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 (xcrun mcpbridge, available since Xcode 26.3) that exposes 20 IDE tools to external AI clients. Xcode 27 adds an explicit "Allow external agents to use Xcode tools" gate, the run-agent launch path, and an agent-extension model (custom MCP servers, skills, plug-ins). This skill suite covers setup, tool reference, workflow patterns, and troubleshooting.

When to Use

Use this skill when:

• Setting up Xcode MCP for the first time
• Configuring xcrun mcpbridge for any MCP client
• Using any Xcode MCP tool (file ops, build, test, preview)
• Building, testing, or previewing via MCP tools
• Troubleshooting mcpbridge connection issues
• Window/tab targeting questions
• Permission dialog confusion

Routing Logic

1. Setup/Connection → xcode-mcp-setup

Triggers:

• First-time Xcode MCP setup
• Client-specific config (Claude Code, Cursor, Codex, VS Code, Gemini CLI)
• Connection errors ("Connection refused", "No windows")
• Permission dialog confusion
• Multi-Xcode targeting (MCP_XCODE_PID)
• Schema compliance issues with strict clients
• Giving external agents access to Xcode (Intelligence settings gate)
• Launching an agent via Xcode config (xcrun mcpbridge run-agent)
• Exporting Xcode's skill bundles (run-agent skills export)
• Extending Xcode's agent (per-agent config files, MCP servers, plug-ins)

Read: skills/xcode-mcp-setup.md

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2. Using Tools & Workflows → xcode-mcp-tools

Triggers:

• How to build/test/preview via MCP
• Workflow patterns (BuildFix loop, TestFix loop)
• Tool gotchas and anti-patterns
• Window/tab targeting strategy
• When to use MCP tools vs CLI (xcodebuild)
• Destructive operation safety (XcodeRM, XcodeMV)

Read: skills/xcode-mcp-tools.md

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3. Tool API Reference → xcode-mcp-ref

Triggers:

• Specific tool parameters and schemas
• Input/output format for a tool
• "How does XcodeGrep work?"
• "What params does BuildProject take?"
• Tool category listing

Read: skills/xcode-mcp-ref.md

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Decision Tree

digraph xcode_mcp_router {
    rankdir=TB;
    "User has Xcode MCP question" [shape=ellipse];
    "Setup or connection?" [shape=diamond];
    "Using tools or workflows?" [shape=diamond];
    "Need specific tool params?" [shape=diamond];

    "xcode-mcp-setup" [shape=box];
    "xcode-mcp-tools" [shape=box];
    "xcode-mcp-ref" [shape=box];

    "User has Xcode MCP question" -> "Setup or connection?";
    "Setup or connection?" -> "xcode-mcp-setup" [label="yes"];
    "Setup or connection?" -> "Using tools or workflows?" [label="no"];
    "Using tools or workflows?" -> "xcode-mcp-tools" [label="yes"];
    "Using tools or workflows?" -> "Need specific tool params?" [label="no"];
    "Need specific tool params?" -> "xcode-mcp-ref" [label="yes"];
    "Need specific tool params?" -> "xcode-mcp-tools" [label="general question"];
}

Anti-Rationalization

| Thought | Reality | |---------|---------| | "I'll just use xcodebuild directly" | MCP gives IDE state, diagnostics, previews, and navigator issues that CLI doesn't expose | | "I already know how to set up MCP" | Client configs differ. Permission dialog behavior is specific. Check setup skill. | | "I can figure out the tool params" | Tool schemas have required fields and gotchas. Check ref skill. | | "Tab identifiers are obvious" | Most tools fail silently without correct tabIdentifier. Tools skill explains targeting. | | "This is just file reading, I'll use Read tool" | XcodeRead sees Xcode's project view including generated files and resolved packages |

Conflict Resolution (vs Other Routers)

| Domain | Owner | Why | |--------|-------|-----| | MCP-specific interaction (mcpbridge, MCP tools, tab identifiers) | xcode-mcp | MCP protocol and tool-specific | | Xcode environment (Derived Data, zombie processes, simulators) | axiom-build | Environment diagnostics, not MCP | | Apple's bundled documentation (for-LLM guides/diagnostics) | apple-docs | Bundled docs, not MCP tool | | DocumentationSearch MCP tool usage specifically | xcode-mcp | MCP tool invocation | | Build failures diagnosed via CLI | axiom-build | Traditional build debugging | | Build failures diagnosed via MCP tools | xcode-mcp | MCP workflow patterns |

Example Invocations

User: "How do I set up Xcode MCP with Claude Code?" -> Read: skills/xcode-mcp-setup.md

User: "How do I build my project using MCP tools?" -> Read: skills/xcode-mcp-tools.md

User: "What parameters does BuildProject take?" -> Read: skills/xcode-mcp-ref.md

User: "My mcpbridge connection keeps failing" -> Read: skills/xcode-mcp-setup.md

User: "How do I target a specific Xcode window?" -> Read: skills/xcode-mcp-tools.md

User: "Can I render SwiftUI previews via MCP?" -> Read: skills/xcode-mcp-tools.md (workflow), then skills/xcode-mcp-ref.md (params)

User: "Cursor can't parse Xcode's MCP responses" -> Read: skills/xcode-mcp-setup.md (schema compliance section)

Resources

References: skills/xcode-mcp-setup.md, skills/xcode-mcp-tools.md, skills/xcode-mcp-ref.md, skills/axe-ref.md

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: CharlesWiltgen
• Source: CharlesWiltgen/Axiom
• License: MIT
• Homepage: https://charleswiltgen.github.io/Axiom/

Install and usage instructions live in the source repository linked above.