Hexis: a fixed 64-state structure for governing cognitive disposition in language-model agents — definitions, structural results and a pre-registered programme

When a language-model agent is authorised to act, choosing how to approach a situation becomes part of the task. A refund request, for example, may require a missing record, a policy check or a decision to defer before any action is appropriate. Hexis investigates whether these changes in approach can be represented explicitly, selected to suit the situation and tested for their contribution to better decisions. The proposed architecture pairs eight configurations of planning, monitoring and recall with eight descriptions of what the situation already supplies. This gives a sixty-four-state structure drawn from the I Ching, with defined relations between states and a project-defined boundary between deciding and executing. Its cognitive interpretation connects a fixed mathematical structure to questions from metacognition, control and practical-wisdom research: whether the configurations produce distinct behaviour, whether their selection improves decisions, and how timeliness and appropriateness should be assessed. A separate validation programme addresses that last question across systems. The paper presents reproducible structural checks, two proofs and a registered programme of behavioural and validity tests. The agent architecture and the proposed instrument remain to be built and tested. Yarrow is the planned open-source contribution through which others could reproduce the structure and evaluate the proposal.