Hi there, I'm currently developing a Vapi assistant that is embedded on a doctor’s profile page from my app, allowing users to initiate a call via the Vapi SDK. In my setup, the assistant uses an MCP server through the Tools configuration. I need a way to identify the specific doctor when the AI assistant calls the MCP tools. While I know I can assign HTTP headers in the MCP configuration, those headers are static — but I need them to be dynamic based on the doctor whose page the user is calling from. Is there a way to dynamically set or pass a custom configuration (such as a header or other metadata) at the moment the call is initiated, so that when the assistant calls the MCP tools, it includes the doctor-specific information? This would allow my MCP server to return data tailored to the correct doctor. I’m trying this approach: const vapiInstance = new Vapi(import.meta.env.VITE_APP_VAPI_API_KEY); const assistantOverrides = { metadata: { doctorId: "abc123", }, }; vapiInstance.start(AppConfig.vapi.assistantId, assistantOverrides); And I would expect when the MCP is called to have access to this metadata. If there’s a better approach you recommend for this situation, I’m open to suggestions as well.

Yes, your approach works passing metadata like doctor Id via assistantOverrides lets your MCP server access it per call, enabling doctor-specific responses.