Slack Proofreader

Proofread your Slack messages with Claude before sending. Adds a Proofread button to the Slack message composer that checks grammar, spelling, and clarity.

Prerequisites

• Node.js (v18+)
• Claude CLI installed and authenticated

Setup

git clone <repo-url>
cd slack-proofreader
npm start

This installs dependencies and starts the local bridge server on port 52983.

Then load the Chrome extension:

1. Open chrome://extensions in Chrome
2. Enable Developer mode (top right toggle)
3. Click Load unpacked
4. Select the extension/ folder from this repo

Open Slack in Chrome, type a message, and click the Proofread button next to the send button.

How it works

[Slack composer] --click Proofread--> [Chrome extension]
    --POST text--> [Local server :52983]
        --claude -p--> [Claude CLI]
    <--proofread text--
[Popup: Original vs Suggested] --click Replace--> [Text replaced in composer]

The local server is needed because Chrome extensions can't run shell commands. It receives your message text, passes it through claude -p (Claude CLI's pipe mode), and returns the proofread version. Everything runs locally.