Slack

Slack Add API

The Add API from Slack — 9 operation(s) for add.

Documentation GitHub OpenAPI

Operations 6

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 /admin.emoji.add Add a custom emoji to the workspace · Slack Post Admin Emoji Add #

Ask an LLM

“How do I upload a custom emoji to our Slack workspace as an admin?”

“What does a new emoji need, a name and an image URL?”

Tell an agent

Add custom emoji {name} using the image at {url}.

Create the :{name}: emoji from {url}.

POST /calls.add Register a new call · Slack Post Calls Add #

Ask an LLM

“Can my video app register a call so it shows up in a channel?”

“What join URL and ID do I need to register a call?”

Tell an agent

Register call {external_unique_id} with join link {join_url}.

Register a call titled {title} starting at {date_start} joinable at {join_url} with ID {external_unique_id}.

POST /calls.participants.add Add participants to a registered call · Slack Post Calls Participants Add #

Ask an LLM

“How do I show that new people have joined a call my app registered?”

“Can I register several participants joining a call at once?”

Tell an agent

Add participants {users} to call {id}.

Record that {users} joined the registered call {id}.

POST /files.remote.add Add a file from a remote service · Slack Post Files Remote Add #

Ask an LLM

“Can I add a file that lives in my own service to Slack without uploading it?”

“Is it possible to make a remote file's contents searchable?”

Tell an agent

Add remote file {title} at {external_url} with external ID {external_id}.

Register the remote {filetype} file {external_id} with preview image {preview_image}.

POST /reminders.add Create a reminder · Slack Post Reminders Add #

Ask an LLM

“Can I set a reminder for myself or a teammate?”

“What time formats does creating a reminder accept?”

Tell an agent

Remind me to {text} at {time}.

Set a reminder for {user} to {text} at {time}.

POST /stars.add Star a message, file or channel · Slack Post Stars Add #

Ask an LLM

“How do I save a message for later by starring it?”

“Which things can be starred, a file, a channel or a message?”

Tell an agent

Star the message at {timestamp} in {channel}.

Add a star to file {file}.

Work with this as data

Every API here is available over the APIs.io API and to AI agents over MCP.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for apis

7 MCP tools reach this

find_apisBrowse and filter every API in the catalog.
get_api_artifactsOne API's artifacts, grouped by type.
get_openapiThe primary OpenAPI for this API.
find_similar_apisAPIs that look like this one.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
resolveTurn a domain, URL or GitHub org into the provider it belongs to.
find_cohortsEvery scored population of providers in the catalog.

All 92 tools →

Call it yourself

curl for this page

This API

curl "https://apis.io/api/v1/apis/slack:slack-add-api"

All apis

curl "https://apis.io/api/v1/apis?limit=25"

Calls without X-API-Key need no key. Calls with it need a paid plan — get a key.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

GitHub Google LinkedIn

A second provider on the same verified email joins the account you already have.

