Laravel + Passport - why does "auth:api" send me to login form?

Using Laravel (5.4) + Passport (4.0) I am trying to implement an oAuth authorization for my api. Getting the token is no problem, but as soon I access the wanted ressource at http://somedomain.tld/api/user I get somehow tossed to the web login form. My request holds all necessary headers as:

[{"key":"Authorization","value":"Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImp0aSI6ImYxODk3ZmVhODIyOGQ0ZGY5MzU0ODI3NThiZTdlMmU0NTVjN2NkMzExMjc5OTdhMzU3NTQ3ZDQ5NzhhYTVmNjdjMTc5NmVlNTVjZGE4OTIyIn0.eyJhdWQiOiIxIiwianRpIjoiZjE4OTdmZWE4MjI4ZDRkZjkzNTQ4Mjc1OGJlN2UyZTQ1NWM3Y2QzMTEyNzk5N2EzNTc1NDdkNDk3OGFhNWY2N2MxNzk2ZWU1NWNkYTg5MjIiLCJpYXQiOjE1MDQxMTAzNzMsIm5iZiI6MTUwNDExMDM3MywiZXhwIjoxNTA1NDA2MzczLCJzdWIiOiIiLCJzY29wZXMiOltdfQ.WadULiSlQBJtG2Ixag8kGyI82UdXxHBGRWVJEb6ro4HGKPMpDl6-SRkp0EPV8ZJN2fZpv43g-bkJc-xVqPPHgx42QmDacOWeBcEb4kT5lYR6H540F_VmVUkB7ZRxNeEhX3cXysNmwRxrdbEvks3ml5S6pT1SSh2iDvYVk3xeAFhXv6GNBuy_3IOxaRwa9svXH7fR8n1YoJub8dnJM9xoGgXaxGFUoddjYMJNDjE7WYFHKePYES4ovp74OnPngJp62864kQ-8MEZmMaPPYmRX9SmSei-9VmWrdo5c9MyDBIDNgZpFF34bfA843LzSqgz1qDf26msjJX28tbP70fmNa1k5vt2OSYWVIB-G3eH280357VZbcbFmL34SqoAUOaWNjrLGPajBeVtqQO1sLW0y_662-b5ei3X4aZgDv09cfmll5IvkH1qsPYoB3ieBVkI8Fpet6T0p2-0iQjW9tClhGATlBMpEI67FIVBOFxw37YBmJSuj76XCd4MV0KVizWtLKpQZrYw64Kr9ncRMVf2fEsdUMZ6XahPBioTsC_CEkf9EgSBjKM-6l6P5C0yM51IbbUpjsjTZcfpzavuSDyOkrg2B_oSU9u_a2oX_K2NQyERxvsmJgkmV5FWol84GaNgPQZHOSekwdI52EobMAMFBapgjWVqjvhLagazWFsK9crI","description":""},{"key":"Content-Type","value":"application/json","description":""}]

[{"key":"Accept-Encoding","value":"application/json","description":""}]

[{"key":"Accept-Encoding","value":"application/json","description":""}]

my routes/api.php reads

Route::get('/user', function (Request $request) {
    return $request->user();
})->middleware('auth:api');

but somehow I keep getting sent to the web login form. Anyone who can explain me? I already posted a more detailed question with all sourcecode here.

Solution

Use these headers while requesting through AJAX, jQuery handles this automatically for you but for other frameworks it needs to be done manually.

X-Requested-With: XMLHttpRequest