It looks like you’re describing something like an MCP server and a client model.

If you’re in the C# ecosystem you could consider converting your APIs to MCP format tools using the MCP SDK.

https://devblogs.microsoft.com/dotnet/build-a-model-context-...

And then leveraging Microsoft Agent Framework for the client and orchestration side of things:

https://learn.microsoft.com/en-us/agent-framework/