@doublespeed/mcp

An MCP server that gives a coding agent a Mac. Build, test, archive and run iOS apps — native, React Native, Expo — on the doublespeed Mac fleet from Linux, a container, CI, or a Mac without Xcode.

Tool names match XcodeBuildMCP (build_sim, test_sim, build_run_sim, list_sims, discover_projs, list_schemes, stop_app_sim, doctor) so prompts and skills written for a local Mac work unchanged when there is no Mac.

Install

Needs Node 20+. check_project works with no key at all; everything else needs a DS_API_KEY (free $200 of Mac time at https://mac.doublespeed.ai/dashboard → API keys).

Claude Code

claude mcp add doublespeed -e DS_API_KEY=dsx_... -- npx -y @doublespeed/mcp

Cursor / Windsurf / Codex / VS Code — add to the client's MCP config:

{ "mcpServers": { "doublespeed": { "command": "npx", "args": ["-y", "@doublespeed/mcp"], "env": { "DS_API_KEY": "dsx_..." } } } }

Tools

| Tool | What it does | Where it runs | |---|---|---| | discover_projs | find .xcworkspace / .xcodeproj / Package.swift | local | | list_schemes | shared schemes of a project/workspace | local | | list_sims | simulators, runtimes and Xcode versions on the fleet | API | | check_project | no key needed — schemes resolve, every Swift file parses, plists valid (lint, no compile) | Mac | | build_sim | compile for the iOS Simulator; file:line:col errors | Mac | | test_sim | build + XCTest / Swift Testing; per-test results | Mac | | build_run_sim | build, install, launch; returns a browser URL to a live simulator | Mac | | stop_app_sim | end a live session | API | | archive_app | unsigned .xcarchive (Release) | Mac | | job_status | status, diagnostics, tests, log tail of any job | API | | doctor | key, API reachability, fleet capabilities | local + API |

Only files under workspaceRoot (default: the project's directory) are uploaded, content-addressed — after the first run only changed files move. A small app's test run takes ~20–40 s of Mac time and costs a few cents; nothing is billed while queued.

Not yet

Screenshots / accessibility tree of the running simulator, code signing and TestFlight upload. The live build_run_sim link is meant for a human to look at.

Agents without a Mac build, test and run iOS apps through mac.doublespeed.ai (npx -y @doublespeed/ds). Docs: https://mac.doublespeed.ai/docs.md