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Getting Your API Key

  1. Visit Legnext.ai Dashboard
  2. Navigate to API Keys section
  3. Generate a new API key
  4. Copy and store securely

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Authentication Methods

Set your API key as an environment variable: 
export LEGNEXT_API_KEY="your-api-key-here"
Then use it in your C# code: 
using System;
using Microsoft.Extensions.DependencyInjection;
using Legnext.SDK.Api;
using Legnext.SDK.Client;
using Legnext.SDK.Extensions;

string apiKey = Environment.GetEnvironmentVariable("LEGNEXT_API_KEY");

var services = new ServiceCollection();
services.AddApi(config =>
{
    config.AddApiHttpClients(client =>
    {
        client.BaseAddress = new Uri("https://api.legnext.ai");
    });
});

var provider = services.BuildServiceProvider();
var imageApi = provider.GetRequiredService<IImageApi>();

// Use imageApi with apiKey in method calls
var response = await imageApi.ApiV1DiffusionPostAsync(
    new Option<string>(apiKey),
    request
);

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Method 2: appsettings.json Configuration

For ASP.NET Core applications: appsettings.json: 
{
  "Legnext": {
    "ApiKey": "your-api-key-here",
    "BaseUrl": "https://api.legnext.ai"
  }
}
Usage: 
string apiKey = Configuration["Legnext:ApiKey"];
string baseUrl = Configuration["Legnext:BaseUrl"];

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Method 3: User Secrets (Development)

For development environments: 
dotnet user-secrets init
dotnet user-secrets set "Legnext:ApiKey" "your-api-key-here"
Then access in code: 
string apiKey = Configuration["Legnext:ApiKey"];

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Complete Setup Example

using System;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Legnext.SDK.Api;
using Legnext.SDK.Client;
using Legnext.SDK.Extensions;

public class LegnextService
{
    private readonly IServiceProvider _serviceProvider;
    private readonly string _apiKey;

    public LegnextService(string apiKey)
    {
        _apiKey = apiKey;

        var services = new ServiceCollection();
        services.AddApi(config =>
        {
            config.AddApiHttpClients(client =>
            {
                client.BaseAddress = new Uri("https://api.legnext.ai");
                client.Timeout = TimeSpan.FromMinutes(5);
            });
        });

        _serviceProvider = services.BuildServiceProvider();
    }

    public async Task<string> GenerateImageAsync(string prompt)
    {
        var imageApi = _serviceProvider.GetRequiredService<IImageApi>();

        var request = new Dictionary<string, object>
        {
            { "text", prompt }
        };

        var response = await imageApi.ApiV1DiffusionPostAsync(
            new Option<string>(_apiKey),
            request
        );

        if (response.IsOk)
        {
            var jsonDoc = JsonDocument.Parse(response.RawContent);
            if (jsonDoc.RootElement.TryGetProperty("job_id", out var jobId))
            {
                return jobId.GetString();
            }
        }

        throw new Exception("Failed to generate image");
    }
}

​
Security Best Practices

  1. Never hardcode API keys
  2. Use different keys for different environments
  3. Never commit secrets to version control
  4. Rotate keys regularly
  5. Use secure storage in production (Azure Key Vault, AWS Secrets Manager)
  6. Enable HTTPS only

​
Testing Authentication

using System;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Legnext.SDK.Api;
using Legnext.SDK.Client;
using Legnext.SDK.Extensions;

string apiKey = Environment.GetEnvironmentVariable("LEGNEXT_API_KEY");

var services = new ServiceCollection();
services.AddApi(config =>
{
    config.AddApiHttpClients(client =>
    {
        client.BaseAddress = new Uri("https://api.legnext.ai");
    });
});

var provider = services.BuildServiceProvider();
var accountApi = provider.GetRequiredService<IAccountManagementApi>();

try
{
    var response = await accountApi.ApiAccountBalanceGetAsync(
        new Option<string>(apiKey)
    );

    if (response.IsOk)
    {
        Console.WriteLine("✅ Authentication successful!");

        var jsonDoc = JsonDocument.Parse(response.RawContent);
        if (jsonDoc.RootElement.TryGetProperty("data", out var data))
        {
            if (data.TryGetProperty("balance_usd", out var balance))
            {
                Console.WriteLine($"Balance: ${balance.GetDecimal()} USD");
            }
        }
    }
}
catch (Exception e)
{
    Console.WriteLine("❌ Authentication failed");
    Console.WriteLine($"Error: {e.Message}");
}

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Next Steps