I have a problem with a logic app calling an azure function app. Its failing with an Unauthorized error

Question

I have an azure logic app "logic-nats-test-func". It calls an azure function app called "func-assurityimport-nats-dev". It is displaying "Unauthorized" when it is run.

When it is run I can see the function running by looking in the Log Stream, but it always returns this :

{ "statusCode": 401, "headers": { "Date": "Mon, 17 Feb 2025 15:55:50 GMT", "WWW-Authenticate": "Bearer", "Request-Context": "appId=cid-v1:58850597-4e54-4d55-9584-88976280b385", "Content-Length": "0" } }

I don't have any bearer token authentication enabled. I also have a test function with the same app and that works fine. Both functions are using the same function signature :

        public async Task<HttpResponseData> HttpStartNATS(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post")] HttpRequestData req)

Answer 1

Chris Crowhurst

It seems like you're encountering an "Unauthorized" error when running your Azure Logic App "logic-nats-test-func" which calls the Azure Function App "func-assurityimport-nats-dev". The error message indicates a missing valid access token.

You've mentioned that adding the x-functions-key to the header didn't resolve the issue. Could you please confirm if you have tried invoking the function through Postman or curl with the function key? This will help determine if the issue is specific to the Logic App or if it persists across different methods of invocation.

Your feedback on this matter would be greatly appreciated. Please let me know if this approach works or if you require further assistance.

Answer 2

[Duplicate]

Answer 3

Hi @Chris Crowhurst

As an Alternative you try below approach if you are still facing this issue:

In place of Azure functions connector, you can simply use a Http calling connector which works same as postman and Azure functions connector also.

Here, I had used POST method, in which I have got first part of url from http trigger and second part from Aure function keys as below:

https://funcappname.azurewebsites.net/api/funcname?

Then code=key :

Output:

Hope this helps.

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