AmikaClient, TokenSource } from "@amika/sdk";

class RefreshingTokenSource implements TokenSource {
  private cached?: { token: string; expiresAt: number };

  async token(): Promise<string> {
    if (!this.cached || Date.now() >= this.cached.expiresAt - 60_000) {
      const fresh = await fetchTokenFromYourAuthService();
      this.cached = { token: fresh.token, expiresAt: fresh.expiresAtMs };
    }
    return this.cached.token;
  }
}

const amika = new AmikaClient({
  baseUrl: "https://app.amika.dev",
  tokenSource: new RefreshingTokenSource(),
});
```

<Note>
  The SDK never reads `AMIKA_API_KEY` from the environment or disk on your
  behalf. Sourcing the token — from an env var, a secret manager, or an auth
  service — is always the caller's responsibility.
</Note>