Pepper MCP Server for iOS Simulator Interaction and Debugging
Pepper is an MCP server that enables AI agents to directly interact with and debug iOS simulator applications in real time. It works by injecting a dynamic library (dylib) into the iOS simulator app process using the DYLD_INSERT_LIBRARIES environment variable.
Core Functionality
Under the hood, Pepper runs a WebSocket server inside the iOS app process. The MCP server connects to this WebSocket bridge and provides structured access to the application's internal state, allowing agents to understand what's happening rather than relying on screenshots or previews.
Specific Capabilities
- Read the screen content
- Tap buttons and scroll
- Inspect live Swift variables at runtime
- Check network traffic
- Toggle feature flags
- Run accessibility audits
- Access the full view hierarchy
- Examine runtime state and app internals
Practical Applications
The creator uses Pepper for multiple development tasks:
- PR validation
- Bug reproduction
- Building full features end-to-end
- Verifying agent-generated code in parallel development workflows
The repository itself is built by agents running in parallel, using Pepper to verify their own work as they go.
📖 Read the full source: r/ClaudeAI
👀 See Also
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Browser CLI: A Token-Efficient Browser Automation Tool for AI Coding Agents
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ClaudeOrb: Chrome Extension Monitors Claude API Usage in Real-Time
A developer built ClaudeOrb, a free Chrome extension that displays Claude session percentage, weekly limits, countdown timers, Claude Code costs, and 7-day spending trends. The tool was created using Claude Code after hitting rate limits without warning.