r/AI_Agents: Deterministic LangGraph Harness Ships Where Critic Gate Is Structural Code, Not a Prompt — Removes LLM Non-Determinism From Evaluation Loop

Developer shares a LangGraph-based agent harness where the critic gate operates through structural checks rather than a prompt, eliminating the non-determinism problem inherent in LLM judges. The design separates evaluation logic from prompt space, making agent pass/fail decisions auditable and reproducible — a pattern the community has been groping toward as prompt-based critics repeatedly diverge across runs.