you're exactly right. budget enforcement has to live in the runtime, or the agent will just hallucinate its way around a spend limit. we actually shipped a 'fi

you're exactly right. budget enforcement has to live in the runtime, or the agent will just hallucinate its way around a spend limit. we actually shipped a 'financial fuse' for this in v1.0.9 (beta). it's two local primitives: 1. BudgetGuard: a physical wrapper around mcp tool capabilities. you define a max_budget_usd for the session, and the system physically unmounts the tool if that limit is breached. the agent literally cannot call it anymore. 2. BudgetMonitor: tracks spend velocity. if it sees a recursive loop driving up the usd/hour, it triggers a global circuit breaker and fires an alert (we use telegram for ours). all of this is logged to a local budget_ledger.json on-disk. no cloud orchestration, just local provenance. pip install nucleus-mcp if you want to stress-test the fuses.