This application relates to a communication method, an apparatus, and a system. A computing node obtains code of a first function based on a session establishment request of a terminal device, where the session establishment request is used to request to establish a first session. After obtaining the code of the first function, the computing node receives, from the terminal device via the first session, a first request used to access the first function, and runs the code of the first function based on first indication information, to process the first request. In embodiments of this application, the computing node may first obtain the code of the first function before receiving the first request from the terminal device, so that after receiving the first request, the computing node does not need to perform a code download process.