OpenAPI Specification

openapi: 3.2.0
info:
  title: Slack Add API
  version: '1.0'
  description: 'Operations tagged Add across 5 of this provider''s published API definitions: slack-admin-openapi.yml, slack-calls-openapi.yml, slack-files-openapi.yml, slack-reminders-openapi.yml, slack-stars-openapi.yml. Each path carries the servers of the definition it was published in.'
tags:
- name: Add
paths:
  /admin.emoji.add:
    post:
      tags:
      - Add
      description: Add an emoji.
      externalDocs:
        description: API method documentation
        url: https://api.slack.com/methods/admin.emoji.add
      operationId: postAdminEmojiAdd
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              required:
              - name
              - token
              - url
              type: object
              properties:
                token:
                  type: string
                  description: 'Authentication token. Requires scope: `admin.teams:write`'
                name:
                  type: string
                  description: The name of the emoji to be removed. Colons (`:myemoji:`) around the value are not required, although they may be included.
                url:
                  type: string
                  description: The URL of a file to use as an image for the emoji. Square images under 128KB and with transparent backgrounds work best.
        required: true
      responses:
        '200':
          description: Typical success response
          content:
            application/json:
              schema:
                title: Default success template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_true'
                additionalProperties: true
                description: This method either only returns a brief _OK_ response or a verbose schema is not available for this method.
              example:
                ok: true
        default:
          description: Typical error response
          content:
            application/json:
              schema:
                title: Default error template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_false'
                additionalProperties: true
                description: This method either only returns a brief _not OK_ response or a verbose schema is not available for this method.
              example:
                error: invalid_auth
                ok: false
      security:
      - slackAuth:
        - admin.teams:write
      summary: Slack Post Admin Emoji Add
      x-api-evangelist-processing:
        GenerateOperationSummariesFromPath: true
        PascalCaseOperationSummaries: true
        CaselCaseOperationIds: true
        ChooseTags: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /calls.add:
    post:
      tags:
      - Add
      description: Registers a new Call.
      externalDocs:
        description: API method documentation
        url: https://api.slack.com/methods/calls.add
      operationId: calls_add
      parameters:
      - name: token
        in: header
        description: 'Authentication token. Requires scope: `calls:write`'
        required: true
        schema:
          type: string
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              required:
              - external_unique_id
              - join_url
              type: object
              properties:
                external_unique_id:
                  type: string
                  description: An ID supplied by the 3rd-party Call provider. It must be unique across all Calls from that service.
                external_display_id:
                  type: string
                  description: An optional, human-readable ID supplied by the 3rd-party Call provider. If supplied, this ID will be displayed in the Call object.
                join_url:
                  type: string
                  description: The URL required for a client to join the Call.
                desktop_app_join_url:
                  type: string
                  description: When supplied, available Slack clients will attempt to directly launch the 3rd-party Call with this URL.
                date_start:
                  type: integer
                  description: Call start time in UTC UNIX timestamp format
                  format: int32
                title:
                  type: string
                  description: The name of the Call.
                created_by:
                  type: string
                  description: The valid Slack user ID of the user who created this Call. When this method is called with a user token, the `created_by` field is optional and defaults to the authed user of the token. Otherwise, the field is required.
                users:
                  type: string
                  description: The list of users to register as participants in the Call. [Read more on how to specify users here](/apis/calls#users).
          application/json:
            schema:
              required:
              - external_unique_id
              - join_url
              type: object
              properties:
                external_unique_id:
                  type: string
                  description: An ID supplied by the 3rd-party Call provider. It must be unique across all Calls from that service.
                external_display_id:
                  type: string
                  description: An optional, human-readable ID supplied by the 3rd-party Call provider. If supplied, this ID will be displayed in the Call object.
                join_url:
                  type: string
                  description: The URL required for a client to join the Call.
                desktop_app_join_url:
                  type: string
                  description: When supplied, available Slack clients will attempt to directly launch the 3rd-party Call with this URL.
                date_start:
                  type: integer
                  description: Call start time in UTC UNIX timestamp format
                  format: int32
                title:
                  type: string
                  description: The name of the Call.
                created_by:
                  type: string
                  description: The valid Slack user ID of the user who created this Call. When this method is called with a user token, the `created_by` field is optional and defaults to the authed user of the token. Otherwise, the field is required.
                users:
                  type: string
                  description: The list of users to register as participants in the Call. [Read more on how to specify users here](/apis/calls#users).
        required: true
      responses:
        '200':
          description: Typical success response
          content:
            application/json:
              schema:
                title: Default success template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_true'
                additionalProperties: true
                description: This method either only returns a brief _OK_ response or a verbose schema is not available for this method.
              example:
                ok: true
        default:
          description: Typical error response
          content:
            application/json:
              schema:
                title: Default error template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_false'
                additionalProperties: true
                description: This method either only returns a brief _not OK_ response or a verbose schema is not available for this method.
              example:
                error: invalid_auth
