gRPC Remote Procedure Call
gRPC is the dominant service-to-service RPC in polyglot microservices. Smaller payloads and faster than JSON/REST for high-throughput internal APIs.
What It Defines
gRPC is an RPC framework using Protocol Buffers (protobuf) as the IDL and wire format, with HTTP/2 as transport. Features: bidirectional streaming, strong typing, language-agnostic code generation, and low payload size.
Canonical (Normative)
Convenient (Practical)
Related References
gRPC is an open-source RPC framework originally developed at Google. It uses Protocol Buffers (protobuf) as its IDL and wire format, and HTTP/2 as the transport. Now a CNCF graduated project.
Related Specs
This is the core contract of every web API, browser request, and server response. You can't design or debug HTTP without knowing this.
OpenAPI is the de-facto standard for API documentation, code generation, mock servers, and contract testing. Most APIs you build should have an OpenAPI spec.
Protobuf is the wire format for gRPC and many high-performance internal APIs. Schemas are also used for event/message contracts in Kafka/pubsub systems.