Tool Brokers/Gateways

I'm looking to enhance security of AI agents by limiting their access to APIs. In my setup, the agent is secured in a sandbox and egress controls exist along with credential proxy injecting real credentials. Current sandbox setup: Agent -- calls --> deterministic script Script -- uses fake credentials to call --> API Proxy Proxy -- injects real credentials and calls --> API The problem: Agent can write a script that uses the API in unpredictable ways. The solution: Agent -- uses fake credentials to call --> Tool Gateway Proxy Proxy -- injects real credentials and calls --> Tool Gateway Tool Gateway -- authorizes tool use and executes --> deterministic script (tool) Script -- calls --> API I did a quick search and found Docker MCP Gateway that solves the same problem in a similar way, but it is geared for MCPs, so it is not exactly a perfect fit. Does anyone know a product/library that provides Tool Gateway functionality described above?