Tool overview
Semantic Router is listed under Programming AI tools.
What is Semantic Router?
Semantic Router is an MIT-licensed Python library that routes requests using semantic vector similarity instead of waiting for a generative model. It supports static and dynamic routes, local execution, multimodal encoders, vector databases, and multiple model providers.
Best for
Developers adding fast semantic routing and guardrails to LLM or agent applications
Who is it for?
Decision note
Rebuilt from the original export under the complete V411 factual-source-verification workflow. Preview only. Apply remains blocked until Failures = 0, Warnings = 0, Unmapped = 0, Missing = 0; explicit clears are reviewed; image import is disabled or V380 accepts the asset; a representative WordPress edit screen is compared with the export and proposed row; and a post-Apply zero-change Preview succeeds.
Key features
Fast semantic routing without full LLM generation
Static, dynamic, hybrid, and multimodal routes
Local encoders and external provider integrations
Pinecone, Qdrant, OpenAI, Cohere, and Hugging Face support
Use cases
Route requests to tools or models
Add deterministic guardrails
Reduce unnecessary model calls
Classify multimodal inputs
Pros
- MIT licensed and locally runnable
- Current package release is actively maintained
- Direct Python API and examples
Limitations
Poor route examples or thresholds can silently send requests to the wrong tool or model.
Teams must test fallback behavior, class imbalance, provider drift, latency, and sensitive-data handling.
Pricing details
Billing options
Pricing note
The Semantic Router library is free under MIT. Teams separately pay for external embedding or language-model APIs, vector databases, observability, hosting, and engineering operations.
Supported programming languages
- English
Integrations
OpenAI
Cohere
Hugging Face
Pinecone
Qdrant
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