Prompt caching with dynamic context

export const chatAgent: Agent = new Agent({
  name: "chat-agent",
  tools: { }, // very large static toolset
  instructions: ({ runtimeContext }) => {
   // an example of some truly dynamic var, differs every req
   const currentTime = Date.now(); 
   
   return `${BASE_STATIC_SYSTEM_PROMPT} 

   - the user's name is ${runtimeContext.get('username')}
   - the current time is ${currentTime}`;
  },
});