ky hooks

Because fetcher delegates to ky, hook-based patterns stay familiar. The extra context.openapi metadata makes route-level instrumentation easier.

const api = createFetcher<paths>({
  prefixUrl: '/api',
  hooks: {
    beforeRequest: [
      (request, options) => {
        request.headers.set('x-client', 'web');
        console.debug('request', {
          method: options.context.openapi?.method,
          template: options.context.openapi?.pathTemplate,
        });
      },
    ],
    afterResponse: [
      (_request, options, response) => {
        reportMetric('http.response', {
          path: options.context.openapi?.pathTemplate,
          status: response.status,
        });
      },
    ],
  },
});

Auth clients

Create a base client once, then use extend for authenticated branches.

const api = createFetcher<paths>({ prefixUrl: '/api' });

export function withToken(token: string) {
  return api.extend({
    headers: {
      Authorization: `Bearer ${token}`,
    },
  });
}

extend returns a typed fetcher, so route inference remains available after composition.

ky hooks

Auth clients

On this page