public sealed class Function : ALambdaScheduleFunction {

    //--- Methods ---
    public override async Task InitializeAsync(LambdaConfig config) { }

    public override async Task ProcessEventAsync(LambdaScheduleEvent schedule) {
        var response = await HttpClient.GetAsync("https://api.coindesk.com/v1/bpi/currentprice.json");
        if(response.IsSuccessStatusCode) {
            LogInfo("Fetched price from API");

            // read price from API response
            dynamic json = JObject.Parse(await response.Content.ReadAsStringAsync());
            var price = (double)json.bpi.USD.rate_float;

            // log and send CloudWatch event
            LogEvent(new BitcoinPriceEvent {
                Price = price
            });
        } else {
            LogInfo("Unable to fetch price");
        }
    }
}

@code {

    //--- Fields ---
    private Dictionary<string, bool> _votes = new Dictionary<string, bool>();

    //--- Properties ---
    protected string BitcoinPrice { get; set; } = "(waiting for price)"
    protected bool IsDisabled { get; set; } = true;
    protected int UpVotes { get; set; }
    protected int DownVotes { get; set; }

    protected void OnUpVoteClicked() {
        LogInfo("Up vote!");

        // log and send CloudWatch event
        LogEvent(new BitcoinVoteEvent {
            VoterId = Info.AppInstanceId,
            Vote = true
        });
    }

    protected void OnDownVoteClicked() {
        LogInfo("Down vote!");

        // log and send CloudWatch event
        LogEvent(new BitcoinVoteEvent {
            VoterId = Info.AppInstanceId,
            Vote = false
        });
    }
}

protected override void OnInitialized() {
    base.OnInitialized();

    // subscribe to events from the Lambda function
    EventBus.SubscribeTo<BitcoinPriceEvent>(
        "Bitcoin.HotOrNot::PublishBitcoinPriceFunction",
        OnBitcoinPrice
    );

    // subscribe to events from other app instances
    EventBus.SubscribeTo<BitcoinVoteEvent>(
        "Bitcoin.HotOrNot::VoteApp",
        OnBitcoinVote
    );
}

protected void OnBitcoinPrice(BitcoinPriceEvent priceEvent) {

    // update price information
    BitcoinPrice = priceEvent.Price.ToString("C2");

    // enable voting buttons
    IsDisabled = false;

    // refresh UI state
    StateHasChanged();
}

protected void OnBitcoinVote(BitcoinVoteEvent voteEvent) {

    // register vote by voter ID
    _votes[voteEvent.VoterId] = voteEvent.Vote;

    // count up/down votes
    UpVotes = _votes.Values.Count(vote => vote);
    DownVotes = _votes.Values.Count(vote => !vote);

    // refresh UI state
    StateHasChanged();
}