Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| SLACK_MCP_ADD_MESSAGE_TOOL | No | Controls message posting capability. Set to '*' to enable for all channels, or provide comma-separated channel IDs (e.g., 'C1234567890,C9876543210') to enable for specific channels. If not set, message posting is disabled by default. |
Schema
Prompts
Interactive templates invoked by user choice
| Name | Description |
|---|---|
No prompts | |
Resources
Contextual data attached and managed by the client
| Name | Description |
|---|---|
No resources | |
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
| conversations_history | Retrieves message history from a Slack channel, DM, or thread. Supports pagination and filtering. |
| conversations_replies | Fetches all messages in a specific thread by channel and thread timestamp. Supports pagination. |
| conversations_add_message | Posts a message to a channel, thread, or DM. Supports markdown and plain text. NOTE: Disabled by default for safety - set SLACK_MCP_ADD_MESSAGE_TOOL environment variable to enable. |
| channels_list | Lists workspace channels by type (public, private, DMs, group DMs) with optional popularity sorting. Supports pagination. |