# Header Checking

The header checker manager is part of the checker component (`web-token/jwt-checker`).

`spomky-labs/jose` and this framework works a similar way thus migration is very easy. The main differences are:

* There are two managers: one for the claims, one for the headers.
* The manager needs at least one Token Support handler.

You will find `JWS` and `JWE` Token Supports in the `web-token/jwt-signature` and `web-token/jwt-encryption` components respectively.

Checkers must implement the `Jose\Component\Checker\HeaderChecker` interface.

**Before**

```php
<?php

use Jose\Checker\CheckerManager;
use Jose\Checker\AudienceChecker;
use Jose\Checker\CriticalHeaderChecker;

$checkerManager = new CheckerManager();
$checkerManager->addHeaderChecker(new AudienceChecker('My Server'));
$checkerManager->addHeaderChecker(new CriticalHeaderChecker());

$checkerManager->checkJWS($jws, $signature_index);
```

**After**

```php
<?php

use Jose\Component\Checker\AudienceChecker;
use Jose\Component\Checker\HeaderCheckerManager;
use Jose\Component\Signature\JWSTokenSupport;

$checkerManager = new HeaderCheckerManager();
$checkerManager->add(new AudienceChecker('My Service'));
$checkerManager->addTokenTypeSupport(new TokenSupport());
```

*Please note that the header* `crit` *is always checked.*


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://web-token.spomky-labs.com/1.x/migration/from-spomky-labs-jose/header-checking.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.