CrewAI

The agent-framework market consolidated into four orchestration patterns, but those patterns leak into each other by the vendors' own docs. They are primitives on a spectrum from deterministic to autonomous, and the decision is which primitive you need, not which framework.

Andrew Ng's 2024 numbers made the empirical case that workflows beat models. By 2026 the missing layer is no longer the framework but the runtime: durable execution and durable memory. A single prompt has no state to lose; an agent does.