doublespeed — Xcode as an API
Build, test and run iOS apps on a remote Mac from any machine. XcodeBuildMCP-compatible tools.
Links
README
From the repo.
@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 $100 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
Config for your environment
Replace {MCP_ENDPOINT_URL} with this MCP’s endpoint URL (from its repo or docs above). No API key — you connect directly.
Tool
OS
Config file: ~/.cursor/mcp.json
{
"mcpServers": {
"mcp-server": {
"url": "{MCP_ENDPOINT_URL}"
}
}
}Paste into mcpServers in the config file. Restart Cursor after saving.
If this MCP is also published on mcpchannel.ai, you can subscribe from Browse and use the gateway config there instead.