vLLM Semantic Router

vLLM Semantic Router is a programmable Mixture-of-Models router for heterogeneous LLM inference.

vLLM Semantic Router is a signal-driven decision routing framework for Mixture-of-Modality and heterogeneous LLM deployments. It enables enterprises to control cost, privacy, and policy by routing every task to its best-fit model. The system evaluates configured signals, applies recipe policies, and selects eligible models from configured pools. It supports open, closed, and hybrid model integrations including Claude, ChatGPT, Gemini, Mistral, DeepSeek, and GLM. Designed for developers and enterprise teams, it provides semantic routing, policy enforcement, guardrails, and observability features to optimize inference performance.

vLLM Semantic Router at a glance

Best for: Software engineer
Runs on: self-hosted, open source, API
Pricing: Free
Released: August 2025
Category: AI coding tool
Website: vllm-sr.ai

Key features

Programmable Mixture-of-Models routing
Signal-driven decision routing framework
Policy and guardrail evaluation
Embedded similarity prompt matching
Replay and routing metrics export
Hard constraints for regulated traffic
Selection algorithms and loopers

Use it for

Route queries to the right model based on task shape and risk
Evaluate PII and jailbreak policies before model dispatch
Balance quality, latency, cost, and load
Keep regulated traffic on approved paths

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