0n3
MCP servers · Slack · connector · GPT action

Connect ChatGPT to Slack

One line gives ChatGPT 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 ChatGPT's access alone any time.

Get the line for ChatGPTConnect Slack first

Three steps

  1. Create a free 0n3 account and connect Slack. Paste a key or sign in; it lands in your vault, encrypted.
  2. Install 0n3 into ChatGPT. A custom connector in Developer mode, or an Action on a custom GPT from the OpenAPI spec.
  3. Ask ChatGPT: whoami. Then: "Send a message in Slack".
Custom connector (needs Developer mode)
  1. Settings → Connectors (or Apps) → Advanced → Developer mode on
  2. Create → name 0n3 · MCP server URL https://0n3.app/mcp · Authentication: OAuth
  3. Finish the sign-in with your 0n account
  4. Enable the connector in a chat and ask: "whoami"

ChatGPT connectors cannot send a static header, so 0n3 signs you in through its OAuth door (dynamic client registration is on).

The line above carries a placeholder; 0n3.app/install mints a real key named for ChatGPT and fills it in.

What ChatGPT can then do in Slack

Send message · Post, update, delete, and schedule messages7
Send a messagePOST /chat.postMessage
Update a messagePOST /chat.update
Delete a messagePOST /chat.delete
Schedule a messagePOST /chat.scheduleMessage
Pin messagePOST /pins.add
Unpin messagePOST /pins.remove
Search messagesGET /search.messages
Channels · Full channel lifecycle management13
List channelsGET /conversations.list
Create a channelPOST /conversations.create
Archive a channelPOST /conversations.archive
Unarchive channelPOST /conversations.unarchive
Rename channelPOST /conversations.rename
Set a channel topicPOST /conversations.setTopic
Set a channel purposePOST /conversations.setPurpose
Invite a to channelPOST /conversations.invite
Kick from channelPOST /conversations.kick
Channel historyGET /conversations.history
Channel infoGET /conversations.info
Join channelPOST /conversations.join
Threads · Thread replies and conversation management2
Reply a to threadPOST /chat.postMessage
Get thread repliesGET /conversations.replies
Users · List users, get profiles, set status4
List usersGET /users.list
Get an userGET /users.info
Get an user profileGET /users.profile.get
Set an user statusPOST /users.profile.set
Files · Upload, list, delete, and share files5
Upload a filePOST /files.upload
List filesGET /files.list
Delete a filePOST /files.delete
Share filePOST /files.sharedPublicURL
Search filesGET /search.files
Reactions · Emoji reactions on messages3
Add a reactionPOST /reactions.add
Remove a reactionPOST /reactions.remove
List reactionsGET /reactions.get

All 45 Slack endpoints →

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ChatGPT with other apps

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