MCP servers · Slack · connector
Connect Claude (desktop & claude.ai) to Slack
One line gives Claude (desktop & claude.ai) your Slack account as tools: 45 endpoints, send message, channels, threads, called with your own connection. No key in the prompt, a receipt for every call, revoke Claude (desktop & claude.ai)'s access alone any time.
Three steps
- Create a free 0n3 account and connect Slack. Paste a key or sign in; it lands in your vault, encrypted.
- Install 0n3 into Claude (desktop & claude.ai). Add 0n3 as a custom connector; sign in once through the 0n door.
- Ask Claude (desktop & claude.ai): whoami. Then: "Send a message in Slack".
Claude desktop app and claude.ai
- Settings → Connectors → Add custom connector
- Name: 0n3 · URL: https://0n3.app/mcp
- Click Connect and sign in with your 0n account (email + password, or paste your 0n token)
- Turn the connector on in a chat and ask: "whoami"
This is the OAuth door: no token to paste, revoke it any time from 0n3 → Tokens.
The line above carries a placeholder; 0n3.app/install mints a real key named for Claude (desktop & claude.ai) and fills it in.
What Claude (desktop & claude.ai) can then do in Slack
Send message · Post, update, delete, and schedule messages7
Send a message
POST /chat.postMessageUpdate a message
POST /chat.updateDelete a message
POST /chat.deleteSchedule a message
POST /chat.scheduleMessagePin message
POST /pins.addUnpin message
POST /pins.removeSearch messages
GET /search.messagesChannels · Full channel lifecycle management13
List channels
GET /conversations.listCreate a channel
POST /conversations.createArchive a channel
POST /conversations.archiveUnarchive channel
POST /conversations.unarchiveRename channel
POST /conversations.renameSet a channel topic
POST /conversations.setTopicSet a channel purpose
POST /conversations.setPurposeInvite a to channel
POST /conversations.inviteKick from channel
POST /conversations.kickChannel history
GET /conversations.historyChannel info
GET /conversations.infoJoin channel
POST /conversations.joinThreads · Thread replies and conversation management2
Reply a to thread
POST /chat.postMessageGet thread replies
GET /conversations.repliesUsers · List users, get profiles, set status4
List users
GET /users.listGet an user
GET /users.infoGet an user profile
GET /users.profile.getSet an user status
POST /users.profile.setFiles · Upload, list, delete, and share files5
Upload a file
POST /files.uploadList files
GET /files.listDelete a file
POST /files.deleteShare file
POST /files.sharedPublicURLSearch files
GET /search.filesReactions · Emoji reactions on messages3
Add a reaction
POST /reactions.addRemove a reaction
POST /reactions.removeList reactions
GET /reactions.getSlack in other AI clients
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