var clients = new List<Client>() { 
    new Client { Id = "638f2a30-ca73-4772-b827-f9e6d0e81a86", Address = "ул. Улица", Name = "Иван" }, 
    new Client { Id = "638f2a30-ca73-4772-b827-f9e6d0e81a89", Address = "ул. Бульвар", Name = "Петр" }  
};

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.MapGet("/getClients", () =>
{
    return clients;
})
 .WithName("GetClients");

app.MapGet("getClient/{id}", (string id) =>
{
    Client? client = clients.FirstOrDefault(x => x.Id == id);
    if (client == null)
        return Results.NotFound(new { message = "Клиент не найден" });
    return Results.Json(client);
})
.WithName("GetClient");

app.MapPost("createClient", (Client client) =>
{
    client.Id = Guid.NewGuid().ToString();
    clients.Add(client);
    return client;
})
 .WithName("CreateClient");

app.MapPut("updateClient/{id}", (Client data) =>
{
    Client? client = clients.FirstOrDefault(x => x.Id == data.Id);
    if (client == null)
        return Results.NotFound(new { message = "Клиент не найден" });
    client.Address = data.Address;
    client.Name = data.Name;
    return Results.Json(client);
})
.WithName("UpdateClient");

app.MapDelete("deleteClient/{id}", (string id) =>
{
    Client? client = clients.FirstOrDefault(x => x.Id == id);
    if (client == null)
        return Results.NotFound(new { message = "Клиент не найден" });
    clients.Remove(client);
    return Results.Ok();
})
 .WithName("DeleteClient");

app.Run();
public class Client
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
}