SEAR: Schema-Based Evaluation and Routing for LLM Gateways

TL;DR

SEAR introduces a schema-based system for evaluating and routing LLM responses in gateways, enabling accurate, interpretable, and cost-effective multi-model management.

Contribution

It presents an extensible relational schema and reasoning methods for structured evaluation signals, unifying response assessment and request routing in LLM gateways.

Findings

Achieves strong signal accuracy on human-labeled data

Supports practical routing decisions with cost reductions

Enables human-interpretable explanations for routing

Abstract

Evaluating production LLM responses and routing requests across providers in LLM gateways requires fine-grained quality signals and operationally grounded decisions. To address this gap, we present SEAR, a schema-based evaluation and routing system for multi-model, multi-provider LLM gateways. SEAR defines an extensible relational schema covering both LLM evaluation signals (context, intent, response characteristics, issue attribution, and quality scores) and gateway operational metrics (latency, cost, throughput), with cross-table consistency links across around one hundred typed, SQL-queryable columns. To populate the evaluation signals reliably, SEAR proposes self-contained signal instructions, in-schema reasoning, and multi-stage generation that produces database-ready structured outputs. Because signals are derived through LLM reasoning rather than shallow classifiers, SEAR captures complex request semantics, enables human-interpretable routing explanations, and unifies evaluation and routing in a single query layer. Across thousands of production sessions, SEAR achieves strong signal accuracy on human-labeled data and supports practical routing decisions, including large cost reductions with comparable quality.