Documentation

Slack

Post messages, browse channels, look up users, upload files, and search the workspace in Slack.

The Slack integration lets your assistant participate in a Slack workspace — posting messages and threads, discovering channels and users, and sharing files from your resources. Workspace-wide message search is a separate connection (Slack blocks bot tokens from searching), so it’s covered below as its own step.

Connect it

Slack uses OAuth. Connecting installs a bot token (xoxb) for the four core tools. To use Search Messages you additionally connect Slack Search, which adds a user token (xoxp) — Slack requires a user token for search.messages.

Core tools

• Send Message — posts to a channel, DM, or thread. channel accepts an ID (C…/G…/D…, preferred) or a name (#general); set threadTs to reply inside an existing thread. Text uses Slack’s mrkdwn by default. Returns the message ts so later replies can thread onto it.
• List Channels — lists conversations the token can see (public by default; include private channels, group DMs, or DMs via types). Returns name, member count, topic, and channel ID. Use it to resolve a channel name to an ID before posting.
• Get User — looks up a user by userId or email (pass exactly one). Returns the ID, display and real name, email (if visible), and active/bot flags. Use it to turn a mention or email into a Slack ID.
• Upload File — shares a stored resource into a channel via Slack’s external-upload flow. Takes resourceUri, the destination channel, and an optional initialComment and threadTs. Up to 100 MB per file. Use this rather than Send Message when sharing a document or image.

Searching the workspace

Message search is a separate integration — Slack Search — because Slack blocks bot tokens from searching and requires a user token. Connect it to add the Search Messages tool, then search to find prior context before replying with Send Message.

Last updated July 6, 2026