Understanding Zoom RTMS and Third-Party App Permissions in External Meetings

As a developer building innovative experiences using Zoom’s Realtime Media Streams (RTMS), a question that might arise around app behavior—especially apps are involved in meetings hosted outside your organization might be:

How does Zoom manage Realtime Media Streams when a guest user—running an RTMS-enabled app—joins a meeting hosted by someone else?

When a user joins an external Zoom meeting with an RTMS app—whether it’s a privately deployed app or one published on the Zoom Marketplace—the app doesn’t automatically begin streaming. Instead:

  • The host of the meeting receives an in-meeting prompt to approve or deny the app’s request to start the RTMS session.
  • The ability for that prompt to even appear may depend on the host organization’s admin settings, which can enable or restrict third-party app usage altogether.

This means the experience can vary significantly:

  • In some meetings, the stream might start immediately after host approval.
  • In others, the app may be blocked entirely based on organizational policy.
  • For apps published on the Zoom Marketplace, hosts and admins can pre-authorize usage via app permissions and scopes—streamlining the guest experience while maintaining control.