Connect AI to your Slack workspace — choose between Claude Desktop (quick setup) or Gemini CLI with MCP (more hands-on).
Before we start summarising, let’s get your tools connected to Slack. Choose the path that suits you best.
You will need: a laptop with internet access and a Slack workspace where you are a member. No coding experience is required — we will guide you through every step.
Download the app for your operating system (Windows or macOS)
Install it by opening the downloaded file and following the prompts
Open Claude Desktop and create a free account (or sign in if you already have one)
Do I need a paid plan?
No. The free plan includes access to Slack connectors. You can start summarising channels right away without paying anything.
2
Connect Slack
In Claude Desktop, click your profile icon in the bottom-left corner
Click Customize
Click Connectors
Click the + button to add a new connector
Find Slack in the list and click it
A browser window will open — sign in to your Slack workspace
Review the permissions and click Allow
Return to Claude Desktop — Slack is now connected
What does the connector do? It gives Claude secure, read-only access to your Slack messages. Claude can search and read messages in channels you have access to, but it cannot post, delete, or modify anything.
I don't see the Connectors option
Make sure you are using the latest version of Claude Desktop. Go to Help → Check for Updates and install any available updates. If you still don’t see it, try signing out and signing back in.
The Slack authorisation window won't open
Check that your browser is not blocking pop-ups. Try a different browser if the window still won’t appear. You can also try copying the authorisation URL and pasting it directly into your browser.
3
Test the connection
In the Claude Desktop chat, type this prompt:
Copy this prompt
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List the Slack channels you can see in my workspace.
You should see a list of channel names from your Slack workspace. If you do, the connection is working.
Claude says it cannot access Slack
Go back to Customize → Connectors and check that Slack shows as connected. If it shows an error, remove the connector and add it again. Make sure you authorise the correct workspace.
This path gives you more hands-on experience. You will install Gemini CLI, create a Slack App, and configure a Model Context Protocol (MCP) server to connect them. This takes about 30 minutes.
1
Install Node.js
Already have Node.js? If you installed it for a previous tutorial, skip this step. Run node --version in your terminal to check — you should see a version number like v22.x.x.
Node.js is a free tool that lets you run Gemini CLI on your computer.
Click the big green LTS button to download the installer
Open the downloaded .pkg file
Click Continue through all the screens — the default settings are fine
Click Install, then Close
How do I know it worked?
Open your terminal and type:
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node --version
You should see a version number like v22.x.x. If you see an error, try closing and reopening your terminal, then run the command again.
2
Install and test Gemini CLI
Already have Gemini CLI? If you installed it for a previous tutorial, skip this step. Just run gemini in your terminal to check it still works.
Gemini CLI is Google’s free AI assistant. It runs in your terminal and helps you with tasks based on your descriptions.Open your terminal and type:
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npm install -g @google/gemini-cli
Wait for the installation to finish. Then start it by typing:
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gemini
The first time you run it, Gemini CLI will ask you to sign in:
Choose “Sign in with Google”
A browser window will open — sign in with your Google account
Come back to the terminal when it says you’re connected
Free tier: 60 requests per minute, 1,000 requests per day — more than enough for this tutorial and everyday use.
'npm' is not recognised
This means Node.js isn’t installed correctly. Go back and reinstall Node.js. After reinstalling, close your terminal completely and open a new one before trying again.
Permission denied error
Windows: Close PowerShell and reopen it by right-clicking and choosing “Run as Administrator”. Then try the install command again.macOS: Add sudo before the command:
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sudo npm install -g @google/gemini-cli
Enter your computer password when prompted (you won’t see characters as you type — that’s normal).
Type /quit to exit Gemini CLI for now. We will start it again after configuring the Slack connection.
3
Create a Slack App
A Slack App is how you give Gemini CLI permission to read messages from your workspace. The app you are creating will only have read-only access — it cannot post, delete, or change anything.
A Slack App is like giving a programme a key to your workspace. The key only opens the doors you choose — in this case, the ability to read messages in public channels. The app cannot see your direct messages, cannot post anything, and cannot change any settings.
4
Add permissions (scopes)
Now you need to tell Slack exactly what the app is allowed to do.
In the left sidebar, click OAuth & Permissions
Scroll down to the Scopes section
Under Bot Token Scopes, click Add an OAuth Scope
Add these two scopes:
channels:history — lets the app read messages in public channels
channels:read — lets the app see which public channels exist
Only add these two scopes. They give the app read-only access to public channels. The app cannot read private channels, direct messages, or post anything.
