BitRouter

BitRouter is an open-source LLM routing and optimization platform designed to reduce the cost and improve the performance of AI agent workflows. It operates as a configurable gateway that sits between AI agents and multiple upstream large language model (LLM) providers, dynamically selecting the most appropriate model for each call based on factors such as cost, task complexity, and provider health. The tool is intended for developers and teams building AI-powered applications who want to optimize their agentic loops without being locked into a single model or provider.

The platform traces each model call in the request path, attributing costs and providing full call-chain observability. It evaluates the requirements of every request, matching tasks to the cheapest model that maintains quality, and routes calls accordingly. BitRouter supports failover across providers mid-run, ensuring that interruptions or provider errors do not result in lost progress or redundant costs. The routing logic is adaptive, learning and optimizing continuously with each run, without requiring manual tuning or static rule maintenance. Users can override routing decisions per call if needed, maintaining flexibility.

0 license, allowing users to self-host by forking the binary or to opt into a hosted cloud version. Installation options include curl, npm, and brew, and the platform can be integrated into agent workflows without additional SDKs. It supports routing to both open and proprietary models, including providers such as Anthropic, OpenAI, DeepSeek, Qwen, MoonshotAI, and Minimax. The system is designed to avoid model, harness, or router lock-in, giving users the ability to swap between models and agent frameworks as needed.

Benchmark data referenced by BitRouter indicates that its adaptive routing can achieve significant cost reductions compared to static routing strategies, with one example showing a 33% decrease in cost at the same solve rate on a standard evaluation suite. The platform also includes features such as per-run cost attribution, prompt-injection guardrails, and a permissionless provider registry. BitRouter is positioned as an AI model router, offering a unified API layer for intelligent model selection and robust agent integration.