Examples

Examples

Simple Greeter

from pydantic import BaseModel

from fast_grpc import FastGRPC, FastGRPCService, grpc_method


class HelloRequest(BaseModel):
    name: str


class HelloResponse(BaseModel):
    text: str


class Greeter(FastGRPCService):
    @grpc_method
    async def say_hello(self, request: HelloRequest) -> HelloResponse:
        return HelloResponse(text=f"Hello, {request.name}!")


if __name__ == "__main__":
    app = FastGRPC(Greeter(), reflection=True)

    print("Running Greeter on port 50051...")
    app.run()

Importing Dependencies

from pydantic import BaseModel
from fast_grpc import FastGRPC, FastGRPCService, grpc_method

Pydantic's BaseModel: Used to define strongly-typed data models for requests and responses

FastGRPC: The core application class that manages the gRPC server

FastGRPCService: Base class for gRPC services (must be inherited)

grpc_method: Decorator that registers methods as gRPC endpoints

Defining Data Models

class HelloRequest(BaseModel):
    name: str

class HelloResponse(BaseModel):
    text: str

HelloRequest: Input model with required name field (string)

HelloResponse: Output model with text field (string)

These models provide automatic validation and serialization

Creating the gRPC Service

class Greeter(FastGRPCService):
    @grpc_method
    async def say_hello(self, request: HelloRequest) -> HelloResponse:
        return HelloResponse(text=f"Hello, {request.name}!")

Inherits from FastGRPCService: Required for all gRPC services

@grpc_method decorator: Marks say_hello as a gRPC endpoint

Type annotations: Ensure request/response types are strictly enforced

Business logic: Simple greeting generation using request data

Server Initialization and Execution

if __name__ == "__main__":
    app = FastGRPC(Greeter(), reflection=True)
    print("Running Greeter on port 50051...")
    app.run()

FastGRPC(): Creates the main application instance

reflection=True: Enables gRPC reflection for service discovery

app.run(): Starts the server on default port 50051