Slack

Slack Reactions API

The Reactions API from Slack — 4 operation(s) for reactions.

Documentation GitHub OpenAPI

Operations 4

Each operation below carries the questions people ask an LLM about it and the instructions they give an agent to run it. Generated by API Evangelist overlay

POST /reactions.add Add an emoji reaction to a message · Slack Add an Emoji Reaction #

Ask an LLM

“How do I react to a message with an emoji through the API?”

“What scope does my app need to add reactions?”

Tell an agent

React with :{name}: to the message at {timestamp} in {channel}.

Add a {name} reaction to message {timestamp} in channel {channel}.

POST /reactions.remove Remove an emoji reaction · Slack Remove an Emoji Reaction #

Ask an LLM

“Can I take back a reaction I added by mistake?”

“Is it possible to remove a reaction from a file rather than a message?”

Tell an agent

Remove my :{name}: reaction from message {timestamp} in {channel}.

Remove the {name} reaction from file {file}.

GET /reactions.get Get the reactions on one item · Slack Get Reactions for an Item #

Ask an LLM

“Which emoji reactions has a specific message received?”

“Can I get the complete reaction list for a file, not just a summary?”

Tell an agent

Get the reactions on the message at {timestamp} in {channel}.

Show every reaction on file {file}, full list {full}.

GET /reactions.list List reactions a user has made · Slack List Reactions Made by a User #

Ask an LLM

“What has a given user reacted to lately?”

“How do I page through all the reactions I've added?”

Tell an agent

List the reactions made by user {user}.

Show my {limit} most recent reactions.

