Which integrations are available for this server?

Enables execution of Python code with pexpect functionality for interactive process control and debugging sessions with command-line tools like LLDB and GDB

How do I use Pexpect MCP Server?

1. Click on "Install Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@Pexpect MCP Server debug the demo-buggy program with lldb and show me the backtrace" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

pexpect-mcp

An MCP (Model Context Protocol) server that provides remote pexpect session control for debugging and process interaction.

Overview

This MCP server enables AI assistants to execute Python code with pexpect functionality, allowing for interactive debugging sessions with tools like LLDB, GDB, and other command-line utilities that require programmatic interaction.

In some sense this is less of a pexpect MCP as one that is just maintaining a stateful Python session.

Related MCP server: Python MCP Sandbox

Installation

uv tool install git+https://github.com/mitsuhiko/pexpect-mcp

Usage

As an MCP Server

Add to your Claude Code configuration:

{ "mcpServers": { "pexpect": { "command": "pexpect-mcp" } } }

Tool Usage

The server provides a single tool: pexpect_tool

Parameters:

code (string): Python code to execute with pexpect support
timeout (optional int): Timeout in seconds (default: 30)

Example Usage:

# Start a debugging session child = pexpect.spawn('lldb ./my-program') child.expect('(lldb)') # Run the program child.sendline('run') child.expect('(lldb)') print(child.before.decode()) # Get backtrace child.sendline('bt') child.expect('(lldb)') print(child.before.decode())

Demo

The repository includes a demo with a buggy C program (demo-buggy.c) that can be debugged using LLDB through the pexpect interface. This demonstrates the server's capability for interactive debugging sessions.

The program `./demo-buggy` crashes when executed. Use LLDB to: - Start the program under the debugger - Identify where and why it crashes - Examine variables, memory, and call stack - Report the root cause of the crash