# Zoom RTMS SDK - Closed caption support

**URL:** <https://devforum.zoom.us/t/zoom-rtms-sdk-closed-caption-support/137536>\
**Category:** Realtime Media Streams\
**Created:** [September 21, 2025, 7:37pm UTC](https://devforum.zoom.us/t/zoom-rtms-sdk-closed-caption-support/137536 "2025-09-21T19:37:24Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Jani](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/jani/32/52271_2.png) [@Jani](https://devforum.zoom.us/u/Jani)\
**Post date:** [September 21, 2025, 7:37pm UTC](https://devforum.zoom.us/t/zoom-rtms-sdk-closed-caption-support/137536/1 "2025-09-21T19:37:24Z")

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Is it possible to send closed captions to a Zoom meeting with the use of RTMS SDK? If possible, is there also a way to use custom websocket connection with right handshake followed by message?

Thanx

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**Author:** ![chunsiong.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/chunsiong.zoom/32/35488_2.png) [@chunsiong.zoom](https://devforum.zoom.us/u/chunsiong.zoom)\
**Post date:** [September 22, 2025, 2:47am UTC](https://devforum.zoom.us/t/zoom-rtms-sdk-closed-caption-support/137536/2 "2025-09-22T02:47:55Z")

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@Jani  
Currently the RTMS only supports output of media from a meeeting. Sending of media via RTMS into a meeting is not supported at the moment.

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**Author:** ![michael.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/michael.zoom/32/37213_2.png) [@michael.zoom](https://devforum.zoom.us/u/michael.zoom)\
**Post date:** [September 22, 2025, 4:51pm UTC](https://devforum.zoom.us/t/zoom-rtms-sdk-closed-caption-support/137536/3 "2025-09-22T16:51:47Z")

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@Jani we’d love to hear more about your use case as we think about bi-directional data possibilities 🙂

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<div class="post-metadata">

**Author:** ![Jani](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/jani/32/52271_2.png) [@Jani](https://devforum.zoom.us/u/Jani)\
**Post date:** [September 22, 2025, 8:56pm UTC](https://devforum.zoom.us/t/zoom-rtms-sdk-closed-caption-support/137536/4 "2025-09-22T20:56:09Z")

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Hi Michael,

We are planning to integrate near real-time transcriptions from our custom speech-to-text engine into Zoom meetings as closed captions.  
Since our engine supports simultaneous transcriptions in multiple languages, we may be sending a quite high volume of caption data into the meeting.

For real-time scenarios, closed captions are an ideal way to present the information because they don’t require a separate UI for participants.

Best regards,  
Jani