---
title: "Add Comment Reaction"
method: POST
path: "/api/v1/comments/{comment_id}/reactions"
tags: ["Comments"]
---

# Add Comment Reaction

`POST /api/v1/comments/{comment_id}/reactions`

## Request

- Base URL: `https://api.todoist.com`
- URL: `https://api.todoist.com/api/v1/comments/{comment_id}/reactions`
- Auth: none declared

Adds the authenticated user's reaction to a task or project comment and returns the updated comment.

Adding a reaction the user has already added leaves the reactions unchanged.
Returns an error if the comment's stored reactions would exceed 65,535 bytes.

## Path parameters

- `comment_id` string, required: String ID of the comment

## Request body

- Body579e1668
  - `reaction` string, required: Reaction emoji.

## Response `200`

Successful Response

- NoteSyncView: The base class for NoteSyncViews, to be extended for Items and Projects. This class should generally not be instantiated directly, as it serves as a common structure for Items and Projects.
  - `id` string, required: String ID of the comment.
  - `posted_uid` string, nullable, required: String ID of the user who posted the comment.
  - `content` string: Comment content.
  - `file_attachment` object, nullable, required: File attachment metadata, or `null` when the comment has no attachment.
  - `uids_to_notify` string[], nullable, required: String IDs of users notified by the comment.
  - `is_deleted` boolean, required: Whether the comment is deleted.
  - `posted_at` string, date-time, nullable, required: Date and time when the comment was posted, or `null` if unknown.
  - `reactions` object, nullable, required: Reaction emoji mapped to user IDs that reacted.

## Other responses

- `400`: Bad Request
- `401`: Unauthorized
- `403`: Forbidden
- `404`: Not Found

## Changes

- **2026-09-12** `69649d2d755a`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/todoist/apis/todoist-api/changes/api/v1/comments/:comment_id/reactions/post.md)

---

[API](https://skmtc.dev/todoist/apis/todoist-api.md) - [All operations](https://skmtc.dev/todoist/apis/todoist-api/llms.txt) - [OpenAPI document](https://skmtc.dev/todoist/apis/todoist-api/revisions/3c8cae93e5cc?raw)