---
updatedAt: 2025-11-11T01:51:16.000Z
agentTools:
  projectIndex: https://docs.formant.io/llms.txt
---

# Cannot add multiple topics to a stream

# Issue details

* I am trying to add multiple fields of my ROS topics to one stream, but I cannot. I even try adding tags and can’t get the data to show and the tags don’t persist.

# Troubleshooting steps

When adding multiple ROS topics to the same data stream, they must be of the same data type, and you must add a unique set of tags to each topic.

When adding tags, be sure to hit the **Enter** key to apply tags to that stream. When correctly added, the tag will look like this:

<Image align="center" src="https://files.readme.io/fc31f0a-Screenshot_2024-03-19_at_5.14.28_PM.png" />

# See also

* [Add a ROS topic stream](https://docs.formant.io/docs/getting-started-add-a-ros-topic-stream)
* [How telemetry streams work](https://docs.formant.io/docs/how-telemetry-streams-work)
* [Configure access levels](https://docs.formant.io/docs/getting-started-configure-access-levels)

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