> ## Documentation Index
> Fetch the complete documentation index at: https://langwatch.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> Learn how annotations enhance trace review, labeling, and evaluation workflows for more reliable AI agent testing.

## Intro

With the Annotations API, you can annotate traces with additional information. This is useful if you want to add additional information to a trace, such as a comment or a thumbs up/down reaction.

## Authentication

To make a call to the Annotations API, you will need to pass through your LangWatch API key in the header as `X-Auth-Token`. Your API key can be found on the setup page under settings.

#### Allowed Methods

* `GET /api/annotations` - Get a list of annotations
* `GET /api/annotations/:id` - Get a single annotation
* `DELETE /api/annotations/:id` - Delete a single annotation
* `PATCH /api/annotations/:id` - Update a single annotation
* `GET /api/annotations/trace/:id` - Get the annotations for a single trace
* `POST /api/annotations/trace/:id` - Create annotations for traces to support domain labeling, evaluation scoring, and agent testing workflows.