Router

Router (Weave Router) is a model-routing proxy for coding agents and other LLM applications. Clients such as Claude Code, Codex, OpenCode, and Cursor point at it instead of a provider, and it chooses a model from the enabled providers for every upstream API request, which it calls an action rather than a turn. The aim is to send each action to the cheapest model that meets the quality bar and keep frontier models for the requests that need them.

Routing uses a cluster scorer derived from the Avengers-Pro research method, running an in-process ONNX embedder on the router host rather than asking an LLM to classify the prompt. An optional frozen HMM policy can run as a companion container. The router speaks Anthropic Messages, OpenAI Chat Completions, and the native Gemini API, including streaming, tools, and vision, and reaches open models such as DeepSeek, Kimi, GLM, Qwen, Llama, and Mistral through OpenRouter or any OpenAI-compatible endpoint. A route endpoint returns the routing decision without calling a provider.

It runs as a hosted service or self-hosted with Postgres and a dashboard. Provider keys are bring-your-own, encrypted at rest, and prompts go from the router straight to the configured provider. An installer wires Claude Code, Codex, OpenCode, and pi to the router, adds commands to force or release a specific model, switch routing on or off, and choose which models the router may pick, and leaves the rest of each client's configuration untouched.

Every routed response reports its cost and cache-token usage, a per-session endpoint returns committed cost and savings, and raw routing decisions export as paginated NDJSON for analysis. OpenTelemetry traces go to the built-in dashboard or to collectors such as Honeycomb, Datadog, and Grafana.