Model Routing / AI Gateway

Enterprise organizations quickly discover that running all AI traffic through a single premium model is both expensive and brittle. A sophisticated customer support ticket might require GPT-4o or Claude Sonnet for nuanced understanding, while a simple intent classification can be handled accurately by a much cheaper model — at one-tenth the cost. Meanwhile, depending on a single model provider creates availability risk: when OpenAI has an outage, every AI feature in your product goes dark simultaneously. Model routing and AI gateways address both problems.

An AI gateway is a reverse proxy for LLM APIs. It intercepts all model requests from your applications, applies routing logic, enforces policies, and forwards traffic to the appropriate model provider. The core routing strategies are: **complexity-based routing** (a lightweight classifier scores incoming queries and directs simple requests to smaller models, complex requests to larger ones); **cost-based routing** (always use the cheapest model that meets the quality threshold for a given task category); **fallback routing** (if the primary model provider returns an error or times out, automatically retry with a backup provider); and **A/B routing** (split traffic between model versions to evaluate quality differences in production). These strategies can be combined — a gateway might first check complexity, apply cost constraints, and maintain provider-specific fallback chains simultaneously.

The enterprise business case for an AI gateway compounds over time. Cost savings from complexity-based routing typically achieve 40-70% reduction in LLM spend without measurable quality degradation for production workloads with mixed task complexity. Centralized logging through the gateway creates an organization-wide audit trail of every LLM call — inputs, outputs, latency, cost, and model version — enabling both compliance reporting and per-team cost attribution. And the abstraction layer provides the organizational freedom to adopt new models as they emerge without refactoring every application.