Requests

Two helpers for things every admin ends up needing on the way out.

Contextual headers

A tenant, a branch, a workspace — a value that is not known when the axios instance is built, and that only belongs on some routes.

import { createHeaderInterceptor } from '@arex95/phalanx';

const stop = createHeaderInterceptor({
    header: 'X-Branch-ID',
    value: () => activeBranch.value?.uuid,
    match: /\/admin\//,
    exempt: [/\/admin\/users\/me(\/|$|\?)/]
});

Option
header	header name
value	read on every request, so it follows a ref
match	RegExp or predicate over the resolved URL; omitted, all requests
exempt	exceptions to match
instance	defaults to the instance the plugin configured

A null, undefined or empty value leaves the request untouched, which is the behaviour you want before the value is known.

The returned function ejects the interceptor. Registering twice sends the header twice, so keep the handle where the caller can run more than once.

Idempotency keys

A double-clicked submit, or a retry after a timeout, reaches the API as two requests. An idempotency key lets the server recognise the second as the same operation.

import { useIdempotencyKey, IDEMPOTENCY_HEADER } from '@arex95/phalanx';

const idem = useIdempotencyKey({ scope: 'appointment-create' });

await AppointmentService.create({
    data,
    headers: { [IDEMPOTENCY_HEADER]: idem.ensure() }
});

idem.rotate();   // the next appointment is a new operation

ensure()	the current key, generating one on first call
rotate()	discards it and returns a new one — call after a success
clear()	forgets it
key	Ref<string | null>

The key is kept in sessionStorage under the given scope, so a reload mid-submission reuses it rather than creating a second resource. Pass persist: false for a key that should not outlive the page.

Storage that throws — private mode, a browser blocking site data — degrades the guarantee to "unique per page load" rather than failing the call.

generateIdempotencyKey() is exported for code that manages its own keys.