Slack MCP Tool
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Give your agents the ability to post messages to Slack channels and DMs via the MCP protocol.
The Slack MCP tool lets your agents post messages to Slack — channels, threads, and DMs. Unlike the Slack Work App (where users talk to agents in Slack), the MCP tool gives agents the ability to act on Slack as part of their workflows.
The Slack MCP tool requires an installed Slack workspace. Follow the installation guide first if you haven't set up the Slack app yet.
Create a Slack MCP tool
Open MCP Servers
Navigate to MCP Servers in the sidebar and click New MCP server.
Select Slack from Work Apps
Switch to the Work Apps tab and select the Slack card. If your organization has a Slack workspace installed, you'll see the channel configuration dialog.
If no workspace is installed, the dialog prompts you to install the Slack app first.
Configure channel access
Choose how the agent can interact with Slack:
| Setting | Description |
|---|---|
| Channel access mode | All channels — the agent can post to any channel where the bot is a member. Selected channels — restrict the agent to specific channels. |
| DM enabled | Whether the agent can send direct messages. Enabled by default. |
| Selected channels | When using "Selected channels" mode, pick from the list of channels where the Inkeep bot is a member. |
Channel access and DM access are independent — you can allow all channels but disable DMs, or allow selected channels and also enable DMs.
Create
Click Create to create the Slack MCP tool. It appears in your MCP servers list and can be added to any agent.
Available tools
The Slack MCP server exposes the following tools:
post-channel-message
Posts a message to a Slack channel.
post-direct-message
Sends a direct message to a Slack user.
The agent knows how to send a DM to the user asking the question out of the box — no additional prompting or configuration is required.
Edit channel access
To change channel access after creation:
- Open the Slack MCP tool from the MCP Servers list
- In the Slack Channel Access section, click Configure
- Update the channel access mode, DM toggle, or selected channels
- Click Save Changes
Access control
The MCP tool enforces access rules at runtime:
- Selected channels mode: The agent can only post to channels in the allowed list. Attempts to post to other channels are rejected.
- DM disabled: The agent cannot post to DM channels (channel IDs starting with
D). Enable the DM toggle to allow DMs. - All channels mode: The agent can post to any channel where the bot is a member.
Access configuration is per-tool — different agents can have different Slack MCP tools with different channel restrictions.