Fetch middleware for adding default headers to outgoing requests.
Sets default headers on outgoing requests using the standard Headers API. Request headers take precedence over middleware headers. Supports both plain objects and Headers instances. Header names are case-insensitive per HTTP specification.
Intended for use with @qfetch/core.
npm install @qfetch/middleware-headers
import { withHeaders } from '@qfetch/middleware-headers';
import { withBaseUrl } from '@qfetch/middleware-base-url';
import { withAuthorization } from '@qfetch/middleware-authorization';
import { compose } from '@qfetch/core';
// Build an API client with default headers for JSON communication
const api = compose(
withHeaders({
'Content-Type': 'application/json',
'Accept': 'application/json',
'X-Client-Version': '1.0.0',
}),
withBaseUrl('https://api.example.com/v1/'),
)(fetch);
// All requests include the default headers
await api('users', {
method: 'POST',
body: JSON.stringify({ name: 'Alice' }),
});
For complete API reference, examples, and type definitions, see the API documentation.