Receive SMS

C#

// Receive inbound SMS and delivery receipts by webhook (ASP.NET Core minimal API, .NET 8 or later)
using System.Security.Cryptography;
using System.Text;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

// A long random token in the URL stops anyone else posting to your endpoints.
var token = Encoding.UTF8.GetBytes(app.Configuration["EmWebhookToken"]
            ?? throw new InvalidOperationException("Set EmWebhookToken"));
bool Valid(string key) => CryptographicOperations.FixedTimeEquals(Encoding.UTF8.GetBytes(key), token);

app.MapPost("/everymessage/inbound/{key}", (string key, CallbackBatch<InboundMessage> batch,
    ILogger<Program> log) =>
{
    if (!Valid(key)) return Results.NotFound();

    foreach (var m in batch.List)
        log.LogInformation("SMS {Id} from {Sender} to {Inbox}: {Content}",
            m.MessageId, m.Sender, m.InboxNumber, m.Content);

    // Any 2xx response tells everymessage the batch was received.
    return Results.Ok(new { echo = "ACK" });
});

app.MapPost("/everymessage/receipts/{key}", (string key, CallbackBatch<DeliveryReceipt> batch,
    ILogger<Program> log) =>
{
    if (!Valid(key)) return Results.NotFound();

    foreach (var r in batch.List)
        log.LogInformation("Message {Id} ({Reference}) to {Recipient}: {Status}",
            r.MessageId, r.Reference, r.Recipient, r.Status);

    return Results.Ok(new { echo = "ACK" });
});

app.Run();

record CallbackBatch<T>(IReadOnlyList<T> List);
record InboundMessage(string Type, long MessageId, string Sender, string? InboxName,
    string? InboxNumber, string? InboxKeyword, string Content, DateTimeOffset DateTime);
record DeliveryReceipt(string Type, long MessageId, string? Reference, string Recipient,
    string Status, DateTimeOffset DateTime);

C#

// Collect inbound SMS replies with the everymessage v1 API (.NET 8 or later)
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text;

var apiKey = Environment.GetEnvironmentVariable("EM_API_KEY")!;
var secretKey = Environment.GetEnvironmentVariable("EM_SECRET_KEY")!;

using var http = new HttpClient { BaseAddress = new Uri("https://api.everymessage.com/") };
http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(
    "Basic", Convert.ToBase64String(Encoding.UTF8.GetBytes($"{apiKey}:{secretKey}")));

using var timer = new PeriodicTimer(TimeSpan.FromMinutes(1));
do
{
    // Each message is returned once: store it before the next call.
    var result = await http.GetFromJsonAsync<ApiEnvelope<List<InboundMessage>>>(
        "v1/inbound_messages?limit=500")
        ?? throw new InvalidOperationException("Empty response from everymessage");

    switch (result.ResponseStatusReason)
    {
        case null:
            foreach (var m in result.Body ?? [])
                Console.WriteLine($"{m.DateTime} from {m.Sender} to {m.InboxNumber}: {m.Content}");
            break;
        case "NO_CURRENT_ENTRIES":
            break; // nothing new
        default:
            throw new InvalidOperationException($"Collect failed: {result.ResponseStatusReason}");
    }
}
while (await timer.WaitForNextTickAsync());

record ApiEnvelope<T>(int ResponseStatusCode, string? ResponseStatusReason, int ProcessingTime, T? Body);
record InboundMessage(string Type, long MessageId, string Sender, string? InboxName,
    string? InboxNumber, string? InboxKeyword, string Content, string DateTime);