The original title is "AI Agent Stack in 2026: LangGraph vs Custom vs DIY"

Short summary

A practitioner's guide to choosing between three agent stack approaches in 2026: a DIY while-loop (~150 lines), a framework like LangGraph, or custom orchestration on durable executors. The decision hinges on step count, concurrency needs, and crash recovery requirements. For simple linear agents with fewer than five tools, DIY wins on debuggability and cost transparency; frameworks earn their overhead only with real branching or durable execution needs.

• •DIY loops win for simple agents (<5 tools, linear flow) — transparent tokens, IDE-debuggable, ~40% of author's shipped agents
• •LangGraph justified when workflows have 3+ meaningful branches or need durable execution across hours/days
• •Custom orchestration (Temporal, Inngest, Step Functions) for long-running, crash-resilient multi-agent systems

Generated with AI, which can make mistakes.