Claude AI in Slack: Summarize Threads, Review Code, and Fix Bugs with a PR

What if you could ask Claude to fix all the bugs in your GitHub repo — without leaving Slack?

One message. It clones the repo, finds the bugs, fixes them, and opens a pull request. I'll show you exactly how to set this up and walk you through three real demos.

What You'll Be Able to Do

By the end of this guide, you'll have Claude working inside your Slack workspace to:

• ✅ Summarize threads and extract action items instantly
• ✅ Review code snippets pasted directly in a channel
• ✅ Analyze your entire GitHub repo, fix bugs, and create a PR — all from one message

Prerequisites

Before we start, you'll need:

• A Slack workspace where you have permission to install apps
• A Claude Pro or Max plan (Claude Code routing requires this)
• At least one GitHub repo connected on claude.ai/code

Step 1: Install Claude in Your Slack Workspace

Open Slack and click the More button in the left sidebar. Go to Tools → Apps to open the Slack Marketplace.

Search for Claude and click on it. Click Add to Slack, which will open your browser. Review the permissions and click Allow — make sure the correct workspace is selected.

Once installed, you'll see the Claude app appear in your Slack sidebar.

Step 2: Connect Your Claude Account

Click on the Claude app in Slack. You'll see a message: "To use Claude, you need to connect your Claude AI account."

Click the button, which opens your browser. If you're already logged into Claude, it'll show a permission page — just click Authorize.

You'll see a success message, and you're connected.

Step 3: Configure Routing Mode

This step is critical. Go to the Home tab of the Claude app in Slack.

Set Routing Mode to Code + Chat.

This is what lets Claude handle both regular questions AND coding tasks. Without this, Claude won't route to Claude Code for repository work.

While you're here, choose your preferred model. I use Opus, but Sonnet or Haiku work too depending on your plan.

Step 4: Connect Your GitHub Repo

Go to claude.ai/code and click Select Repository. If it's your first time, you'll need to install the Claude GitHub app first.

Once the app is installed, select the repository you want Claude to work with. This is the repo Claude will be able to clone, read, and modify when you ask it to from Slack.

Demo 1: Summarize a Thread in 5 Seconds

This one is immediately useful for any team.

In a Slack channel (Claude needs to be invited first — just click the invite button or type /invite @Claude), tag Claude and ask:

@Claude summarize this thread and list any action items

In about 5 seconds, Claude reads the entire thread and returns a clean summary with action items. If you've ever joined a channel with 50 unread messages, this becomes your best friend.

Note: For the first message in a channel, Claude needs to be added to that channel. You'll get a prompt to do so automatically.

Demo 2: Code Review Without Leaving Slack

Paste a code snippet directly into Slack and ask Claude to review it:

router.get('/:id', (req, res) => {
  const user = users.find(u => u.id === req.params.id);
  res.json(user);
});

Then tag Claude:

@Claude review this code — why might it return undefined for a valid user ID?

Claude identified the bug instantly: req.params.id is a string, but the user IDs are numbers. The strict comparison (===) always fails because "1" !== 1.

No copy-pasting to ChatGPT, no context-switching to another tab. Just paste and ask.

Demo 3: Fix Your Entire Repo from Slack (The Star)

This is where it gets impressive.

Tag Claude in a channel and give it your repo:

@Claude look at this repo: https://github.com/your-username/your-repo
Find all the bugs in the code and fix them.

Watch what happens:

1. Claude responds: "Working in your-username/your-repo" — it's routing to Claude Code
2. It clones the repo and starts reading all the files
3. It posts progress updates in the Slack thread
4. When done, it lists every bug it found, where it was, and what it fixed
5. You get two buttons: View session and Create PR

In my demo, it found four bugs automatically:

• String-to-number comparison bug in the GET endpoint (req.params.id vs number IDs)
• Same issue in the DELETE endpoint
• No input validation on the POST endpoint
• Broken ID generation

Click View session to see the full Claude Code web session — every file it read, every fix it made.

Click Create PR — one click, and there's a GitHub pull request with all the fixes.

From a Slack message to a GitHub PR. That's the workflow.

Important Limitations to Know

Sessions don't persist across messages. Each time you tag Claude with a new message in Slack, it starts a fresh session. If you need follow-up work on the same repo, do it inside the Claude Code web session that opens (click "View session") — not back in Slack.

After some time, the session will expire and close automatically. You'll receive a notification when this happens.

Channels only, not DMs. Claude Code routing only works in channels, not in direct messages.

Plan requirement. You need a Claude Pro or Max plan with GitHub connected for the Claude Code routing feature.

Quick Setup Checklist

• Claude app installed in Slack workspace
• Claude account connected (App Home → Connect button)
• Routing Mode set to Code + Chat in App Home
• GitHub repo connected on claude.ai/code
• Claude invited to the channel you want to use

What This Changes

The traditional workflow: copy code, open ChatGPT tab, paste, get answer, go back to Slack, implement.

The new workflow: paste code in Slack, tag Claude, get answer in the thread.

For repository-level work, it goes even further: one message triggers a full code analysis and a pull request.

This is what AI-native development looks like — AI embedded in the tools you already use, not a separate tab you have to context-switch to.

Questions? Drop a comment on the video — I read every one.