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OpenAPI Specification

openapi: 3.2.0
info:
  title: Slack Web Reactions API
  description: The Slack Web API is an HTTP-based interface that provides access to all of Slack's platform features.
  version: 1.0.0
  termsOfService: https://slack.com/terms-of-service/api
  contact:
    name: Slack Developer Support
    url: https://docs.slack.dev
  license:
    name: Slack API Terms of Service
    url: https://slack.com/terms-of-service/api
servers:
- url: https://slack.com/api
  description: Slack Web API production server
security:
- bearerAuth: []
tags:
- name: Reactions
  description: Add and manage emoji reactions
paths:
  /reactions.add:
    post:
      tags:
      - Reactions
      summary: Slack Add an Emoji Reaction
      description: Adds a reaction (emoji) to a message, file, or file comment. Requires reactions:write scope.
      operationId: reactionsAdd
      externalDocs:
        description: API method documentation
        url: https://docs.slack.dev/reference/methods/reactions.add
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - channel
              - name
              - timestamp
              properties:
                channel:
                  type: string
                  description: Channel where the message to add reaction to was posted.
                name:
                  type: string
                  description: Reaction (emoji) name without colons.
                timestamp:
                  type: string
                  description: Timestamp of the message to add reaction to.
      responses:
        '200':
          description: Reaction added
          content:
            application/json:
              schema:
                type: object
                properties:
                  ok:
                    type: boolean
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /reactions.remove:
    post:
      tags:
      - Reactions
      summary: Slack Remove an Emoji Reaction
      description: Removes a reaction (emoji) from an item.
      operationId: reactionsRemove
      externalDocs:
        description: API method documentation
        url: https://docs.slack.dev/reference/methods/reactions.remove
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - name
              properties:
                channel:
                  type: string
                name:
                  type: string
                  description: Reaction (emoji) name without colons.
                timestamp:
                  type: string
                file:
                  type: string
                file_comment:
                  type: string
      responses:
        '200':
          description: Reaction removed
          content:
            application/json:
              schema:
                type: object
                properties:
                  ok:
                    type: boolean
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /reactions.get:
    get:
      tags:
      - Reactions
      summary: Slack Get Reactions for an Item
      description: Gets reactions for an item (message, file, or file comment).
      operationId: reactionsGet
      externalDocs:
        description: API method documentation
        url: https://docs.slack.dev/reference/methods/reactions.get
      parameters:
      - name: channel
        in: query
        description: Channel where the message to get reactions for was posted.
        schema:
          type: string
      - name: file
        in: query
        description: File to get reactions for.
        schema:
          type: string
      - name: file_comment
        in: query
        description: File comment to get reactions for.
        schema:
          type: string
      - name: full
        in: query
        description: If true, return complete reaction list.
        schema:
          type: boolean
      - name: timestamp
        in: query
        description: Timestamp of the message to get reactions for.
        schema:
          type: string
      responses:
        '200':
          description: Reactions retrieved
          content:
            application/json:
              schema:
                type: object
                properties:
                  ok:
                    type: boolean
                  type:
                    type: string
                  message:
                    $ref: '#/components/schemas/Message'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /reactions.list:
    get:
      tags:
      - Reactions
      summary: Slack List Reactions Made by a User
      description: Lists reactions made by a user. Paginated with cursor-based pagination.
      operationId: reactionsList
      externalDocs:
        description: API method documentation
        url: https://docs.slack.dev/reference/methods/reactions.list
      parameters:
      - name: count
        in: query
        schema:
          type: integer
          default: 100
      - name: cursor
        in: query
        schema:
          type: string
      - name: full
        in: query
        schema:
          type: boolean
      - name: limit
        in: query
        schema:
          type: integer
          default: 100
      - name: page
        in: query
        schema:
          type: integer
          default: 1
      - name: user
        in: query
        description: Show reactions made by this user.
        schema:
          type: string
      responses:
        '200':
          description: Reactions listed
          content:
            application/json:
              schema:
                type: object
                properties:
                  ok:
                    type: boolean
                  items:
                    type: array
                    items:
                      type: object
                  response_metadata:
                    $ref: '#/components/schemas/ResponseMetadata'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
components:
  schemas:
    ResponseMetadata:
      type: object
      description: Metadata for paginated responses containing cursor information.
      properties:
        next_cursor:
          type: string
          description: An opaque cursor to use in the next request to get the next page of results. Empty string indicates no more results.
          example: example_value
    File:
      type: object
      description: A Slack file object representing an uploaded file with its metadata and sharing information.
      properties:
        id:
          type: string
          description: Unique file identifier.
          example: abc123
        created:
          type: integer
          description: Unix timestamp of when the file was created.
          example: 10
        timestamp:
          type: integer
          description: Unix timestamp.
          example: 10
        name:
          type: string
          description: The file name.
          example: Example Title
        title:
          type: string
          description: Title of the file.
          example: Example Title
        mimetype:
          type: string
          description: MIME type of the file.
          example: example_value
        filetype:
          type: string
          description: Slack file type identifier (e.g., "png", "pdf", "snippet").
          example: example_value
        pretty_type:
          type: string
          description: Human-readable file type.
          example: example_value
        user:
          type: string
          description: User ID of the user who uploaded the file.
          example: example_value
        user_team:
          type: string
          description: Team ID of the user who uploaded the file.
          example: example_value
        editable:
          type: boolean
          description: Whether the file content is editable.
          example: true
        size:
          type: integer
          description: File size in bytes.
          example: 10
        mode:
          type: string
