FetchClient

A fetch wrapper to make authorized requests

Overview

The overwhelming majority of tokens are minted to make authenticated requests to resource servers. The FetchClient is a fetch wrapper to ease signing Request instances with an Authorization header.

Example

const fetchClient = new FetchClient(orchestrator);

const response = await fetchClient.fetch('/api/messages');
const data = await response.json();

// Do something with data...

Features

• Bearer token authorization
• DPoP token authorization (with dpop-nonce retry and caching)
• insufficient_user_authentication step-up authentication support
• 401 auto-retry
• 429 auto-retry with exponential backoff or retry-after header support

Extensibility

To change the default behavior or add additional capabilities, simply extend the FetchClient class:

export class MyFetchClient extends FetchClient {
  defaultHeaders = { 'foo': 'bar' };

  // Updates `429` retry delay to always be 1s
  protected getRetryDelay(response: Response, request: APIRequest): number {
    return 1000;
  }

  protected async processResponse(response: Response, request: APIRequest) {
    // Send analytics data to server
    await sendData(response);

    super.processResponse(response, request);
  }
}

See Also

class APIClient

A fetch wrapper to make authorized requests.

abstract class TokenOrchestrator

Bridging the gap between user credentials and your application code.