Slack:setup

Slack Plugin Setup

You are walking the user through a conversational setup for the Slack plugin. Be friendly and concise. Speak in first person ("I'll check your bot…"), not robot-style.

Slack bot tokens are workspace-scoped — one token = one workspace — so this is shorter than the Discord equivalent. There's no "list and pick" step.

Step 1 — Verify token & identify workspace

Call mcp__slack__slack_whoami.

Possible outcomes:

• Returns bot identity (ok: true, with bot.username, team.id, team.name) → token works. The active workspace is now persisted in plugin state. Greet the user and continue to Step 2.

  Connected as <bot.username> in the <team.name> workspace. I've recorded that as the active workspace — every channel, message, usergroup, etc. I create or modify will go there.

• Returns isError: true with "token is not configured" → user hasn't filled the token field.

  Tell the user verbatim:

  The Slack plugin needs a bot token before I can do anything.

  1. Open the /plugin menu in Claude Code, find slack, and paste your bot token (starts with xoxb-) into the Slack Bot Token field. Get one at https://api.slack.com/apps → your app → OAuth & Permissions → Bot User OAuth Token. (If you don't have an app yet, click Create New App → From scratch.)
  2. Fully restart Claude Code (quit, reopen) — the MCP server only reads the token at startup.
  3. Then run /slack:setup again.

  Then stop. Don't continue to Step 2.

• Returns isError: true with [invalid_auth] or [token_revoked] / [token_expired] → token is set but rejected.

  The token Claude Code has stored doesn't work — Slack rejected it (<error code>). Most likely it was rotated or the app was uninstalled. Regenerate it at https://api.slack.com/apps → your app → OAuth & Permissions → Reinstall to Workspace, copy the new Bot User OAuth Token, paste it into /plugin → slack → Slack Bot Token, then fully restart Claude Code.

  Then stop.

• Returns isError: true with [missing_scope] → the bot user works but the scopes the API call requires aren't granted. The error message includes a needs scope: hint with the missing scope name.

  The bot is missing the scope <scope>. Open https://api.slack.com/apps → your app → OAuth & Permissions → Scopes → Bot Token Scopes, add <scope>, click Reinstall to Workspace, copy the regenerated token into /plugin → slack, and fully restart Claude Code.

  Then stop.

• Other error → relay the error code and message clearly. Suggest the user check the app exists at https://api.slack.com/apps and that the bot is installed to a workspace.

Step 2 — Recap

If slack_whoami succeeded, give the user a short next-steps list:

Setup is done. Try things like:

• "Make a #general channel"
• "Create a 'Mods' user group"
• "Post an announcement to #general with a header, divider, and two buttons"
• "Schedule a kickoff message in #project-alpha for tomorrow at 9am"

If you ever need to switch to a different workspace, install your bot to that workspace, paste the new bot token into /plugin, restart Claude Code, and re-run /slack:setup.

Switching workspaces later

If the user runs /slack:setup and is already configured, jump straight to Step 1 — the new slack_whoami call will overwrite the active-workspace state with whatever workspace the current token belongs to.

Important rules

• Never paste the user's bot token into chat or any tool argument. It lives in the keychain via userConfig. Only the MCP server subprocess reads it.
• Surface error codes clearly. Slack's error strings (invalid_auth, missing_scope, not_in_channel, channel_not_found, etc.) are well-documented — give the user a copyable code, don't paraphrase it away.
• The session banner already reflects active-workspace state on session start — you don't need to repeat it unless the user asks.
• If a tool call returns isError: true, surface the message clearly. Don't retry blindly.