The AL0-AL4 framework is organized around one axis: who verifies the output and at what granularity. AL1 = human validates every output, AL2 = human certifies/validates AI output, AL3 = human performs auditing, sampling, and quality control, AL4 = no human. The level is a property of the workflow's verification topology, not of the model's capability.
Gives engineers a capability-independent way to classify and design agent workflows: instead of asking 'is the model good enough', ask 'where in the pipeline does verification live and at what sampling rate'. That reframes autonomy as an oversight-architecture decision, which is directly implementable as different runtime topologies (inline gate vs. out-of-band auditor).
Any agentic system operating under audit or safety constraints can be positioned on a verifier-granularity axis (per-output gate -> certification -> statistical sampling -> none), independent of the underlying model's raw capability.
AL1: Combination of human and AI assistance where human verifies and validates every output.
AL2: Majority of work done by AI, with human validating outputs and acting as verifier/certifier.
AL3: AI does the bulk of work while humans perform auditing, sampling, and quality control.
AL4: Fully autonomous AI agents executing tasks independently.