typemux-cc

Python type-checker LSP multiplexer for Claude Code that auto-detects .venv and routes to pyright/ty/pyrefly without requiring restarts

typemux-cc

Python type-checker LSP multiplexer for Claude Code — auto-detects .venv changes and routes to pyright, ty, or pyrefly without restarts

Problems Solved

Claude Code’s official pyright plugin spawns a single LSP backend at startup and holds onto it. If .venv doesn’t exist yet — or you create a new one later — it never picks it up. You have to restart Claude Code.

This is especially painful with git worktrees, now common in AI-assisted development: you spin up a fresh worktree, create .venv, and then must restart Claude Code just to get type-checking.

typemux-cc fixes this — .venv changes are reflected within your running session, no restarts required.

Late .venv Creation

Spin up a git worktree, create .venv later, and typemux-cc picks it up on the next file open. No Claude Code restart needed.

Multi-Project Switching

Keeps a per-.venv backend pool and routes requests to the correct one. Switching between projects in monorepos is instant.

Multi-Backend Support

Not locked into pyright. Choose between pyright, ty, or pyrefly — switch via a single env var.

Supported Backends

Backend	Command	Status
pyright	pyright-langserver --stdio	✅ Stable (default)
ty	ty server	🧪 Experimental (verified)
pyrefly	pyrefly lsp	🧪 Experimental (verified)

Quick Start

1. Install a backend

   Install your preferred LSP backend (pyright recommended):

   npm

   npm install -g pyright
   
2. Disable official pyright plugin

   You must disable the official pyright plugin to avoid conflicts:

   /plugin disable pyright-lsp@claude-plugins-official
   
3. Install typemux-cc

   Add the marketplace and install the plugin:

   /plugin marketplace add K-dash/typemux-cc
   /plugin install typemux-cc@typemux-cc-marketplace
   
4. Restart Claude Code

   Restart Claude Code to activate the plugin. This is only required for initial installation — after this, .venv creation and switching no longer require restarts.

Key Features

Auto-detect .venv changes

No Claude Code restart needed when creating or switching virtual environments

Multi-backend support

Choose between pyright, ty, or pyrefly with a single environment variable

Git worktree support

Create .venv after opening a worktree — typemux-cc picks it up automatically

Monorepo switching

Instant switching between projects with different .venv paths

LRU backend pool

Maintains multiple backend processes with automatic eviction when idle

Warmup readiness

Queues index-dependent requests until backend finishes building its index

Why LSP over Text Search?

In monorepos, grep returns false positives from same-named types across projects. LSP resolves references at the type-system level, providing accurate cross-file navigation and refactoring.

See the architecture documentation for detailed design philosophy and implementation details.

Next Steps

Installation Guide

Detailed installation instructions for all platforms

Configuration

Configure backends, logging, and pool settings

Troubleshooting

Fix common issues and learn debugging techniques

Architecture

Understand how typemux-cc works under the hood