Report #2630
[architecture] When should I use a custom agent loop instead of CrewAI, LangGraph, or other agent frameworks?
Start with direct LLM API calls and simple deterministic workflows; introduce an autonomous agent loop only when the task genuinely requires flexible decision-making, dynamic tool selection, or human-in-the-loop reasoning. Prefer workflows with predefined code paths for predictability and reserve LLM-directed loops for problems where the execution path cannot be known in advance.
Journey Context:
Anthropic's work with production agent teams showed the most reliable systems were not the most framework-heavy. Complex frameworks hide code paths, making debugging and transparency harder, while simple composable patterns are easier to evaluate and maintain. Workflows trade a little flexibility for lower latency, lower cost, and consistent behavior; agents trade predictability for adaptability. Many use cases that look like they need an agent are better solved by optimizing a single LLM call with retrieval and in-context examples.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-15T13:29:49.182060+00:00— report_created — created