What are scopes?
Scopes are permissions. They control exactly what your app is allowed to do. Think of them like keys — channels:history is the key that opens message history, and channels:read is the key that lets the app see channel names. Without these specific keys, the app cannot do anything.
5
Install the app and get your bot token
Scroll to the top of the OAuth & Permissions page
Click Install to [Your Workspace Name]
Review the permissions and click Allow
You will see a Bot User OAuth Token that starts with xoxb-
Copy this token and save it somewhere safe — you will need it in Step 7
This token is like a password. Anyone who has it can read messages in your workspace. Do not share it publicly or post it online. Save it in a text file or password manager.
How do I know it worked?
You should see a long token starting with xoxb- on the OAuth & Permissions page. If you see an error, check that you added both scopes in Step 4, then try clicking Install to Workspace again.
6
Get your Team ID
The Team ID identifies your Slack workspace. You need it for the MCP configuration.
Open Slack in your web browser (not the desktop app) at app.slack.com
Sign in to your workspace
Look at the URL in your browser — it will look like: https://app.slack.com/client/T01234567/...
The Team ID is the part that starts with T — for example, T01234567
Copy this ID and save it alongside your bot token
I can't find the Team ID in the URL
Another way: In Slack, click your workspace name in the top-left corner → Settings & administration → Workspace settings. The Workspace ID (which is the same as Team ID) is usually shown on the settings page, or in the URL of the settings page.
7
Configure Slack MCP in Gemini CLI
Now you will connect Gemini CLI to Slack by configuring a Model Context Protocol (MCP) server. This tells Gemini CLI how to talk to Slack.
Windows
macOS
Open File Explorer
In the address bar, type %USERPROFILE%\.gemini and press Enter
If you see a file called settings.json, open it with Notepad
If the file does not exist, create a new text file and name it settings.json
Open Finder
Press Cmd + Shift + G and type ~/.gemini then press Enter
If you see a file called settings.json, open it with TextEdit
If the file does not exist, open Terminal and run:
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touch ~/.gemini/settings.json && open -e ~/.gemini/settings.json
Paste the following into settings.json. Replace the two placeholders with your actual bot token and Team ID:
~/.gemini/settings.json — replace YOUR_BOT_TOKEN and YOUR_TEAM_ID
Replace two things:xoxb-YOUR_BOT_TOKEN with your full bot token (e.g., xoxb-1234-5678-abcdef) and YOUR_TEAM_ID with your Team ID (e.g., T01234567). Keep the quotation marks.
If settings.json already has content from a previous tutorial, you need to merge the configurations. Add the "slack" section inside the existing "mcpServers" block rather than replacing the entire file.
Save the file.
What is MCP?
MCP stands for Model Context Protocol. It is a standard way for AI tools to connect to external services like Slack, GitHub, or databases. Think of it as a universal adapter — instead of each AI tool building its own Slack connection, they all use MCP. You configure it once, and the AI can read your Slack messages.
8
Add the bot to a channel
The bot needs to be a member of a channel before it can read messages from it.
Open Slack (desktop app or browser)
Go to the channel you want to summarise
Type /invite @Channel Summariser (or whatever you named your app) and press Enter
You should see a message confirming the bot has been added
Choose an active channel with at least 10–20 recent messages. This gives the AI something meaningful to summarise. You can always add the bot to more channels later.
The bot doesn't appear when I type /invite
Make sure you spell the app name exactly as you created it. You can also add the bot by clicking the channel name at the top → Integrations → Add an App, then find your app in the list.
9
Test the connection
Open your terminal and start Gemini CLI:
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gemini
The first time Gemini CLI loads with MCP configured, it may take a moment to connect to the Slack server. Once it’s ready, type this test prompt:
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Use the Slack tools to list the public channels in my workspace.
You should see a list of channel names from your Slack workspace. If you do, everything is working.
Gemini says it has no Slack tools available
Check your settings.json file for typos. The most common issues are:
Missing commas between fields
Incorrect quotation marks (use straight quotes ", not curly quotes)
Wrong file location — it must be in ~/.gemini/settings.json
After fixing, close Gemini CLI (/quit) and start it again.
Connection error or timeout
Make sure Node.js is installed correctly (node --version should show a version number). The MCP server uses npx to run, which comes with Node.js. If npx is not found, reinstall Node.js.
'invalid_auth' error
Your bot token is incorrect. Go back to api.slack.com/apps, find your app, go to OAuth & Permissions, and copy the Bot User OAuth Token again. Update your settings.json with the correct token.
