Headers

Requests assemble headers from multiple sources before sending:

1. Driver defaults (global headers set on the driver)
2. Request headers returned by requestHeaders()
3. Body headers from the request body factory (e.g., Content-Type)

Later sources override earlier ones. Header values can be strings or callbacks that resolve at send time.

Global Headers (Driver)

Set headers once when you configure the driver:

BaseRequest.setRequestDriver(new FetchDriver({
    headers: {
        'X-XSRF-TOKEN': () => getCookie('XSRF-TOKEN')
    },
}))

Per-Request Headers

Override requestHeaders() on a request to add headers per request:

import { type HeadersContract } from '@blueprint-ts/core/requests'

public override requestHeaders(): HeadersContract {
    return {
        Authorization: `Bearer ${this.accessToken}`
    }
}

Body Headers

Request body factories can set headers such as Content-Type. For example, JsonBodyFactory sets Content-Type: application/json.