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ankur745's avatar
ankur745
Copper Contributor
Oct 03, 2023

Geeting CORS in API while calling inside Teams APP TAB

Getting CORS in API while calling inside Teams APP TAB Calling API in Teams App TAB

const u = `${domain}/api/login.json`;

  fetch(u, requestOptions)
    .then(resp => {
  }

While calling API we are getting CORS

 

 

Despite receiving correct responses in the network tab, the app is receiving different responses, possibly due to the restricted Teams SDK..

 

 

 

 

developer
microsoft teams
  • skander's avatar
    skander
    Copper Contributor
    Mar 03, 2025

    Trying to do the same thing, make a 3rd Party API calls from teams tab but getting CORS error, that mean that the call need to be done from a backend, it is not possible in my case. After researching potential solutions, there is azure relay, and it is not free.

     

    • ankur745's avatar
      ankur745
      Copper Contributor
      Oct 05, 2023
      Hey basically I want to call 3rd party API.. so how i can simply call API?
      • Prasad_Das-MSFT's avatar
        Prasad_Das-MSFT
        Icon for Microsoft rankMicrosoft
        Oct 11, 2023

        ankur745 - 

        Teams Platform/SDK doesn't do anything to interfere with AJAX requests made by apps. CORS is standard mechanism implemented by all browsers that limits cross-origin network calls. If an app is trying to make a cross-origin network request, then the backend API must allow it first by responding correctly to the OPTIONS call. Here is an example:

         

         

        There is documentation on CORS here:

        https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS

         

        Could you please provide us Fiddler trace of the request, so that we will be able to point out what the exact issue is?

    • ankur745's avatar
      ankur745
      Copper Contributor
      Oct 04, 2023

      Prasad_Das-MSFT No, it's not helpful. I'm receiving data from my server API but Teams SDK not passed that data to me... in code getting type = CORS issue..looks like Teams SDK restricting data . I have attached two screenshots to my question.

      Is the team's app tab allowing to call 3rd Party API?

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