> For the complete documentation index, see [llms.txt](https://docs.imerit.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imerit.net/labeling/labeling-tools/relation/single-relation.md).
# Single Relation
Overview of the Single Relation tool in Ango Hub
The Single Relation labeling tool allows you to create a relation between two annotations.
{% hint style="info" %}
The Single Relation tool is supported across the Audio, Image, Video, DICOM, PDF, and Text labeling editors.
{% endhint %}
{% hint style="info" %}
Single relations are not visible unless the user is hovering over them with the mouse cursor.
{% endhint %}
## How to add a Single Relation tool to your project
From the project’s *Settings* tab, enter the *Label Set* section.
Click on *Add Category*. From the list that appears, click on *Single Relation*.
A new row will appear named *Single Relation*. Click on it to expand it.
Give your single relation tool a title and description.
Enable the *Required* toggle if you want to force labelers to create a single relation for each asset. When the toggle is disabled, labelers will be able to save and move to the next asset without creating the single relation.
### How to Draw a Single Relation
Click on the label where you’d like the single relation to start. Click on the second label where you’d like the relation to end. Press N on your keyboard to finalize the relation.
After having created the relation, you can change its direction by clicking on the small arrow inside the relation's box.
#### Single Relation Directions
* **Forward:** the first label points at the second label.
* **Backward:** the second label points at the second label.
* **Bidirectional:** The labels point at each other.
---
# Agent Instructions
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## Querying This Documentation
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```
GET https://docs.imerit.net/labeling/labeling-tools/relation/single-relation.md?ask=&goal=
```
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small arrow inside the relation's box.
#### Single Relation Directions
* **Forward:** the first label points at the second label.
* **Backward:** the second label points at the second label.
* **Bidirectional:** The labels point at each other.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://docs.imerit.net/labeling/labeling-tools/relation/single-relation.md?ask=