AEF Wants to Do for Agent Lifecycles What OpenAPI Did for APIs

An independent developer has published an open specification that wants to do for AI agent lifecycles what OpenAPI did for REST APIs: give the ecosystem a shared vocabulary before the chaos becomes permanent.

The project, called AEF (Agent Execution Framework), models AI agents as finite state machines — defining structured conventions for how an agent initializes, executes, suspends, handles errors, and terminates. Its author, mikemasam, isn't building a runtime or an SDK. The spec is deliberately low-level, intended as the structural contract that frameworks and orchestration tools build against rather than replace.

The timing is pointed. LangGraph, AutoGen, CrewAI, and a growing list of competitors have all converged on graph or state-based execution models internally, but there's no common standard defining what an "agent state" actually is, how transitions should be triggered, or how lifecycle events get communicated across system boundaries. The result is an ecosystem of incompatible implementations where reasoning about agent behavior at scale means reading source code instead of consulting a spec.

AEF sits at a different layer than the interoperability efforts gaining traction elsewhere. Anthropic's Model Context Protocol handles tool and resource access. Google's Agent2Agent protocol targets communication between agents. OpenAI's Agents SDK provides an opinionated runtime. None of them define the internal execution lifecycle of a single agent — which is precisely the gap AEF is trying to fill.

There's a real obstacle ahead, though: modern LLM-driven agents aren't clean state machines. Probabilistic outputs and emergent behavior make the tidy transition boundaries of classical automata theory break down quickly in practice. AEF will need to either extend the spec to handle non-deterministic transitions honestly, or define clear limits on where the model applies. The history of developer tooling suggests that specs which acknowledge their own edges tend to get adopted; specs that paper over them tend to get forked into oblivion. For AEF, the ugly cases aren't an edge case — they're the whole job.