diff --git a/ContactsApp.csproj b/ContactsApp.csproj
new file mode 100644
index 0000000..fa1439a
--- /dev/null
+++ b/ContactsApp.csproj
@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="10.0.0" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="10.0.1" />
+  </ItemGroup>
+
+</Project>
diff --git a/ContactsApp.http b/ContactsApp.http
new file mode 100644
index 0000000..0a549e4
--- /dev/null
+++ b/ContactsApp.http
@@ -0,0 +1,6 @@
+@ContactsApp_HostAddress = http://localhost:5246
+
+GET {{ContactsApp_HostAddress}}/weatherforecast/
+Accept: application/json
+
+###
diff --git a/ContactsApp.slnx b/ContactsApp.slnx
new file mode 100644
index 0000000..cd7d5d3
--- /dev/null
+++ b/ContactsApp.slnx
@@ -0,0 +1,3 @@
+<Solution>
+  <Project Path="ContactsApp.csproj" />
+</Solution>
diff --git a/Controllers/ContactController.cs b/Controllers/ContactController.cs
new file mode 100644
index 0000000..eb28f93
--- /dev/null
+++ b/Controllers/ContactController.cs
@@ -0,0 +1,90 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using System.Text.Json;
+
+namespace ContactsApp
+{
+    [ApiController]
+    [Route("api/contacts")]
+    public class ContactController(IContactRepository repository) : ControllerBase
+    {
+        [HttpGet]
+        public ActionResult<IEnumerable<Contact>> GetAll()
+        {
+            var contacts = repository.GetAll().ToList();
+            return Ok(contacts);
+        }
+
+        [HttpPost]
+        public ActionResult<Contact> Create([FromBody] Contact contact)
+        {
+            repository.AddContact(contact);
+            return Ok(contact);
+        }
+
+        [HttpGet("{id:Guid}")]
+        public ActionResult<Contact> GetById(Guid id)
+        {
+            var contact = repository.GetContactById(id);
+            if (contact == null)
+                return NotFound();
+
+            return Ok(contact);
+        }
+        [HttpPost("{id:Guid}")]
+        public ActionResult Update(Guid id, [FromBody] Contact contact)
+        {
+            repository.UpdateContact(id, contact);
+            return Ok();
+        }
+
+        [HttpDelete("{id:Guid}")]
+        public ActionResult Delete(Guid id)
+        {
+            var contact = repository.GetContactById(id);
+            if (contact == null)
+                return NotFound();
+
+            repository.DeleteContact(id);
+            return Ok();
+        }
+
+        [HttpPost("upload")]
+        public async Task<IActionResult> Upload(IFormFile file)
+        {
+            if (file == null || file.Length == 0)
+                return BadRequest("Файл пустой.");
+
+            using var stream = new MemoryStream();
+            await file.CopyToAsync(stream);
+            string json = System.Text.Encoding.UTF8.GetString(stream.ToArray());
+
+            try
+            {
+                repository.LoadJSON(json); // репозиторий сам парсит JSON и обновляет список
+            }
+            catch (Exception ex)
+            {
+                return BadRequest("Ошибка при обработке JSON: " + ex.Message);
+            }
+
+            return Ok("Контакты успешно загружены.");
+        }
+
+        [HttpGet("download")]
+        public IActionResult Download()
+        {
+            string json = repository.SaveJSON(); // репозиторий формирует JSON строку
+            byte[] bytes = System.Text.Encoding.UTF8.GetBytes(json);
+
+            return File(
+                bytes,
+                "application/json",
+                "contacts.json"
+            );
+        }
+
+    }
+}
+
+
diff --git a/IContactRepository.cs b/IContactRepository.cs
new file mode 100644
index 0000000..230ae69
--- /dev/null
+++ b/IContactRepository.cs
@@ -0,0 +1,16 @@
+п»їusing System;
+using System.Threading.Tasks;
+
+namespace ContactsApp
+{
+    public interface IContactRepository
+    {
+        public void AddContact(Contact contact);
+        public void UpdateContact(Guid id, Contact contact);
+        public void DeleteContact(Guid id);
+        public Contact GetContactById(Guid id);
+        public IEnumerable<Contact> GetAll();
+        public void LoadJSON(string file);
+        public string SaveJSON();
+    }
+}
diff --git a/Models/Contact.cs b/Models/Contact.cs
new file mode 100644
index 0000000..c718597
--- /dev/null
+++ b/Models/Contact.cs
@@ -0,0 +1,33 @@
+using System.ComponentModel.DataAnnotations;
+using System.Net.Mail;
+
+namespace ContactsApp
+{
+    public class Contact
+    {
+        public Guid Id { get; }
+        public string Name { get; set; }
+        public string? Email { get; set; }
+        public string Phone { get; set; }
+
+        public Contact(string name, string? email, string phone)
+        {
+            Id = Guid.NewGuid();
+            Name = name;
+            
+            try
+            {
+                var addr = new MailAddress(email);
+                Email = email;
+            }
+            catch (Exception ex)
+            {
+                throw new Exception("Invalid email");
+            }
+
+            Phone = phone;
+        }
+    }
+}
+
+
diff --git a/Program.cs b/Program.cs
new file mode 100644
index 0000000..8bf2641
--- /dev/null
+++ b/Program.cs
@@ -0,0 +1,32 @@
+using Microsoft.AspNetCore.Mvc;
+using Swashbuckle.AspNetCore.Swagger;
+
+
+namespace ContactsApp;
+
+public class Program
+{
+    public static void Main(string[] args)
+    {
+        var builder = WebApplication.CreateBuilder(args);
+
+        // Add services to the container.
