lookin-mcp-ios

MCP Server for iOS UI inspection — lets any AI agent (Claude Code, Cursor, Codex, etc.) inspect live iOS app UI hierarchy, attributes, and screenshots via LookinServer, no Lookin.app required.

Prerequisites

• iOS App integrated with LookinServerMCP, running on simulator or device
• Node.js 18+

iOS Integration

Add the following to your Podfile:

pod 'LookinServerMCP', :configurations => ['Debug']

Only included in Debug builds — safe to leave in your Podfile permanently.

How It Works

AI Agent (Claude Code / Cursor / Codex / ...)
    ↓ stdio (MCP protocol)
lookin-mcp-ios (Node.js)
    ↓ HTTP local port
LookinServer (embedded in iOS App)

The MCP Server communicates directly with LookinServer embedded in your iOS app over local HTTP, no Lookin.app relay needed.

Installation

Claude Code

claude mcp add --scope user lookin -- npx -y lookin-mcp-ios

Cursor

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json in your project root:

{
  "mcpServers": {
    "lookin": {
      "command": "npx",
      "args": ["-y", "lookin-mcp-ios"]
    }
  }
}

Codex

Add to ~/.codex/config.yaml:

mcp_servers:
  - name: lookin
    command: npx
    args:
      - -y
      - lookin-mcp-ios

Tools

lookin_get_hierarchy

Returns the full UI view hierarchy tree of the running iOS app.

Parameters:

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | includeSystemViews | boolean | No | Reserved parameter, no filtering effect when connected directly to LookinServer | | maxDepth | number | No | Maximum hierarchy depth. Returns all levels if omitted |

Example response:

{"appName":"Demo","totalViews":12,"hierarchy":[{"oid":4393842688,"className":"UIWindow","frame":[0,0,390,844],"children":[{"oid":4393842944,"className":"MyViewController","frame":[0,0,390,844],"children":[]}]}]}

Node fields:

• oid — unique view identifier, used as input for other tools
• className — class name
• frame — position and size [x, y, width, height]
• hidden — only present when true
• alpha — only present when not 1.0

lookin_get_attributes

Returns all UI attributes of a specified view.

Parameters:

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | oid | number | Yes | View ID (from lookin_get_hierarchy) |

Response: Attributes grouped by group → section → attribute, each containing:

• identifier — attribute identifier
• setterSelector — setter method name, e.g. setBackgroundColor:
• attrType — value type enum
• value — current value

attrType values:

| Value | Type | |-------|------| | 14 | BOOL | | 12 | float | | 13 | double | | 5 | NSInteger | | 20 | CGRect | | 17 | CGPoint | | 19 | CGSize | | 22 | UIEdgeInsets | | 23 | UIColor (RGBA array, 0~1) | | 25 | enum int | | 26 | enum long | | 24 | NSString |

lookin_get_screenshot

Captures a screenshot of a specified view from the live iOS app rendering.

Parameters:

| Parameter | Type | Required | Description | |-----------|------|----------|-------------| | oid | number | No | View ID. If omitted, automatically uses the root window for a full-screen screenshot |

Response: MCP image content in PNG format, viewable directly by the AI agent.

Typical Workflow

1. lookin_get_hierarchy          → get the view tree and find the target view's oid
2. lookin_get_attributes(oid)    → inspect all attributes of that view
3. lookin_get_screenshot(oid)    → capture a screenshot to see the current UI state