Show HN: Muxer – open-source model multiplexer for Claude Code
Muxer is an open-source model multiplexer for Claude Code that routes typing tasks to cheaper tiers while keeping the top model in control, with quality-preserving routing rules and cost savings printed after each task.
Background
- Claude Code is Anthropic's official command-line coding agent. It uses Claude's most capable (and most expensive) model to write, edit, and debug code autonomously.
- Muxer is a free/open-source wrapper that sits between the user and Claude Code. It intercepts requests and routes "thinking" (planning, architecture) to the premium model, but automatically switches to cheaper/faster models (e.g., Claude Haiku, GPT-4o-mini) for mechanical typing tasks like filling in boilerplate or writing repetitive code.
- The tool prints the dollar amount saved on each task, giving users a visible cost incentive. Its pitch: you keep the top model's reasoning quality while drastically reducing API spend.
- This matters because heavy users of coding agents can burn through hundreds of dollars a month in API costs. Muxer is part of a growing ecosystem of optimization tools that treat AI models as fungible resources, routing subtasks to the cheapest tier that can handle them.