C# Quick Start Guide

Get started with FacePing's face recognition API using C#

Prerequisites

A FacePing API key
.NET 6.0 or higher installed
Basic knowledge of C# and async/await

Installation

First, create a new C# project and install required packages:

dotnet new console -n FacePingDemo
cd FacePingDemo
dotnet add package Microsoft.Extensions.Configuration.Json

Add your API key to appsettings.json:

{
  "FacePing": {
    "ApiKey": "your_api_key_here"
  }
}

Step 1: Create Face Group

Create a new file FacePingClient.cs with the basic client setup:

using System.Net.Http.Headers;
using System.Text.Json;

public class FacePingClient
{
    private readonly HttpClient _client;
    private readonly string _apiKey;

    public FacePingClient(string apiKey)
    {
        _apiKey = apiKey;
        _client = new HttpClient
        {
            BaseAddress = new Uri("https://api.faceping.ai")
        };
        _client.DefaultRequestHeaders.Authorization = 
            new AuthenticationHeaderValue("Bearer", _apiKey);
    }

    public async Task CreateGroupAsync(string groupName)
    {
        try
        {
            var response = await _client.PostAsync($"/groups/{groupName}", null);
            
            if (response.IsSuccessStatusCode)
            {
                Console.WriteLine($"Group '{groupName}' created successfully");
                return true;
            }
            
            Console.WriteLine($"Error creating group: {response.StatusCode}");
            return false;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
            return false;
        }
    }
}

Create Program.cs to use the client:

using Microsoft.Extensions.Configuration;

var config = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json")
    .Build();

var apiKey = config["FacePing:ApiKey"];
var client = new FacePingClient(apiKey);

await client.CreateGroupAsync("my-group");

Step 2: Upload Face Image

Add the upload method to FacePingClient.cs:

public async Task UploadFaceAsync(string groupName, string imagePath)
{
    if (!File.Exists(imagePath))
    {
        Console.WriteLine("Image file not found");
        return false;
    }

    try
    {
        using var form = new MultipartFormDataContent();
        using var fileContent = new ByteArrayContent(await File.ReadAllBytesAsync(imagePath));
        
        fileContent.Headers.ContentType = 
            MediaTypeHeaderValue.Parse("image/jpeg");
        
        form.Add(fileContent, "image", Path.GetFileName(imagePath));

        var response = await _client.PostAsync(
            $"/groups/{groupName}/faces",
            form
        );

        if (response.IsSuccessStatusCode)
        {
            Console.WriteLine("Face uploaded successfully");
            return true;
        }

        Console.WriteLine($"Error uploading face: {response.StatusCode}");
        return false;
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error: {ex.Message}");
        return false;
    }
}

Use it in Program.cs:

await client.UploadFaceAsync("my-group", "path/to/face.jpg");

Step 3: Search for Faces

Add the search method to FacePingClient.cs:

public class MatchResult
{
    public double Score { get; set; }
}

public class SearchResponse
{
    public List Matches { get; set; } = new();
}

public async Task> SearchFacesAsync(string groupName, string imagePath)
{
    if (!File.Exists(imagePath))
    {
        Console.WriteLine("Image file not found");
        return new List();
    }

    try
    {
        using var form = new MultipartFormDataContent();
        using var fileContent = new ByteArrayContent(await File.ReadAllBytesAsync(imagePath));
        
        fileContent.Headers.ContentType = 
            MediaTypeHeaderValue.Parse("image/jpeg");
        
        form.Add(fileContent, "image", Path.GetFileName(imagePath));

        var response = await _client.PostAsync(
            $"/groups/{groupName}/search",
            form
        );

        if (response.IsSuccessStatusCode)
        {
            var content = await response.Content.ReadAsStringAsync();
            var result = JsonSerializer.Deserialize(content);
            
            Console.WriteLine($"Found {result?.Matches.Count} matches");
            return result?.Matches ?? new List();
        }

        Console.WriteLine($"Error searching faces: {response.StatusCode}");
        return new List();
    }
    catch (Exception ex)
    {
        Console.WriteLine($"Error: {ex.Message}");
        return new List();
    }
}