diff --git a/.gitignore b/.gitignore
index 8fc5d4a..d687fc7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,8 @@
 client/node_modules
 client/dist
 
+.vs
+
 # Build results
 [Dd]ebug/
 [Dd]ebugPublic/
diff --git a/server/3cx_Tapi.sln b/server/3cx_Tapi.sln
new file mode 100644
index 0000000..6343ddc
--- /dev/null
+++ b/server/3cx_Tapi.sln
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 18
+VisualStudioVersion = 18.5.11612.153 insiders
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CPATapi.Server", "src\CPATapi.Server\CPATapi.Server.csproj", "{7879A024-A074-FE67-0546-8668213BFA99}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{7879A024-A074-FE67-0546-8668213BFA99}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7879A024-A074-FE67-0546-8668213BFA99}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7879A024-A074-FE67-0546-8668213BFA99}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7879A024-A074-FE67-0546-8668213BFA99}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {E2CF5765-9038-4ED6-AC5C-1A3E569ABC6C}
+	EndGlobalSection
+EndGlobal
diff --git a/server/src/CPATapi.Server/CPATapi.Server.csproj b/server/src/CPATapi.Server/CPATapi.Server.csproj
new file mode 100644
index 0000000..81ddb06
--- /dev/null
+++ b/server/src/CPATapi.Server/CPATapi.Server.csproj
@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Dapper" Version="2.0.78" />
+    <PackageReference Include="Microsoft.Data.SqlClient" Version="2.1.2" />
+  </ItemGroup>
+
+
+</Project>
diff --git a/server/src/CPATapi.Server/Controllers/AvailabilityController.cs b/server/src/CPATapi.Server/Controllers/AvailabilityController.cs
new file mode 100644
index 0000000..c876800
--- /dev/null
+++ b/server/src/CPATapi.Server/Controllers/AvailabilityController.cs
@@ -0,0 +1,47 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Dapper;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+
+namespace CPATapi.Server.Controllers
+{
+    [Route("[controller]")]
+    [ApiController]
+    public class AvailabilityController : ControllerBase
+    {
+        private readonly IConfiguration _config;
+        public AvailabilityController(IConfiguration config) => _config = config;
+
+        [HttpGet, Route("users")]
+        public async Task<IEnumerable<string>> GetUsers()
+        {
+            await using var con = new SqlConnection(_config["Db:ConnectionStringZc"]);
+            await con.OpenAsync();
+            return await con.QueryAsync<string>(@"
+SELECT DISTINCT MA_USER_NAME
+FROM dbo.MA_DATEN
+WHERE MA_USER_NAME IS NOT NULL AND MA_USER_AKTIV = 1
+ORDER BY MA_USER_NAME");
+        }
+
+        [HttpGet, Route("{user}")]
+        public async Task<object> GetAvailability(string user)
+        {
+            await using var con = new SqlConnection(_config["Db:ConnectionStringZc"]);
+            await con.OpenAsync();
+            var stampCount = (await con.QueryAsync(@"
+SELECT *
+FROM dbo.BU
+INNER JOIN dbo.MA_DATEN on MA_NR = BU_MA_NR
+WHERE
+  MA_USER_NAME = @user AND
+  BU_BU >= @date AND BU_BU < @tomorrow", new { user, date = DateTime.Now.Date, tomorrow = DateTime.Now.AddDays(1).Date })).Count();
+            return new { user, loggedIn = stampCount % 2 != 0 };
+        }
+    }
+}
diff --git a/server/src/CPATapi.Server/Controllers/CallerIdController.cs b/server/src/CPATapi.Server/Controllers/CallerIdController.cs
new file mode 100644
index 0000000..e8eb430
--- /dev/null
+++ b/server/src/CPATapi.Server/Controllers/CallerIdController.cs
@@ -0,0 +1,42 @@
+using System.Threading.Tasks;
+using CPATapi.Server.Models;
+using Dapper;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+
+namespace CPATapi.Server.Controllers
+{
+    [Route("[controller]")]
+    [ApiController]
+    public class CallerIdController : ControllerBase
+    {
+        private readonly IConfiguration _config;
+        public CallerIdController(IConfiguration config) => _config = config;