                ok: false
      security:
      - slackAuth:
        - calls:write
      summary: Slack Post Calls Add
      x-api-evangelist-processing:
        GenerateOperationSummariesFromPath: true
        PascalCaseOperationSummaries: true
        PascalCaseOperationTags: true
        ChooseTags: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /calls.participants.add:
    post:
      tags:
      - Add
      description: Registers new participants added to a Call.
      externalDocs:
        description: API method documentation
        url: https://api.slack.com/methods/calls.participants.add
      operationId: calls_participants_add
      parameters:
      - name: token
        in: header
        description: 'Authentication token. Requires scope: `calls:write`'
        required: true
        schema:
          type: string
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              required:
              - id
              - users
              type: object
              properties:
                id:
                  type: string
                  description: '`id` returned by the [`calls.add`](/methods/calls.add) method.'
                users:
                  type: string
                  description: The list of users to add as participants in the Call. [Read more on how to specify users here](/apis/calls#users).
          application/json:
            schema:
              required:
              - id
              - users
              type: object
              properties:
                id:
                  type: string
                  description: '`id` returned by the [`calls.add`](/methods/calls.add) method.'
                users:
                  type: string
                  description: The list of users to add as participants in the Call. [Read more on how to specify users here](/apis/calls#users).
        required: true
      responses:
        '200':
          description: Typical success response
          content:
            application/json:
              schema:
                title: Default success template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_true'
                additionalProperties: true
                description: This method either only returns a brief _OK_ response or a verbose schema is not available for this method.
              example:
                ok: true
        default:
          description: Typical error response
          content:
            application/json:
              schema:
                title: Default error template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_false'
                additionalProperties: true
                description: This method either only returns a brief _not OK_ response or a verbose schema is not available for this method.
              example:
                error: invalid_auth
                ok: false
      security:
      - slackAuth:
        - calls:write
      summary: Slack Post Calls Participants Add
      x-api-evangelist-processing:
        GenerateOperationSummariesFromPath: true
        PascalCaseOperationSummaries: true
        PascalCaseOperationTags: true
        ChooseTags: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /files.remote.add:
    post:
      tags:
      - Add
      description: Adds a file from a remote service
      externalDocs:
        description: API method documentation
        url: https://api.slack.com/methods/files.remote.add
      operationId: postFilesRemoteAdd
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:
                token:
                  type: string
                  description: 'Authentication token. Requires scope: `remote_files:write`'
                external_id:
                  type: string
                  description: Creator defined GUID for the file.
                title:
                  type: string
                  description: Title of the file being shared.
                filetype:
                  type: string
                  description: type of file
                external_url:
                  type: string
                  description: URL of the remote file.
                preview_image:
                  type: string
                  description: Preview of the document via `multipart/form-data`.
                indexable_file_contents:
                  type: string
                  description: A text file (txt, pdf, doc, etc.) containing textual search terms that are used to improve discovery of the remote file.
      responses:
        '200':
          description: Typical success response
          content:
            application/json:
              schema:
                title: Default success template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_true'
                additionalProperties: true
                description: This method either only returns a brief _OK_ response or a verbose schema is not available for this method.
              example:
                ok: true
        default:
          description: Typical error response
          content:
            application/json:
              schema:
                title: Default error template
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_false'
                additionalProperties: true
                description: This method either only returns a brief _not OK_ response or a verbose schema is not available for this method.
              example:
                error: invalid_auth
                ok: false
      security:
      - slackAuth:
        - remote_files:write
      summary: Slack Post Files Remote Add
      x-api-evangelist-processing:
        GenerateOperationSummariesFromPath: true
        PascalCaseOperationSummaries: true
        CaselCaseOperationIds: true
        ChooseTags: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /reminders.add:
    post:
      tags:
      - Add
      description: Creates a reminder.
      externalDocs:
        description: API method documentation
        url: https://api.slack.com/methods/reminders.add
      operationId: postRemindersAdd
      parameters:
      - name: token
        in: header
        description: 'Authentication token. Requires scope: `reminders:write`'
        required: true
        schema:
          type: string
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              required:
              - text
              - time
              type: object
              properties:
                text:
                  type: string
                  description: The content of the reminder
                time:
                  type: string
                  description: 'When this reminder should happen: the Unix timestamp (up to five years from now), the number of seconds until the reminder (if within 24 hours), or a natural language description (Ex. "in 15 minutes," or "every Thursday")'
                user:
                  type: string
                  description: The user who will receive the reminder. If no user is specified, the reminder will go to user who created it.
          application/json:
            schema:
              required:
              - text
              - time
              type: object
              properties:
                text:
                  type: string
                  description: The content of the reminder
                time:
                  type: string
                  description: 'When this reminder should happen: the Unix timestamp (up to five years from now), the number of seconds until the reminder (if within 24 hours), or a natural language description (Ex. "in 15 minutes," or "every Thursday")'
