Runtime monitoring in Klaim through provably correct tuple-space checkpoints

We propose a runtime-monitoring mechanism for KLAIM that relies exclusively on its native tuple-space coordination primitives. The approach separates monitoring concerns from application logic: a reusable monitor process observes runtime events and maintains a control-state token in a dedicated tuple space, while checkpoint wrappers guard critical actions by inspecting that token through non-destructive reads, without ever modifying it. We prove that the pattern preserves a control-state invariant and that critical actions are admitted only after the clear state has been observed. A source-to-source translation turns ordinary KLAIM programs into checkpointed ones and is proved correct: translated executions project back to source executions, source behavior is preserved while the control state is clear, and every translated critical action is checkpoint-admitted. We broaden the basic pattern with several reusable variants, namely parameterized and multi-level monitors, history-dependent policies, local and global control, and event logging, that widen its applicability without changing its guarantees. We further identify safety-site preservation as the condition under which checkpointed mobile code continues to consult the intended monitor after migration. For the first-order, mobility-free fragment of KLAIM, we also show how a static tuple-trajectory analysis from the literature can drive checkpoint placement automatically: given a set of protected localities, it yields a conservative checkpoint-inference pipeline that, together with the translation and the runtime guarantee, covers every action that may interact with a protected resource. The whole approach is implemented in X-KLAIM and is illustrated through a self-contained cyber-physical case study involving a robotic arm with a multi-level safety protocol and emergency halting.