AI state diagram generator from text

State diagrams are the right tool when what matters is the object's current condition and which transitions are legal from here, not the sequence in which things happen. Reach for them when you have a thing (an order, a document, a user account, a feature flag, a subscription) that moves through named states with clear rules about which state can follow which. The classic tell you need a state diagram: your team keeps arguing "wait, can a user be both suspended and pending-verification at the same time?" That's a question about state legality, not process order. A state diagram forces you to enumerate every state exactly once and every transition explicitly — which surfaces contradictions you'd otherwise ship as bugs. Mermaid's stateDiagram-v2 syntax supports composite states, concurrent regions, entry/exit actions, and the standard `[*]` start/terminal marker. Use it for order/subscription/document workflows, machine or IoT device modes, feature flag rollout phases, or any lifecycle that a compliance auditor might ask you to prove is bounded. Where state diagrams struggle: when interactions between multiple stateful objects dominate — then a sequence diagram on top helps.