                user:
                  type: string
                  description: The user who will receive the reminder. If no user is specified, the reminder will go to user who created it.
        required: true
      responses:
        '200':
          description: Typical success response
          content:
            application/json:
              schema:
                title: reminders.add schema
                required:
                - ok
                - reminder
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_true'
                  reminder:
                    $ref: '#/components/schemas/objs_reminder'
                additionalProperties: false
                description: Schema for successful response from reminders.add method
              example:
                ok: true
        default:
          description: Typical error response
          content:
            application/json:
              schema:
                title: reminders.add error schema
                required:
                - error
                - ok
                type: object
                properties:
                  callstack:
                    type: string
                    description: 'Note: PHP callstack is only visible in dev/qa'
                  error:
                    type: string
                    enum:
                    - cannot_parse
                    - user_not_found
                    - cannot_add_bot
                    - cannot_add_slackbot
                    - cannot_add_others
                    - cannot_add_others_recurring
                    - not_authed
                    - invalid_auth
                    - account_inactive
                    - token_revoked
                    - no_permission
                    - org_login_required
                    - user_is_bot
                    - invalid_arg_name
                    - invalid_array_arg
                    - invalid_charset
                    - invalid_form_data
                    - invalid_post_type
                    - missing_post_type
                    - team_added_to_org
                    - invalid_json
                    - json_not_object
                    - request_timeout
                    - upgrade_required
                    - fatal_error
                  ok:
                    $ref: '#/components/schemas/defs_ok_false'
                additionalProperties: false
                description: Schema for error response from reminders.add method
              example:
                error: invalid_auth
                ok: false
      security:
      - slackAuth:
        - reminders:write
      summary: Slack Post Reminders Add
      x-api-evangelist-processing:
        GenerateOperationSummariesFromPath: true
        PascalCaseOperationSummaries: true
        CaselCaseOperationIds: true
        ChooseTags: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /stars.add:
    post:
      tags:
      - Add
      description: Adds a star to an item.
      externalDocs:
        description: API method documentation
        url: https://api.slack.com/methods/stars.add
      operationId: postStarsAdd
      parameters:
      - name: token
        in: header
        description: 'Authentication token. Requires scope: `stars:write`'
        required: true
        schema:
          type: string
      requestBody:
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              properties:
                channel:
                  type: string
                  description: Channel to add star to, or channel where the message to add star to was posted (used with `timestamp`).
                file:
                  type: string
                  description: File to add star to.
                file_comment:
                  type: string
                  description: File comment to add star to.
                timestamp:
                  type: string
                  description: Timestamp of the message to add star to.
          application/json:
            schema:
              type: object
              properties:
                channel:
                  type: string
                  description: Channel to add star to, or channel where the message to add star to was posted (used with `timestamp`).
                file:
                  type: string
                  description: File to add star to.
                file_comment:
                  type: string
                  description: File comment to add star to.
                timestamp:
                  type: string
                  description: Timestamp of the message to add star to.
      responses:
        '200':
          description: Typical success response
          content:
            application/json:
              schema:
                title: stars.add schema
                required:
                - ok
                type: object
                properties:
                  ok:
                    $ref: '#/components/schemas/defs_ok_true'
                additionalProperties: false
                description: Schema for successful response from stars.add method
              example:
                ok: true
        default:
          description: Typical error response
          content:
            application/json:
              schema:
                title: stars.add error schema
                required:
                - error
                - ok
                type: object
                properties:
                  callstack:
                    type: string
                    description: 'Note: PHP callstack is only visible in dev/qa'
                  error:
                    type: string
                    enum:
                    - bad_timestamp
                    - message_not_found
                    - file_not_found
                    - file_comment_not_found
                    - channel_not_found
                    - no_item_specified
                    - already_starred
                    - not_authed
                    - invalid_auth
                    - account_inactive
                    - token_revoked
                    - no_permission
                    - org_login_required
                    - invalid_arg_name
                    - invalid_array_arg
                    - invalid_charset
                    - invalid_form_data
                    - invalid_post_type
                    - missing_post_type
                    - team_added_to_org
                    - invalid_json
                    - json_not_object
                    - request_timeout
                    - upgrade_required
                    - fatal_error
                  ok:
                    $ref: '#/components/schemas/defs_ok_false'
                additionalProperties: false
                description: Schema for error response from stars.add method
              example:
                error: invalid_auth
                ok: false
      security:
      - slackAuth:
        - stars:write
      summary: Slack Post Stars Add
      x-api-evangelist-processing:
        GenerateOperationSummariesFromPath: true
        PascalCaseOperationSummaries: true
        CaselCaseOperationIds: true
        ChooseTags: true
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
x-refined-from:
- slack-admin-openapi.yml
- slack-calls-openapi.yml
- slack-files-openapi.yml
- slack-reminders-openapi.yml
- slack-stars-openapi.yml

Slack Add API

Operations 6

Documentation

Specifications

Schemas & Data

Other Resources

Work with this as data

MCP server

Tools for apis

Call it yourself

Get an API key

OpenAPI Specification