authentication.md

Authentication Middleware

Adds an authentication header to matching requests.

Usage

import { FetchClient } from '@fgrzl/fetch';
import { addAuthentication } from '@fgrzl/fetch/middleware/authentication';

const client = addAuthentication(new FetchClient(), {
  tokenProvider: () => localStorage.getItem('auth-token') || '',
});

By default, a token is sent as Authorization: Bearer <token>.

Options

interface AuthenticationOptions {
  tokenProvider: () => string | Promise<string>;
  headerName?: string;
  tokenType?: string;
  skipPatterns?: (RegExp | string)[];
  includePatterns?: (RegExp | string)[];
  requireToken?: boolean;
}

• tokenProvider: returns the token.
• headerName: header to set. Default is Authorization.
• tokenType: token prefix. Default is Bearer.
• skipPatterns: paths that should not receive auth.
• includePatterns: when provided, only matching paths receive auth.
• requireToken: return a synthetic 401 response when no token is available.

API Key Example

const client = addAuthentication(new FetchClient(), {
  tokenProvider: () => getApiKey(),
  headerName: 'X-API-Key',
  tokenType: 'ApiKey',
});

Required Token Example

const client = addAuthentication(new FetchClient(), {
  tokenProvider: () => sessionStorage.getItem('token') || '',
  requireToken: true,
});

const response = await client.get('/private');

if (!response.ok && response.status === 401) {
  showLogin();
}