Laravel API works in Postman but returns 401 Unauthorized in React Native app

[solanerowe18-collab]

🏷️ Discussion Type

Question

Body

I'm building a mobile application using React Native and a Laravel REST API.

The API endpoints work correctly when I test them in Postman, but when I make the same request from my React Native application, I receive a 401 Unauthorized response.

Current setup:

• Laravel 12
• React Native
• Sanctum authentication
• MySQL database

What I've checked so far:

• API URL is correct
• User credentials are valid
• Token is being generated successfully
• Authorization header is being sent from the mobile app

Example request header:

Authorization: Bearer {token}
Accept: application/json

What are the most common reasons why a Laravel API works in Postman but returns 401 errors when called from a React Native application?

Any debugging suggestions would be appreciated.

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[maheerCodes]

hey @solanerowe18-collab 👋 .
"works in postman,fails in app" with a 401 on sanctum is a classic and almost always comes down to one of these :
most likely cause,,,token not actually being sent:
even when you think the Authorization header is going out ,,,double check by console.logging the actual axios /fetch config right before the request fires. specifically logconfig.headersnot just the token variable ,,, sometimes the header gets dropped silently if the token is undefined/ null at the time the request runs(async timing isssue ,,token not yet loaded from asyncstorage when the request fires) .

console.log('token:', token)
console.log('headers:', {
  Authorization: `Bearer ${token}`,
  Accept: 'application/json'
})

sanctum-specific things to check:

• make sure youre usingapi guard ,not webguard in laravel.sanctum has both,,,,sanctum token auth uses the api guard.check your config/auth.php and make sure the api guard is set to sanctum driver,
• in your route definition ,,, check if youre using auth:sanctum middleware specifically vs just auth,,,, they behave differently.
• make sure the token beingg sent was generated with the correct user and hasnt expired or been deleted,,,try revoking all tokens and generating a fresh one,then test immediately.

android-specific gotcha if youre testing on android:

• android blocks http (non-https)requests by default in newer versions ,, if your api url useshttp:// instead of https://on android,,, the request might silently fail or get modified.check your AndroidManifest.xml for android:usesCleartextTraffic setting.

quick debug step :
try adding \Log::info(request()->headers->all()) in your laravel controller to log exactly what headers are actually arriving at the server ,,, postman vs react native often sends subtly different header formats(capitalization, spacing) that can cause issues💙💙💙💙 .

[Amitabh-Phule]

Hi,

If the request works in Postman but returns 401 Unauthorized from React Native, the issue is usually related to authentication rather than the endpoint itself.

Some common things to check:

1. Verify the Authorization header is actually being sent.

For example:

Authorization: Bearer YOUR_TOKEN
Accept: application/json

You can inspect the outgoing request using React Native debugging tools or log the request configuration before sending it.

2. Confirm the token is stored and retrieved correctly.

A common issue is that the token is generated successfully during login but is not being saved correctly in AsyncStorage/Secure Storage, resulting in an empty or invalid token being sent.

3. Check for extra spaces or formatting issues.

For example:

Authorization: Bearer ${token}

Make sure the token does not contain leading/trailing whitespace.

4. Verify the API guard configuration.

If you are using Sanctum, ensure your protected routes are using the correct middleware and authentication guard.

5. Test the exact token from the mobile app in Postman.

Copy the token being used by React Native and try it in Postman. If it fails there as well, the token itself may be invalid or expired.

6. Check Laravel logs.

Look at:

storage/logs/laravel.log

There may be additional details explaining why the request is being rejected.

7. Verify token expiration and revocation.

Make sure the token has not expired or been revoked after login.

Could you share:

• The React Native request code
• The protected Laravel route definition
• The auth.php guard configuration

That would help narrow down the exact cause.