This Rust codebase is an LLM inference proxy and tool-routing gateway. It exposes an OpenAI-compatible HTTP API (`/v1/chat/completions`, `/v1/models`) and forwards requests to multiple upstream LLM providers (OpenAI, Anthropic via direct/Bedrock, Vertex AI, vLLM DeepSeek, TokenHub) through a unified Provider trait. A QUIC server (s2n-quic, TLS 1.3) accepts connections from serverless tools written in Go or Node.js; the agent loop performs multi-round tool calling, invokes registered tools, and streams results back in SSE format. A separate model API proxy layer handles non-chat endpoint shapes (messages, responses, generateContent) with usage extraction and injection. Architecturally, the system is a Rust CLI binary (`yomo`) with three subcommands: `serve` starts the HTTP API and QUIC zipper, `init` scaffolds serverless tool projects, and `run` launches a tool subprocess and connects it to the zipper. Tool registration is done at runtime over QUIC and stored in-memory, so state is lost on restart. The HTTP layer is Axum, auth is bearer-token, and observability uses OpenTelemetry. The serverless execution model is subprocess-based: it creates temporary directories, runs `npm install`/`go mod tidy`, and exchanges metadata over stdout. Reusable engineering exists in the framing protocol (`io`), streaming SSE mappers, usage aggregation logic, TLS configuration, and provider error separation. However, the provider implementations are duplicated and brittle to upstream API drift; hard-coded model limits, ephemeral tool state, and near-empty serverless stubs reduce long-term maintainability. No integration tests against real upstream APIs were found in the reviewed surface.