Reason-act-observe

Interleave reasoning and action through a parseable protocol. Every executed action must have an attributable observation or an execution error; unparsed output is not an action.

def reason_act(task, model, tools):
    trace = []
    while not trace or trace[-1].kind != "final":
        raw = model.complete(task, trace)
        step = protocol.parse(raw)
        if step.kind == "action":
            try:
                observation = tools.execute(step.action)
            except ToolError as error:
                observation = Observation.error(step.action, error)
            trace.append(observation)
        else:
            trace.append(step)
    return trace