+        builder.Services.AddControllers();
+        builder.Services.AddAuthorization();
+        builder.Services.AddSwaggerGen();
+
+        builder.Services.AddSingleton<IContactRepository, ContactRepository>();
+
+        var app = builder.Build();
+
+        // Configure the HTTP request pipeline.
+        // Запрос -> Компу -> По порту -> Приложение -> Kestrel -> (HttpContext) Middlewares -> Controller (mapping) -> AfterMethod -> Method -> BeforeMethod
+        app.UseAuthorization();
+        app.UseSwagger();
+        app.UseSwaggerUI();
+        
+
+        app.MapControllers();
+        app.Run();
+    }
+}
\ No newline at end of file
diff --git a/Properties/launchSettings.json b/Properties/launchSettings.json
new file mode 100644
index 0000000..883ff9b
--- /dev/null
+++ b/Properties/launchSettings.json
@@ -0,0 +1,15 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": false,
+      "launchUrl": "swagger",
+      "applicationUrl": "http://localhost:5043",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}
diff --git a/Repositories/ContactRepository.cs b/Repositories/ContactRepository.cs
new file mode 100644
index 0000000..c8e8823
--- /dev/null
+++ b/Repositories/ContactRepository.cs
@@ -0,0 +1,64 @@
+п»їusing Microsoft.Win32;
+using System;
+using System.Runtime;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace ContactsApp
+{
+    public class ContactRepository : IContactRepository
+    {
+        List<Contact> Contacts = new ();
+
+
+        public void AddContact(Contact contact)
+        {
+            CheckUnique(contact);
+            Contacts.Add(contact);
+        }
+
+        public void UpdateContact(Guid id, Contact contact)
+        {
+            CheckUnique(contact);
+            Contact previous = GetContactById(id);
+            if (previous == null)
+            {
+                Contacts.Add(contact);
+                return;
+            }
+            
+            previous.Name = contact.Name;
+            previous.Email = contact.Email;
+            previous.Phone = contact.Phone;
+        }
+
+        public void DeleteContact(Guid id)
+        {
+            var contact = GetContactById(id);
+            if (contact == null)
+                return;
+            Contacts.Remove(contact);
+        }
+
+        public Contact GetContactById(Guid id)
+        {
+            return Contacts.Find(x => x.Id == id);
+        }
+        public void LoadJSON(string json)
+        {
+            var list = JsonSerializer.Deserialize<List<Contact>>(json);
+            Contacts.AddRange(list);
+        }
+        public string SaveJSON()
+        {
+            return JsonSerializer.Serialize(Contacts, new JsonSerializerOptions { WriteIndented = true });
+        }
+
+        public IEnumerable<Contact> GetAll() => Contacts;
+        private void CheckUnique(Contact contact)
+        {
+            if (Contacts.FirstOrDefault(x => x.Equals(contact)) != null)
+                throw new Exception("Такой контакт уже есть");
+        }
+    }
+}
diff --git a/appsettings.Development.json b/appsettings.Development.json
new file mode 100644
index 0000000..0c208ae
--- /dev/null
+++ b/appsettings.Development.json
@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}
diff --git a/appsettings.json b/appsettings.json
new file mode 100644
index 0000000..10f68b8
--- /dev/null
+++ b/appsettings.json
@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}