Cannot authenticate to Azure Video Indexer API (AADSTS700016 – app not found in tenant)

Hello @Josheph

Welcome to Microsoft Q&A .Thank you for reaching out to us.

This behavior aligns with scenarios where authentication is attempted using an unsupported application identity. Once the request is aligned with the supported Video Indexer authentication flow, the service should function as expected without additional Azure AD configuration changes.

The error indicates that the application identity used during authentication cannot be found in the tenant. According to Entra ID error guidance, this typically occurs when an application is not recognized in the directory, is incorrectly configured, or the authentication request is sent using an unsupported context.

Azure Video Indexer APIs are not enabled or registered manually through Azure AD. Access is managed through the Video Indexer account and its associated authentication mechanisms.

The usage begins by creating a Video Indexer account and subscribing to the API, after which authentication is performed using account-level keys or tokens, rather than registering APIs in Azure AD.

The supported Authentication methods are-

1. API Key Authentication
   1. Uses Video Indexer account subscription keys
   2. No Azure AD configuration required
   3. Simplest and most reliable method for most scenarios
2. Token-Based Authentication (ARM Accounts)
   1. Uses an access token generated for the Video Indexer account
   2. Token is scoped to the account and used for API calls
   Access token can be generated using the ARM API:
   • Method: POST request
   • Endpoint (structure) https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.VideoIndexer/accounts/{accountName}/generateAccessToken

This API returns an access token tied to the account, which can then be used for subsequent operations.

To resolve the issue, the following steps are recommended:

1. Consider removing the unsupported application ID usage -Avoid using hardcoded or undocumented App IDs in authentication requests
2. Select a supported authentication method - Prefer API Key authentication for simplicity.Alternatively, use token-based authentication tied to the Video Indexer account
3. Use account-based token generation (for ARM accounts) - Generating an access token using the Video Indexer resource.Use the returned token for API calls.
4. Validating tenant endpoint usage - Ensure authentication requests are directed to the correct tenant: https://login.microsoftonline.com/{tenant-id}
5. Validating account readiness - Please sign in to the Video Indexer portal and perform a test action such as uploading media to ensure initialization

The following references might be helpful , please check them out

• Use the Azure AI Video Indexer API | Microsoft Learn
• Generate - Access Token - REST API (Azure Azure Video Indexer) | Microsoft Learn

Thank you