[Bug]: simulatorId being persisted in config file

[jorgealegre]

Bug Description

I have a shared configuration file for my team to work on the same project using Cursor and XcodeBuildMCP. I want to declare that we should all run on iPhone 17, but each team member will have different simulator IDs for an iPhone 17 simulator, so I just added simulatorName: iPhone 17 to the config file.

However, every time I interact with XcodeBuildMCP thru Cursor, the simulatorId is added to the config file and I end up having changes that I have to discard in my branch.

Debug Output

XcodeBuildMCP Doctor

Generated: 2026-02-18T18:59:58.574Z
Server Version: 2.0.7

System Information

• platform: darwin
• release: 25.3.0
• arch: arm64
• cpus: 12 x Apple M3 Pro
• memory: 18 GB
• hostname: alegre-mbp.local
• username: jorge
• homedir: /Users/jorge
• tmpdir: /var/folders/qt/5lnnqrq159dgclfjxlg0sknc0000gn/T

Node.js Information

• version: v24.13.0
• execPath: /opt/homebrew/Cellar/xcodebuildmcp/2.0.7/libexec/node-runtime
• pid: 32923
• ppid: 32145
• platform: darwin
• arch: arm64
• cwd: /Users/jorge/Developer/Citizen/ios
• argv: /opt/homebrew/Cellar/xcodebuildmcp/2.0.7/libexec/node-runtime /opt/homebrew/Cellar/xcodebuildmcp/2.0.7/libexec/build/cli.js mcp

Process Tree

• Running under Xcode: ❌ No
• 32923 (ppid 32145): /opt/homebrew/Ce — /opt/homebrew/Cellar/xcodebuildmcp/2.0.7/libexec/node-runtime /opt/homebrew/Cellar/xcodebuildmcp/2.0.7/libexec/build/cli.js mcp
• 32145 (ppid 31563): Cursor — Helper (P Cursor Helper (Plugin): extension-host (user) [1-1]
• 31563 (ppid 1): /Applications/Cu — /Applications/Cursor.app/Contents/MacOS/Cursor
• 1 (ppid 0): /sbin/launchd — /sbin/launchd

Xcode Information

• version: Xcode 26.2 - Build version 17C52
• path: /Applications/Xcode-26.2.0.app/Contents/Developer
• selectedXcode: /Applications/Xcode-26.2.0.app/Contents/Developer/usr/bin/xcodebuild
• xcrunVersion: xcrun version 72.

Dependencies

• axe: ✅ v1.4.0
• xcodemake: ❌ Not found
• mise: ❌ Not found

Environment Variables

• INCREMENTAL_BUILDS_ENABLED: (not set)
• DEVELOPER_DIR: (not set)
• HOME: /Users/jorge
• USER: jorge
• TMPDIR: /var/folders/qt/5lnnqrq159dgclfjxlg0sknc0000gn/T/
• NODE_ENV: (not set)
• SENTRY_DISABLED: (not set)
• XCODEBUILDMCP_RESOURCE_ROOT: /opt/homebrew/Cellar/xcodebuildmcp/2.0.7/libexec
• XCODEBUILDMCP_RUNTIME: mcp
• XCODEBUILDMCP_SILENCE_LOGS: true

PATH

/Users/jorge/.local/bin
/Users/jorge/.antigravity/antigravity/bin
/Users/jorge/.pyenv/shims
/Users/jorge/.nvm/versions/node/v20.16.0/bin
/Users/jorge/google-cloud-sdk/bin
/Users/jorge/.mint/bin/
/Users/jorge/go/bin/
/opt/homebrew/bin
/usr/local/bin
/System/Cryptexes/App/usr/bin
/usr/bin
/bin
/usr/sbin
/sbin
/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin
/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin
/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin
/opt/pmk/env/global/bin
/Library/Apple/usr/bin
/Applications/Little Snitch.app/Contents/Components
/usr/local/go/bin
/opt/homebrew/opt/fzf/bin

Feature Status

UI Automation (axe)

• Available: ✅ Yes
• UI Automation Supported: ✅ Yes

Incremental Builds

• Enabled: ✅ Yes
• Available: ✅ Yes
• Makefile exists: ❌ No

Mise Integration

• Running under mise: ❌ No
• Mise available: ❌ No

Debugger Backend (DAP)

• lldb-dap available: ✅ Yes
• Selected backend: dap

Available Tools

• Total Plugins: 100
• Plugin Directories: 15
• debugging: 8 tools
• device: 14 tools
• doctor: 1 tools
• logging: 4 tools
• macos: 11 tools
• project-discovery: 5 tools
• project-scaffolding: 2 tools
• session-management: 4 tools
• simulator-management: 8 tools
• simulator: 21 tools
• swift-package: 6 tools
• ui-automation: 11 tools
• utilities: 1 tools
• workflow-discovery: 1 tools
• xcode-ide: 3 tools

Runtime Tool Registration

• Enabled Workflows: 8
• Registered Tools: 49
• Workflows: debugging, logging, project-discovery, session-management, simulator-management, simulator, ui-automation, utilities

Xcode IDE Bridge (mcpbridge)

• Workflow enabled: ❌ No
• mcpbridge path: (not found)
• Xcode running: true
• Connected: ❌ No
• Bridge PID: (none)
• Proxied tools: 0
• Last error: (none)
• Note: Bridge debug tools (status/sync/disconnect) are only registered when debug: true

Tool Availability Summary

• Build Tools: ✅ Available
• UI Automation Tools: ✅ Available
• Incremental Build Support: ✅ Available & Enabled

Sentry

• Sentry enabled: ✅ Yes

Troubleshooting Tips

• If UI automation tools are not available, install axe: brew tap cameroncooke/axe && brew install axe
• If incremental build support is not available, you can download the tool from https://github.com/cameroncooke/xcodemake. Make sure it's executable and available in your PATH
• To enable xcodemake, set environment variable: export INCREMENTAL_BUILDS_ENABLED=1
• For mise integration, follow instructions in the README.md file

Editor/Client

Cursor

MCP Server Version

2.0.7

LLM

Claude Opus 4.6

MCP Configuration

Steps to Reproduce

I asked the agent to build the app

Expected Behavior

Find the simulator ID without setting the ID in the .xcodebuildmcp/config.yaml file

Actual Behavior

It added a new line to the config with the simulator Id

Error Messages

[cameroncooke]

Thanks for raising this, this is very valuable feedback. You're right we convert simulator name to id, this is because some tools only work with simulator id, so we would need to do a lookup each time you do a tool call. Maybe we can add a configuration option to disable that behaviour and only do the name to id translation using an in-memory cache, would that work for you?

[cameroncooke]

One thing that's worth noting, while the simulatorId is captured in the config.yaml, it's auto-updated on MCP startup if simulatorName is set so while it will be an unstable identifier it shouldn't cause issues for users on other machines, it just creates commit noise which I accept.

[jorgealegre]

Hi @cameroncooke ! First off, thanks so much for building this great project, it's been phenomenal using it.

Yes, the approach you mention seems like a good fix for this :)

[jorgealegre]

thank you @cameroncooke !! 🙏