> ## 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.

# Toggle Message Reaction

> Add or remove an emoji reaction on a chat message

Toggles an emoji reaction on a message. If the current user has not yet reacted with this emoji, the reaction is added. If they already have, it is removed. The caller must be an active member.

The `emoji` must be exactly one grapheme cluster (a single visible character, including multi-codepoint emoji like `👨‍👩‍👧`).

## Path Parameters

<ParamField path="conversationId" type="string" required>
  The ID of the conversation.
</ParamField>

<ParamField path="messageId" type="string" required>
  The ID of the message to react to.
</ParamField>

## Body Parameters

<ParamField body="emoji" type="string" required>
  The emoji to toggle. Must be exactly one grapheme cluster.
</ParamField>

## Response

<ResponseField name="reactionCounts" type="Record<string, number>">
  Updated emoji reaction counts for this message (e.g. `{ "👍": 3, "❤️": 1 }`).
</ResponseField>

<ResponseField name="userReactions" type="string[]">
  The current user's full set of reactions on this message after the toggle.
</ResponseField>

<ResponseField name="delta" type="number">
  `1` if a reaction was added, `-1` if removed.
</ResponseField>

## Error Responses

<AccordionGroup>
  <Accordion title="Invalid Emoji — 400 Bad Request">
    ```json theme={null}
    { "error": "Emoji must be exactly one grapheme cluster.", "code": "chat/invalid-emoji" }
    ```
  </Accordion>

  <Accordion title="Forbidden — 403">
    ```json theme={null}
    { "error": "You are not a member of this conversation.", "code": "chat/not-a-member" }
    ```
  </Accordion>

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