EditorMu Grammar
Engineer & Idea Maker · 2026
A macOS menu-bar utility that fixes grammar and generates AI-powered reply suggestions anywhere you type — in any app, any text field, system-wide. Supports hosted free tier (Firebase Auth + OpenAI backend), bring-your-own OpenAI key, or fully local Ollama models.
Problem & Approach
Switching between apps to fix grammar or craft a reply breaks your flow. Copy text, open ChatGPT, paste, copy back — it's slow and disruptive. Existing grammar tools either require browser extensions that only work in certain apps, or they replace your entire writing style. There was no lightweight, system-wide tool that works in every app and stays out of your way.
Solutions & Impact
EditorMu Grammar lives in your menu bar and intercepts two shortcuts globally. ⇧⌘G captures your selected text and returns three grammar-corrected versions (Corrected, Polished, Concise) in a floating popup — click one to replace in place. ⌥⌘R opens a Reply Assistant: type your intent or pick a preset, and get three reply suggestions (Professional, Friendly, Brief) generated in parallel. Built using CGEventTap and Accessibility APIs to work in any app without browser extensions or clipboard hacks.
Learning & Reflection
This project pushed me deep into macOS system programming — CGEventTap for global hotkeys, AXUIElement for reading and replacing selected text across apps, and ASWebAuthenticationSession with PKCE for OAuth without Xcode. I also built the full backend stack: Firebase Auth, Firestore usage tracking, OpenAI proxy, and Ko-fi webhook integration, all deployed on Vercel. The biggest lesson was designing a non-activating NSPanel that floats over other apps without stealing keyboard focus — a subtle but critical UX constraint.