Eyes, ears, and hands for AI-assisted 모바일 개발.

Quern은 AI 코딩 에이전트 - Claude Code, Cursor, Windsurf 및 기타를 만들 수있는 로컬 디버그 서버입니다. 실제로 see 앱이 무엇을하고 있는지 확인하십시오. 로그, 네트워크 트래픽, 충돌 보고서, 스크린 샷, UI 상태 : 스택 추적 및 stale 오류 메시지에서 추측하는 대신 에이전트는 장치에서 일어나는 모든 것에 대한 실시간 구조 접근을 가져옵니다.

구름 없음. 원격 측정 없음. 그냥 Mac에서 데몬은 "가장 성공"과 “실제로 작동합니다.”

지원 iOS 시뮬레이터, 물리적 iOS 장치 (WebDriverAgent를 통해), 안드로이드 에뮬레이터 및 물리적 안드로이드 장치.

왜

AI 에이전트는 작성 코드에 좋습니다. – 특히 모바일 기기에서 작동하는지 알 수 있습니다. 빌드 오류가 잡혔습니다. 침묵하는 API 실패, 잘못된 화면, 또는 실행에 충돌은 일반적으로 작동하지 않습니다. 채팅으로 다시 로그를 붙여 넣으면.

Quern은 그 루프를 닫습니다.

Quern

Eyes, ears, and hands for AI-assisted mobile development.

Quern is a local debug server that lets AI coding agents — Claude Code, Cursor, Windsurf, and others — actually see what your app is doing. Logs, network traffic, crash reports, screenshots, UI state: instead of guessing from stack traces and stale error messages, your agent gets live, structured access to everything happening on the device.

No cloud. No telemetry. Just a daemon on your Mac that bridges the gap between “build succeeded” and “it actually works.”

Supports iOS simulators, physical iOS devices (via WebDriverAgent), Android emulators, and physical Android devices.

Simulator / Device
    │
Quern (localhost:9110)
    ├── Log capture (device, simulator, crash reports, build output)
    ├── Network proxy (intercept, mock, replay HTTP traffic)
    ├── Device control (boot, screenshot, tap, swipe, type)
    │
    ├── HTTP API ──→ Any tool or script
    └── MCP tools ──→ Claude Code, Cursor, etc.

Why

AI agents are good at writing code. They’re bad at knowing whether it worked – especially on mobile devices. A build error gets caught; a silent API failure, a wrong screen, or a crash on launch usually doesn’t — unless you paste logs back into the chat yourself.

Quern closes that loop. It gives agents direct, token-efficient access to everything they need to diagnose and fix problems autonomously: structured logs, network request/response pairs, parsed crash reports, screenshots, and the ability to interact with the running appon a simulator or real device.

Quern isn’t a cloud testing platform. It’s local infrastructure that makes the AI tools you already use actually effective at debugging and testing mobile apps.

• Local-first — No cloud, no accounts, no third-party API keys. Your code and logs never leave your machine, unless you point quern at another Mac you’ve paired with.
• Works with your existing AI — Not a replacement for Claude, Cursor, or Codex. It makes them better by giving them live access to what your app is actually doing.
• Built for your editor and CLI — Designed for agents already in your workflow, not a separate QA portal.
• Great for QA and SDET workflows — Pair with an agent during manual testing. Let it intercept network calls, mock error responses, or verify analytics payloads while you drive the app — no more juggling Charles Proxy and a terminal.
• Free and open source — Apache 2.0 licensed. Run it free, forever, on your own hardware.

Podcast

https://github.com/user-attachments/assets/885cda62-9355-41d9-a4fd-b989f7b90940

A 20-minute deep dive generated by Google NotebookLM from the Quern repository. Good overview of the architecture and use cases. This is definitely ‘AI slop’, and may be either useful, entertaining, or horrifying for you to listen to. You have been warned; choose wisely.

How to Use Quern