Production Agent Design

Core Principle

The LLM is the reasoning engine. Your code is the execution engine. The loop is the contract between them.

Every production concern — safety, cost, retries, logging, permissions — lives in the harness, not the prompt. A prompt that says "be careful with deletions" is a suggestion. A GuardedToolNode that intercepts delete_* calls is a guarantee.

When to Use This Skill

• Designing a new multi-agent system from scratch
• Adding safety, cost controls, or observability to an existing agent
• Debugging runaway cost, infinite loops, or context window exhaustion
• Choosing between single-agent vs multi-agent topology
• Implementing human-in-the-loop (HITL) for irreversible actions
• Setting up session persistence and resumption

Architecture at a Glance