The deployment of autonomous AI agents in safety-critical enterprise workflows — medical diagnosis support, financial reconciliation, industrial control, regulatory filing — demands guarantees that transcend statistical performance metrics. Unlike a chatbot that can produce a plausible but incorrect answer with negligible real-world consequence, an agent that autonomously executes financial transactions or modifies patient records must satisfy formal properties: it must never perform action X, it must always perform action Y within T time steps, and it must never enter a state Z from which recovery is impossible.

We present a formal verification framework for AI agent behavior that combines static analysis (model checking), dynamic enforcement (runtime monitoring), and deductive verification (theorem proving). The framework has been applied to three production agent systems in regulated industries.

The Agent as a Transition System

We model a deterministic AI agent as a finite-state transition system M = (S, s0, A, T, L), where S is a finite set of states (abstracted from the LLM's continuous latent space via predicate abstraction), s0 is the initial state, A is the set of tool-call actions, T: S à A → S is the transition function, and L: S → 2AP labels each state with atomic propositions that hold in that state. The agent's policy π: S → A is the LLM's action-selection function.

Verification asks: does M ⊧ φ for a temporal logic formula φ? Safety properties (something bad never happens) are expressed in Linear Temporal Logic as G¬(bad), where G is the "globally" operator. Liveness properties (something good eventually happens) are expressed as F(good).

Key Challenge: The state space of a real agent is infinite due to the LLM's latent representation. We construct a finite abstraction using program analysis on the agent's code and tool schema, bounding the state space to approximately 106-108 abstract states — within reach of modern symbolic model checkers (e.g., nuXmv, CBMC) when optimized with binary decision diagrams.

Three Verification Approaches