+
+
+        [HttpGet, Route("{number}")]
+        public async Task<TapiContact> CallerIdAsync([FromRoute] string number)
+        {
+            if (number.Length >= 5)
+            {
+                var minMatch = number[^5..];
+                number = "%" + minMatch;
+            }
+
+            await using var con = new SqlConnection(_config["Db:ConnectionString"]);
+            await con.OpenAsync();
+
+            var result = await con.QueryFirstOrDefaultAsync<TapiContact>(@"
+SELECT 
+TD_ID,
+TD_NAME,
+TD_NUMBER,
+TD_NUMBER_TAPI,
+TD_MEDIUM
+FROM dbo.CP_TAPI_DIRECTORY
+WHERE TD_NUMBER_TAPI LIKE @number", new {number});
+            return result;
+        }
+    }
+}
diff --git a/server/src/CPATapi.Server/Controllers/ContactController.cs b/server/src/CPATapi.Server/Controllers/ContactController.cs
new file mode 100644
index 0000000..5c4c111
--- /dev/null
+++ b/server/src/CPATapi.Server/Controllers/ContactController.cs
@@ -0,0 +1,43 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using CPATapi.Server.Models;
+using Dapper;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
+
+namespace CPATapi.Server.Controllers
+{
+    [ApiController]
+    [Route("[controller]")]
+    public class ContactController : ControllerBase
+    {
+
+        private readonly ILogger<ContactController> _logger;
+        private readonly IConfiguration _config;
+
+        public ContactController(ILogger<ContactController> logger, IConfiguration config)
+        {
+            _logger = logger;
+            _config = config;
+        }
+
+        [HttpGet]
+        public async Task<IEnumerable<TapiContact>> GetAsync()
+        {
+            await using var con = new SqlConnection(_config["Db:ConnectionString"]);
+            await con.OpenAsync();
+
+            var contacts = await con.QueryAsync<TapiContact>(@"
+SELECT 
+TD_ID,
+TD_NAME,
+TD_NUMBER,
+TD_NUMBER_TAPI,
+TD_MEDIUM
+FROM dbo.CP_TAPI_DIRECTORY");
+            return contacts;
+        }
+    }
+}
diff --git a/server/src/CPATapi.Server/Controllers/SearchController.cs b/server/src/CPATapi.Server/Controllers/SearchController.cs
new file mode 100644
index 0000000..4526197
--- /dev/null
+++ b/server/src/CPATapi.Server/Controllers/SearchController.cs
@@ -0,0 +1,64 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using CPATapi.Server.Models;
+using Dapper;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+
+namespace CPATapi.Server.Controllers
+{
+    [Route("[controller]")]
+    [ApiController]
+    public class SearchController : ControllerBase
+    {
+        private readonly IConfiguration _config;
+        public SearchController(IConfiguration config) => _config = config;
+
+        [HttpGet]
+        public async Task<IEnumerable<TapiContact>> SearchAsync([FromQuery] string query)
+        {
+            if (query == null)
+            {
+                return new List<TapiContact>();
+            }
+
+            var args = Regex.Split(query, "\\s").Where(s => !string.IsNullOrWhiteSpace(s)).Select(s => s.Trim()).ToArray();
+
+            if (args.Length == 0)
+            {
+                return new List<TapiContact>();
+            }
+
+            await using var con = new SqlConnection(_config["Db:ConnectionString"]);
+            await con.OpenAsync();
+            var sql = new StringBuilder(@"
+SELECT TOP 10
+TD_ID,
+TD_NAME,
+TD_NUMBER,
+TD_NUMBER_TAPI,
+TD_MEDIUM
+FROM dbo.CP_TAPI_DIRECTORY
+WHERE ");
+            var first = true;
+            var dp = new DynamicParameters();
+            for (var i = 1; i <= args.Length; i++)
+            {
+                if (!first)
+                {
+                    sql.AppendLine("AND");
+                }
+                first = false;
+                sql.AppendLine($"(TD_NAME LIKE @s{i} OR");
+                sql.AppendLine($" TD_NUMBER_TAPI LIKE @s{i})");
