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Semantic-router

As explained in Natural Language Processing in Action, Second Edition

A semantic router is a routing component that predicts the most appropriate model or processing destination for an input based on its meaning.

A semantic router reads a prompt, predicts which language model best fits the request, then sends the request to that model and processes its output. This makes a collection of smaller or specialized models act as one system. section 10.1.2

A practical routing workflow can:

  • Break a prompt into the steps required for the task. section 10.1.2
  • Generate API queries that reach into external systems when the task requires them. section 10.1.2
  • Choose an appropriate LLM or downstream processing path from the prompt's meaning. section 10.1.2
  • Use natural-language classification to distinguish, for example, knowledge-base questions from other queries. section 10.1.3

Routing a chatbot request

A chatbot can classify an incoming request as a question and send it to its knowledge base, while routing other requests elsewhere. A few training examples can support generalization, potentially reducing engineering and compute costs compared with sending every request through a larger intermediary model. section 10.1.3

How Natural Language Processing in Action, Second Edition covers it

How deep it goes
Defines the routing idea and its workflow, but stops short of implementation code or routing evaluation procedures.
Examples
Uses prompt decomposition, API queries, and a chatbot classifier that separates knowledge-base questions from other queries.
What it assumes
Assumes familiarity with prompts, LLMs, APIs, and chatbots, while defining semantic routing and classification in plain language.
What you can do after
Operate multi-model applications by selecting suitable LLMs or processing routes for different natural-language requests.
How it connects
Connects semantic routing with natural language classification, LLMs, API queries, chatbots, knowledge bases, and guardrails.

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Natural Language Processing in Action, Second Edition. The section links point to the parts of the book it draws on.