agent-device is an open-source tool from Callstack that lets an AI agent drive iOS and Android apps and check what is on screen. This post covers why it was picked for testing a Flutter app, how to install it for Claude Code, the basic command loop, and what to watch out for with Flutter. It is based on version 0.21.31 (2026-10-24).

Why agent-device

Flutter ships Android and iOS apps from one codebase, so the device-testing tool has to cover iOS too. Google Artemis, the first candidate, is a natural-language testing agent, but it supports Android only; iOS is still just a roadmap item.

The other candidates looked like this:

mobile-mcp exposes taps, screenshots, and the accessibility tree on iOS and Android over MCP (the protocol an AI uses to call external tools). It has no sessions, replay, or evidence storage, so a verified flow is hard to hand off to CI.

Maestro is an E2E framework that pins flows in YAML, and it has an MCP server.…