+                dp.Add($"s{i}", $"%{args[i-1]}%");
+            }
+
+            return await con.QueryAsync<TapiContact>(sql.ToString(), dp);
+        }
+    }
+}
diff --git a/server/src/CPATapi.Server/Models/TapiContact.cs b/server/src/CPATapi.Server/Models/TapiContact.cs
new file mode 100644
index 0000000..94bb0cc
--- /dev/null
+++ b/server/src/CPATapi.Server/Models/TapiContact.cs
@@ -0,0 +1,11 @@
+namespace CPATapi.Server.Models
+{
+    public class TapiContact
+    {
+        public string TD_ID { get; set; }
+        public string TD_NAME { get; set; }
+        public string TD_NUMBER { get; set; }
+        public string TD_NUMBER_TAPI { get; set; }
+        public string TD_MEDIUM { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/server/src/CPATapi.Server/Program.cs b/server/src/CPATapi.Server/Program.cs
new file mode 100644
index 0000000..bbc9dc4
--- /dev/null
+++ b/server/src/CPATapi.Server/Program.cs
@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace CPATapi.Server
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            CreateHostBuilder(args).Build().Run();
+        }
+
+        public static IHostBuilder CreateHostBuilder(string[] args) =>
+            Host.CreateDefaultBuilder(args)
+                .ConfigureWebHostDefaults(webBuilder =>
+                {
+                    webBuilder.UseStartup<Startup>();
+                });
+    }
+}
diff --git a/server/src/CPATapi.Server/Properties/launchSettings.json b/server/src/CPATapi.Server/Properties/launchSettings.json
new file mode 100644
index 0000000..37cfe29
--- /dev/null
+++ b/server/src/CPATapi.Server/Properties/launchSettings.json
@@ -0,0 +1,30 @@
+{
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:62406",
+      "sslPort": 0
+    }
+  },
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "profiles": {
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "launchUrl": "contact",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "CPATapiServer": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "launchUrl": "weatherforecast",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      },
+      "applicationUrl": "https://localhost:5001;http://localhost:5000"
+    }
+  }
+}
\ No newline at end of file
diff --git a/server/src/CPATapi.Server/Startup.cs b/server/src/CPATapi.Server/Startup.cs
new file mode 100644
index 0000000..3d9d506
--- /dev/null
+++ b/server/src/CPATapi.Server/Startup.cs
@@ -0,0 +1,46 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+
+namespace CPATapi.Server
+{
+    public class Startup
+    {
+        public Startup(IConfiguration configuration)
+        {
+            Configuration = configuration;
+        }
+
+        public IConfiguration Configuration { get; }
+
+        // This method gets called by the runtime. Use this method to add services to the container.
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services
+                .AddControllers();
+                //.AddJsonOptions(options => options.JsonSerializerOptions.PropertyNamingPolicy = null);
+        }
+
+        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        {
+            if (env.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+
+            //app.UseHttpsRedirection();
+
+            app.UseRouting();
+
+            app.UseAuthorization();
+
+            app.UseEndpoints(endpoints =>
+            {
+                endpoints.MapControllers();
+            });
+        }
+    }
+}
diff --git a/server/src/CPATapi.Server/appsettings.json b/server/src/CPATapi.Server/appsettings.json
new file mode 100644
index 0000000..7caaae0
--- /dev/null
+++ b/server/src/CPATapi.Server/appsettings.json
@@ -0,0 +1,14 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft": "Warning",
+      "Microsoft.Hosting.Lifetime": "Information"
+    }
+  },
+  "Db": {
+    "ConnectionString": "",
+    "ConnectionStringZc": "" 
+  },
+  "AllowedHosts": "*"
+}