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

# Add Comment Reaction

> Add or update a reaction on a comment

Adds a reaction of the specified type to a comment. If the user already has a reaction on this comment, it is replaced with the new type. The comment's `reactionCounts` map is updated accordingly.

**Authentication required.**

## Path Parameters

<ParamField path="commentId" type="string" required>
  The UUID of the comment to react to.
</ParamField>

## Body Parameters

<ParamField body="reactionType" type="string" required>
  The type of reaction to add. One of: `upvote`, `downvote`, `like`, `love`, `wow`, `sad`, `angry`, `funny`.
</ParamField>

<ParamField body="userId" type="string">
  Override which user the reaction is attributed to. **Service or master key only.**
</ParamField>

## Response

Returns the updated [Comment](/data-models/comment) object with the new `reactionCounts` map.

## Error Responses

<AccordionGroup>
  <Accordion title="Not Found — 404">
    ```json theme={null}
    { "error": "Comment not found.", "code": "comment/not-found" }
    ```
  </Accordion>
</AccordionGroup>