# gRPC

gRPC - GRPC Remote Procedure Call. The "G" could also just stand for "Google" which is one of the main drive forces behind the protocol. It's a high performance, open-source universal RPC framework. gRPC uses Protocol Buffers v3.


  • high serialization/deserialization performance (especially deserialization when compared to JSON)
  • wide adoption in programming languages
  • binary communication (no JSON, XML, whatever) - small size
  • contract-based
  • requires HTTP/2 (HTTPS by default)
  • uni- and bi-directional streaming
  • great for low-power devices (IoT)


  • backend-to-backend communication, e.g. between microservices

Usage on the frontend is not as straightforward as with REST.

# Contracts

The Server and the Client are generated using the ProtoBuf.

# ProtoBuf

Protocol Buffers (ProtoBuf) is a language for defining interfaces.

  • language/platform neutral
  • extensible
  • serializable
  • not specific to gRPC

It comes with its own set of types for defining data.

# Example


1: 100
2: "Hello There"


1: 94.5
2: 15.4
3: .5

# Streaming

Thanks to HTTP/2 base, gRPC supports streaming. It's very similar to how websockets work. The streaming works in any direction (client -> server or server -> client), it can also be both ways at the same time.

To support streaming, the protobuf file needs to explicitly contain such information attached to the input of the chosen rpc.

# Usage

# .NET

Read here.

# gRPC-Web

gRPC-Web is the way to call gRPC servers from the frontend layer (from JS). ASP.NET Core supports it via an additional NuGet package.

# Tools

# References

Pluralsight (opens new window) A nice intro to protobuf (opens new window)

Last Updated: 11/28/2022, 9:27:43 AM