401 Unauthorized with correct jwt token problem

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After login API I used 3 other APIs with jwt token coming from login API but one of the APIs returned an unauthorized error and my app stopped the login process.

I first thought the token was not properly set but then I copied the curl of that API and hit it in Postman it successfully returned.
this doesn’t come with same API every time for ex:

case 1
LOGIN API: SUCCESS
SOME API: 401

case 2
LOGIN API: SUCCESS
SOME API: SUCCESS
SOME OTHER API: 401

case 3
LOGIN API: SUCCESS
SOME API: SUCCESS
SOME OTHER API: SUCCESS
SOME OTHER API 2: 401

it only happens with api that runs continuously after login API.

It only occurs 1 out 5 times and 401 can be returned from any of 3 APIs which hit just after login API.

I didn’t change anything on the server side and it started happening recently.
How can I fix it?

  • 1

    Kindly share code on how you setting up the token and how you are verifying it in other api’s, which would be helpful to figure out the problem.

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  • Could it be that the token is expired by the point that you’re making these calls?

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  • Could it be that you forgot async await somewhere in your logic?

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Troubleshooting intermittent issues like this can be challenging, but here are some steps you can take to investigate and potentially resolve the problem:

  1. Token Expiry and Refresh:

    • Verify that the JWT token you receive after the login API call is not expired when you use it for subsequent API calls.
    • Check if the APIs that return a 401 error have a shorter expiration time for their tokens.
    • Implement token refresh mechanisms if needed.

  2. Token Handling:

    • Ensure that you are correctly including the token in the headers of subsequent API requests.
    • Check for any differences in how the token is handled for the APIs that succeed and the ones that return a 401.

  3. API Rate Limiting:

    • Some APIs implement rate limiting. If you’re making a high volume of requests, you may hit rate limits and receive a 401 error. Check the API documentation for rate limits.

  4. Server-Side Logs:

    • Examine server-side logs for the APIs that return a 401 status code. Look for any error messages or patterns that might indicate the cause.

  5. Retry Mechanism:

    • Implement a retry mechanism for the API calls that return a 401 status code. This might help in cases where the issue is transient.

  6. Check for Server-Side Changes:

    • Even if you haven’t made changes on your end, check if there have been any updates or changes on the server side. Sometimes, changes on the server can affect the behavior of your API calls.

  7. Network Issues:

    • Intermittent network issues can also cause such problems. Check for any network-related problems between your application and the API server.

  8. Error Handling:

    • Review your error-handling mechanisms to ensure that your application gracefully handles errors, retries when appropriate, and provides meaningful feedback to users.

  9. Update Dependencies:

    • Ensure that your dependencies (libraries, frameworks, etc.) are up-to-date. Sometimes, issues can be related to outdated libraries.

  10. Contact API Provider:

    • If the issue persists, consider reaching out to the API provider’s support. They may have insights into any ongoing issues or changes on their end.

By systematically going through these steps, you may identify the root cause of the intermittent 401 errors and find a solution. If the issue persists, involving the API provider’s support can be beneficial.

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