          description: File mode (e.g., "hosted", "external", "snippet", "post").
          example: example_value
        is_external:
          type: boolean
          description: Whether the file is externally hosted.
          example: true
        external_type:
          type: string
          description: Type of external file.
          example: example_value
        is_public:
          type: boolean
          description: Whether the file is public.
          example: true
        public_url_shared:
          type: boolean
          example: https://www.example.com
        display_as_bot:
          type: boolean
          example: true
        username:
          type: string
          example: example_value
        url_private:
          type: string
          format: uri
          description: URL to access the file. Requires authentication.
          example: https://www.example.com
        url_private_download:
          type: string
          format: uri
          description: URL to download the file. Requires authentication.
          example: https://www.example.com
        permalink:
          type: string
          format: uri
          description: Permalink URL for the file.
          example: https://www.example.com
        permalink_public:
          type: string
          format: uri
          description: Public permalink URL for the file (if shared publicly).
          example: https://www.example.com
        channels:
          type: array
          description: Array of channel IDs where the file is shared.
          items:
            type: string
          example: []
        groups:
          type: array
          description: Array of private channel IDs where the file is shared.
          items:
            type: string
          example: []
        ims:
          type: array
          description: Array of DM IDs where the file is shared.
          items:
            type: string
          example: []
        shares:
          type: object
          description: Sharing information broken down by type.
          example: example_value
        comments_count:
          type: integer
          description: Number of comments on the file.
          example: 10
    Message:
      type: object
      description: A Slack message object representing a single message in a conversation. Messages can contain text, blocks, attachments, files, and reactions.
      properties:
        type:
          type: string
          description: Always "message" for messages.
          const: message
          example: example_value
        subtype:
          type: string
          description: Optional subtype indicating a specialized message type such as bot_message, channel_join, channel_leave, etc.
          example: example_value
        channel:
          type: string
          description: The channel ID where the message was posted.
          example: example_value
        user:
          type: string
          description: The user ID of the message author.
          example: example_value
        text:
          type: string
          description: The text content of the message.
          example: example_value
        ts:
          type: string
          description: Unique timestamp identifier for the message, also serves as the message ID. Format is Unix epoch with microseconds (e.g., "1503435956.000247").
          example: example_value
        thread_ts:
          type: string
          description: The timestamp of the parent message in a thread. Present only for threaded replies.
          example: example_value
        reply_count:
          type: integer
          description: Number of replies in the thread.
          example: 10
        reply_users_count:
          type: integer
          description: Number of unique users who have replied in the thread.
          example: 10
        latest_reply:
          type: string
          description: Timestamp of the most recent reply in the thread.
          example: example_value
        reply_users:
          type: array
          description: Array of user IDs who have replied in the thread.
          items:
            type: string
          example: []
        blocks:
          type: array
          description: An array of Block Kit layout blocks used for rich message formatting.
          items:
            type: object
          example: []
        attachments:
          type: array
          description: An array of message attachments.
          items:
            type: object
            properties:
              id:
                type: integer
              color:
                type: string
              fallback:
                type: string
              text:
                type: string
              pretext:
                type: string
              author_name:
                type: string
              author_link:
                type: string
                format: uri
              author_icon:
                type: string
                format: uri
              title:
                type: string
              title_link:
                type: string
                format: uri
              fields:
                type: array
                items:
                  type: object
                  properties:
                    title:
                      type: string
                    value:
                      type: string
                    short:
                      type: boolean
              footer:
                type: string
              footer_icon:
                type: string
                format: uri
              ts:
                type: integer
          example: []
        files:
          type: array
          description: An array of file objects attached to the message.
          items:
            $ref: '#/components/schemas/File'
          example: []
        reactions:
          type: array
          description: An array of emoji reactions on this message.
          items:
            type: object
            properties:
              name:
                type: string
                description: Emoji name without colons.
              count:
                type: integer
                description: Number of users who added this reaction.
              users:
                type: array
                description: User IDs of users who added this reaction.
                items:
                  type: string
          example: []
        edited:
          type: object
          description: Edit information if the message was edited.
          properties:
            user:
              type: string
            ts:
              type: string
          example: example_value
        bot_id:
          type: string
          description: Bot ID if the message was posted by a bot.
          example: '500123'
        bot_profile:
          type: object
          description: Bot profile information if posted by a bot.
          properties:
            id:
              type: string
            deleted:
              type: boolean
            name:
              type: string
            updated:
              type: integer
            app_id:
              type: string
            icons:
              type: object
          example: example_value
        metadata:
          type: object
          description: Custom metadata attached to the message by an application.
          properties:
            event_type:
              type: string
            event_payload:
              type: object
          example: example_value
        permalink:
          type: string
          format: uri
          description: Permalink URL for the message.
          example: https://www.example.com
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Slack API uses Bearer token authentication. Pass a bot token or user token in the Authorization header.

Slack Reactions API

Operations 4

Documentation

Specifications

Schemas & Data

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OpenAPI Specification