gRPC Remote Procedure Calls

gRPCAdvanced

Google's open-source RPC framework, letting programs on different machines call each other like local functions.

gRPC is Google's open-source RPC (remote procedure call) framework, now hosted by the Cloud Native Computing Foundation (CNCF). It defines interfaces and messages with Protobuf (a binary serialization format), runs over HTTP/2, supports bidirectional streaming, and can automatically generate client and server code in C++, Python, Go, and many other languages. In embodied AI, it's commonly used to connect “the GPU server running the model” to “the robot itself”: the robot sends images and joint state to a policy server and gets an action back, which saves the trouble of hand-rolling a socket protocol and makes cross-language use easy. It isn't a real-time control bus, though — millisecond-scale low-level motor loops are still left to something like EtherCAT or CAN.

ExampleBoston Dynamics' official Spot SDK exposes a gRPC-based interface, letting Python code send commands and read state remotely.

Also called: gRPC
Related: Protocol Buffers · Policy Server (Remote Inference) · WebSocket · ZeroMQ · Middleware
Sources: Introduction to gRPC