MCP goes stateless, OpenAI goes stateful: two opposite paths

两条相反的路：MCP 去状态，OpenAI 加状态

MCP's July 28, 2026 release candidate removes session IDs and goes stateless—each request carries all its own context, any server instance can handle it, and gateways route without deep inspection. This fixes real production failures where load-balanced stateful servers returned 404s. OpenAI moved the opposite way: since March 2025, the Responses API keeps reasoning state, conversation history, and hosted tools server-side. Community benchmarks show it's 2–3x slower than Chat Completions with no token savings; Hugging Face argues agent loops belong in the agent system, not the vendor. The split comes down to incentives: MCP is an open standard optimizing for interoperability, OpenAI is a vendor optimizing for lock-in.

Why it matters: MCP going stateless vs OpenAI going stateful is the clearest infrastructure-level divergence in Agent tooling as of July 2026. The piece has a reproduced failure, a timeline, and engineering judgment — not just opinion. Score capped below 85 because it's a single-source analys...