Claude Agent SDK
Anthropic's first-party agent SDK for building production agents on top of Claude. Native MCP support, sub-agents, tool use, and prompt caching out of the box. Routinely benchmarked alongside Strands, LangGraph, and the OpenAI Agents SDK in 2026 framework comparisons.
OpenAI Agents SDK
OpenAI's production-grade agent framework, successor to Swarm. Core abstraction is explicit handoffs between agents carrying full context. Built for reliable multi-agent pipelines with native OpenAI tool use, tracing, and guardrails.