SentinelMCP

SentinelMCP is a free, open-source stateless gateway that acts as a policy firewall and token-cost proxy for Model Context Protocol servers. It enforces origin validation, identity verification, policy rules, and sliding-window token budgets to prevent runaway calls and unauthorized access to connected tools, with optional human approval for budget breaches. It supports Streamable HTTP and legacy HTTP+SSE protocols and is designed for security and cost control in enterprise LLM agent deployments.