Getting 401 unauthorized error when exchanging auth code for Miro access token

Other Questions Miro
1

I’m working on integrating Miro’s OAuth flow into my application and running into issues during the token exchange process. Everything works fine up until I try to swap the authorization code for an access token. When I make the POST request to exchange the code, I keep getting a 401 unauthorized response even though I’m confident my client credentials are correct. I’ve double checked my client ID, client secret, and the authorization code multiple times. I’m following the standard OAuth2 flow where users first authorize my app, then I capture the code from the redirect URL, and finally attempt to exchange it for tokens. The authorization step works perfectly, but the token exchange fails consistently. Has anyone encountered similar authentication issues with Miro’s OAuth implementation? I’m wondering if there’s something specific about their API requirements that I might be missing. Any suggestions on what could be causing this 401 error would be really helpful.

2

miro’s oauth codes expire in like 10 mins, so if ur debuging for too long they go stale and throw 401s. also, double check the endpoint (/v1/oauth/token) and don’t mix up query params with post body params - i’ve done that b4 lol

3

Check your base64 encoding of the client credentials. I hit this exact issue - turns out I was formatting the Authorization header wrong. Make sure you’re doing Basic auth with client_id:client_secret properly base64 encoded. Also, Miro’s picky about the grant_type parameter - it has to be exactly ‘authorization_code’ in the POST body. Your auth code might’ve expired too (they don’t last long). I’d log your request headers and body, then compare them against Miro’s docs. Small formatting differences will break auth every time.

4

Been there with Miro’s OAuth. Those 401 errors are usually timing issues or parameter encoding problems - absolute pain to debug manually.

Had this exact headache last year building integrations. Wasted way too much time on headers, encoding, and token timing.

Automating the OAuth flow saved me. I use Latenode now to handle all token exchanges and refreshes. It automatically deals with encoding, timing, and headers.

You can set up the whole Miro OAuth workflow visually without wrestling with the technical stuff that causes 401s. Handles token storage and refresh cycles too.

Way less debugging, way more reliable than coding from scratch.

5

The Problem:

You’re receiving a 401 Unauthorized error when attempting to exchange an authorization code for an access token in Miro’s OAuth 2.0 flow. This typically means your application isn’t properly authenticating with Miro’s token endpoint.

:thinking: Understanding the “Why” (The Root Cause):

Miro’s OAuth 2.0 flow requires a three-legged authentication process. A 401 error at the token exchange stage usually points to problems with the request sent to the /v1/oauth/token endpoint. Common causes include:

  • Incorrect redirect_uri: The redirect_uri parameter in your token exchange request must exactly match the redirect URI configured in your Miro application. Even a single extra or missing character (like a trailing slash) will lead to a 401 error.
  • Improper URL Encoding: The authorization code received from the authorization server needs to be properly URL-encoded before being sent in the token exchange request.
  • Missing or Incorrect Headers: The request must include the correct Content-Type header (application/x-www-form-urlencoded).
  • Expired Authorization Code: Authorization codes in Miro have a limited lifespan (often around 10 minutes). If you’re debugging for an extended period, the code may expire, resulting in a 401 error.

:gear: Step-by-Step Guide:

  1. Verify the redirect_uri: Carefully compare the redirect_uri value used in your token exchange request against the redirect URI settings in your Miro application. Ensure they are identical, including case and trailing slashes.

  2. URL Encode the Authorization Code: Before including the authorization code (code) in your POST request to /v1/oauth/token, ensure it’s properly URL-encoded. Most programming languages have built-in functions for this (e.g., urllib.parse.quote in Python, encodeURIComponent in JavaScript).

  3. Inspect Request Headers and Body: Use a tool like Postman or your browser’s developer tools (Network tab) to inspect the exact request being sent to the /v1/oauth/token endpoint. Pay close attention to the following:

    • HTTP Method: Ensure you’re using a POST request.
    • Headers: Verify the Content-Type header is set to application/x-www-form-urlencoded.
    • Body: Double-check that the grant_type, code, redirect_uri, client_id, and client_secret parameters are correctly formatted and sent in the request body. The grant_type must be exactly "authorization_code".

  4. Handle Authorization Code Expiration: Implement logic in your application to handle potential authorization code expiration. Consider using shorter debugging cycles or refreshing the authorization code if necessary.

:mag: Common Pitfalls & What to Check Next:

  • Case Sensitivity: Miro’s API might be case-sensitive for certain parameters (like grant_type and redirect_uri).
  • Client Credentials: Double-check your client_id and client_secret for any typos.
  • API Rate Limits: Miro may have API rate limits. If you exceed these limits, you might receive a 401 error. Check Miro’s API documentation for rate limit information.
  • Testing Tools: Use a tool like Postman to test your requests in isolation and identify specific errors more easily.

:speech_balloon: Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!

6

Scope mismatch is probably what’s killing you. I kept getting 401s during token exchange because my auth scopes didn’t match what I was claiming in the token request. Miro’s OAuth is super picky about this - request board permissions during auth but mess up the token exchange? Silent 401 failure. Also caught me using the wrong HTTP method and throwing in random extra parameters that weren’t in the original auth flow. Strip your token request down to bare essentials and double-check your scopes match between both steps.

7

OAuth debugging sucks - too many moving pieces that fail silently.

I hit this exact issue building an integration pipeline. Wasted days tracking down 401s across different APIs, including Miro.

The problem? Manual OAuth means checking dozens of variables every single time. Auth codes, headers, encoding, timing, scopes, endpoints. Miss one detail and you’re stuck with cryptic 401s.

Game changer for me was automating the whole OAuth flow instead of hand-coding it. Now I build these flows visually and can see each step, test them separately.

Latenode handles OAuth automatically - token exchange, proper encoding, timeouts, secure token storage. No more guessing what broke.

You debug each step visually and see exactly where it fails instead of staring at 401 errors.

8

This topic was automatically closed 24 hours after the last reply. New replies are no longer allowed.