axiom-xcode-mcp
Xcode MCP
You MUST use this skill for ANY Xcode MCP interaction — setup, tool usage, workflow patterns, or troubleshooting.
Xcode ships an MCP server exposing IDE tools to external AI clients. xcrun mcpbridge is the stdio transport clients register, available since Xcode 26.3. Xcode 27 adds an explicit "Allow external agents to use Xcode tools" gate, the run-agent launch path, an agent-extension model (custom MCP servers, skills, plug-ins), and a headless server. This skill suite covers setup, tool reference, workflow patterns, and troubleshooting.
On Xcode 26.x, mcpbridge requires a running Xcode with a project open. If that's a liability, the device/simulator half of these operations has a fully Xcode-independent CLI path: devicectl + simctl + Axiom's xcui/xclog/xcsym/xcprof. See axiom-tools (skills/device-control-ref.md).
That constraint is gone on Xcode 27. xcrun mcp-server runs the tool service with Xcode.app closed — sudo xcrun mcp-server enable, then start and open <path>. Clients still register xcrun mcpbridge; the bridge is the transport, mcp-server is the service. Apple's tool schemas describe workspaceIdentifier as "used in headless mode", so headless is a supported model rather than a workaround.
Choose between MCP and the CLI tools (devicectl, simctl, and Axiom's xcui/xclog/xcsym/xcprof) on capability, not uptime. xcui asserts, waits, toggles accessibility settings, and computes VoiceOver announcements, and none of them need sudo — which still matters in CI, where the headless server's sudo opt-in may not be available. The IDE-authoring tools (build state, render previews) remain MCP-only; xcodebuild builds and tests but does not render previews.