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insodimension/slack-user

v0.1.0MIT

Slack as you: search, read and send in your own name through Slack's official MCP server

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Slack (as you)

What it is

A connector that lets your Dimension agent search, read and send Slack messages as you, through Slack's official MCP server (mcp.slack.com). It uses your own sign-in, so it sees what you see and what it sends appears in your name. It is separate from the slack connector, which posts as a bot app. You bring your own Slack app: the Connect wizard gives you a one-click link that creates it from a ready-made manifest, and an optional "Set up with your agent" button that has the Browser plugin do the clicking while you watch.

What it contains

  • Tools: slack_tools (what Slack offers, straight from Slack), slack_read (read-only calls), slack_act (calls that change Slack; every call asks you first).
  • Skill: slack-user.
  • Rule: slack-user-context, always on, about sending in your name.
  • Connect flow: OAuth 2.0 with PKCE (no client secret by default; an optional field covers an app Slack rejects with bad_client_secret), three permission levels (Read only, Read and send, Everything), a verify probe against auth.test, and connect/slack-app-manifest.json, the manifest the setup link pre-fills.

Who can use it

Off by default. It needs a Slack workspace where you may create an app, or where an admin will approve one, and Slack's MCP server must be available to your app. The agent-assisted setup also needs the Browser plugin; the manual steps work without it. Loads in every space.

Limits and risks

  • It acts as you. A sent message cannot be silently unsent. slack_act always asks before running, in every approval mode, and shows the Slack tool, its arguments (the channel and the text) and the account it acts as. The account is named once Slack has been asked who you are, which slack_tools and slack_read do; before that the prompt says "the connected Slack account".
  • It can read everything you can read, including private channels and DMs, within the permission level you choose at Connect.
  • Slack decides what the MCP server offers. slack_tools reads the list at run time, and a tool counts as read-only only if Slack marks it so.
  • The sign-in is stored in ~/.config/dimension-slack-user/token.json on this machine. Slack rotates it; an app left unused for about 30 days can be signed out, and you click Connect again.
  • Slack allows its MCP server only for apps it lists or for internal apps; a workspace may require an admin to approve yours.

Build and test

bun test marketplace/packs/slack-user

Run from the Dimension monorepo root. The tests use a local fake of Slack's MCP server and token endpoint and never call Slack.