LangChain Deep Agents vs OpenAI Agents SDK (2026)

If you're building AI agents in Python right now, two frameworks are competing for your attention: LangChain Deep Agents (launched March 15, 2026) and the OpenAI Agents SDK (early March 2026). Both promise production-ready multi-agent orchestration. Both have real traction -- Deep Agents hit 9.9k GitHub stars in 5 hours, while the Agents SDK formalized patterns thousands of teams were already hacking together with OpenAI's experimental Swarm library. But they solve the problem from fundamentally different directions. Deep Agents is an agent harness -- batteries-included with planning, filesystem context management, and subagent spawning baked in. The Agents SDK is a lightweight toolkit -- minimal primitives (agents, handoffs, guardrails) that you compose with Python. Picking the wrong one means rewriting your orchestration layer in three months. This comparison breaks down the architectures, shows code side-by-side, and gives you a decision framework so you can pick the right tool for