Enable Graph Communications Calling API for Azure Bot App Registration

Hi Kai Sölter

Thank you for reaching out to Microsoft Q&A

As I am forum moderator, I don't have access to your Azure tenant, and I cannot provision or approve APIs for your App ID (which was also omitted from your message).

However, I can help you troubleshoot the 9999 Internal Server Error you are receiving when calling POST /beta/communications/calls. As far as I know, this specific error typically indicates that your app is not fully registered or configured in the Azure Bot Service with the Microsoft Teams channel.

To resolve this and enable the Graph Communications Calling API, please ensure the following steps are completed by your tenant administrator:

1. Azure App Registration Permissions

Ensure your Azure AD App Registration has the correct Application permissions for the APIs you intend to call, and that Admin Consent has been granted:

• Calls.Initiate.All
• Calls.InitiateGroupCall.All
• Calls.JoinGroupCall.All
• Calls.JoinGroupCallAsGuest.All (if joining as bot dynamically)

2. Azure Bot Registration & Calling Webhook (Critical for "9999" error)

To join meetings as a Bot or use calling APIs, you cannot simply call the endpoints using an Azure AD App Registration token. The app must be registered as a Bot Framework bot and linked to the Microsoft Teams channel.

Go to the Azure Portal.

Create an Azure Bot resource and link it to your existing App ID.

In the Azure Bot settings, go to Channels and add the Microsoft Teams channel.

On the Microsoft Teams channel settings page, open the Calling tab.

Enable Calling and provide a valid HTTPS Webhook for calling (ngrok or your live https endpoint).

Note: If the bot isn't connected to the Teams channel with the Calling webhook URL provided, calling the POST /communications/calls endpoints will throw the 9999 Internal Server Error.

Hope my answer will help you and kindly let me know in the comment section

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You’re seeing this error because the Microsoft Graph Communications Calling API (Cloud Communications API) is a protected, restricted API that requires special provisioning by Microsoft. Granting permissions in Azure AD alone is not enough.

Why you get error 7504 (“Insufficient enterprise tenant permissions”):

• The Calling API is not enabled by default for all tenants.
• You must request access from Microsoft to use these APIs, even in beta.
• The error means your tenant is not provisioned for the Cloud Communications API.

How to resolve

Request API Access from Microsoft:

Go to the Microsoft Graph Communications API Access Request Form.

Fill out the form with your tenant and app details, describing your use case (e.g., bot joining Teams meetings, transcription).

Wait for Microsoft to review and approve your request. This can take several days to weeks.

After Approval:

You’ll receive confirmation from Microsoft.

Re-consent the required permissions in Azure AD for your app (e.g., Calls.AccessMedia.All, Calls.JoinGroupCall.All, etc.).

Retry your API calls.

Check Required Licenses:

The app owner’s license (Business Premium) is not enough; the tenant must have Teams and the right licenses for calling features.