Azure Functions Durable Entities: Actor Model in Serverless

Durable Entities provide an actor-like model in Azure Functions. Each entity has an identity, state, and handles operations serially.

[FunctionName("Counter")]
public static void Counter([EntityTrigger] IDurableEntityContext ctx)
{
    switch (ctx.OperationName)
    {
        case "add":
            ctx.SetState(ctx.GetState<int>() + ctx.GetInput<int>());
            break;
        case "get":
            ctx.Return(ctx.GetState<int>());
            break;
    }
}

Call it from an orchestrator: ctx.SignalEntity(entityId, "add", 5);