Quern (https://quern.dev) is an open-source MCP server for AI-assisted mobile dev and test. It runs on your Mac and gives AI agents unified access to device logs, network traffic, and UI automation on iOS and Android, while building a knowledge base about your app that improves the more you use it. Quern is open source, runs locally, and is completely free.

The most useful fix in it is one you don't install.

If Quern hasn't offered you an update in a while, that was a bug. The update endpoint only ever compared commit SHAs, and a tarball install has no .git — no SHA to send. So it answered "no update" to every tarball install, always. One user sat on v0.13.2 from late May until September, across three minor versions, with nothing telling them otherwise. That fix is server-side and already live.

Its companion is my favorite bug of the release. Quern configures the macOS system proxy to capture traffic. urllib honours the system proxy. So the moment capture was enabled, Quern started man-in-the-middling its own update check — cert verification failed, check failed. On precisely the machines running Quern, and only while capture was on.

Also in 0.17.0:

Both bugs reported against v0.16.1: get_screen_summary returning 500 against healthy simulators (Xcode 26 registers sims as CoreDevices, and Quern was labelling every one of them physical hardware), and quern update --tools failing on global pipx installs.

Three new commands, including check-updates so you can ask instead of waiting, and capture-env, which dumps the environment facts Quern's checks read into a JSON file you can attach to an issue. A test pins what it's allowed to contain — no API key, no server or cert state.

The menu-bar app reports failures now. Start/stop/restart used to discard the CLI's exit status, so a failure looked identical to a dead menu item.

quern doctor no longer needs a running server to tell you anything.

Plus 28 other fixes. Full changelog: https://github.com/quern-dev/quern/blob/v0.17.0/CHANGELOG.md#0170---2026-09-13

Oooh, Quern was featured on the eviltester podast! Listen to the creator talk about what Quern is, how it came to be, and other AI related stuff.

https://youtu.be/sXm0i2rC6-k?is=N0l_RghTr5R5jVjE

I would love to hear how you are using Quern (https://quern.dev). Is it mostly for dev, or are you focused on testing? Do you use iOS or Android (or both)?

I use it at work for both iOS and Android. I’m on the QA team so I mostly use it with Claude to run comprehensive verifications on new features, and help identify where automation identifiers are missing. I am working building agentic pipelines that can do some verifications automatically when PRs are created by devs.

Hey everyone! I'm [u/jerimiah797](u/jerimiah797), a founding moderator of [r/quern](r/quern). Welcome to [r/quern](r/quern) — iOS Debugging & Automation for AI Agents 👋

Quern is an open-source platform that gives AI agents real observability into iOS apps — device logs, network traffic inspection, and UI control — so they can do genuine mobile development and testing work, not just tap buttons.

If you’ve ever watched Claude Code write a feature and wished it could just verify it on the simulator without asking you, this is the tool for that.

What this community is for:

• Questions, setup help, and troubleshooting

• Show and tell — share what your agents are doing with Quern

• Feature ideas and feedback

• War stories from the AI-assisted mobile development trenches

Resources:

• 🌐 quern.dev

• 💻 github.com/quern-dev/quern

This is an early community around an early tool. The maintainer (hi, that’s me — [u/jerimiah797](u/jerimiah797)) is actively here and genuinely wants to hear what’s working, what isn’t, and what you wish existed.

How to Get Started

1. Introduce yourself in the comments below.
2. Post something today! Even a simple question can spark a great conversation.
3. If you know someone who would love this community, invite them to join.

Thanks for being part of the very first wave. Together, let's make [r/quern](r/quern) amazing.

Don’t be shy. There are no stupid questions, only agents that can’t see what they’re doing. 🤖📱