Step by Step Guide to Building an Omnisend API Integration in C#

Hey there, fellow developer! Ready to dive into the world of Omnisend API integration? Let's roll up our sleeves and get coding!

Introduction

Omnisend's API is a powerful tool for automating your marketing efforts. In this guide, we'll walk through building a robust integration in C#. Trust me, it's easier than you might think!

Prerequisites

Before we jump in, make sure you've got:

• Visual Studio or your favorite C# IDE
• .NET Core 3.1 or later
• An Omnisend account with API credentials

Got all that? Great! Let's move on.

Setting up the project

First things first, let's create a new C# project. Fire up your IDE and create a new .NET Core Console Application. Now, let's add some NuGet packages:

dotnet add package Newtonsoft.Json
dotnet add package RestSharp

These will make our lives much easier when dealing with JSON and HTTP requests.

Authentication

Omnisend uses API key authentication. It's straightforward - just include your API key in the headers of each request. Here's a quick example:

var client = new RestClient("https://api.omnisend.com/v3");
client.AddDefaultHeader("X-API-KEY", "your-api-key-here");

Easy peasy, right?

Making API requests

Let's create a base API client class to handle our requests:

public class OmnisendClient
{
    private readonly RestClient _client;

    public OmnisendClient(string apiKey)
    {
        _client = new RestClient("https://api.omnisend.com/v3");
        _client.AddDefaultHeader("X-API-KEY", apiKey);
    }

    public async Task<T> ExecuteAsync<T>(RestRequest request)
    {
        var response = await _client.ExecuteAsync<T>(request);
        if (!response.IsSuccessful)
        {
            throw new Exception($"API request failed: {response.ErrorMessage}");
        }
        return response.Data;
    }
}

This gives us a solid foundation to build upon.

Implementing key Omnisend API endpoints

Now, let's implement some key endpoints. We'll focus on Contacts, Campaigns, and Events.

Contacts API

public async Task<Contact> CreateContact(Contact contact)
{
    var request = new RestRequest("contacts", Method.POST);
    request.AddJsonBody(contact);
    return await ExecuteAsync<Contact>(request);
}

Campaigns API

public async Task<Campaign> GetCampaign(string campaignId)
{
    var request = new RestRequest($"campaigns/{campaignId}", Method.GET);
    return await ExecuteAsync<Campaign>(request);
}

Events API

public async Task TrackEvent(Event eventData)
{
    var request = new RestRequest("events", Method.POST);
    request.AddJsonBody(eventData);
    await ExecuteAsync<object>(request);
}

Error handling and rate limiting

Let's add some retry logic and respect those rate limits:

public async Task<T> ExecuteWithRetry<T>(RestRequest request, int maxRetries = 3)
{
    for (int i = 0; i < maxRetries; i++)
    {
        try
        {
            return await ExecuteAsync<T>(request);
        }
        catch (Exception ex) when (ex.Message.Contains("429"))
        {
            if (i == maxRetries - 1) throw;
            await Task.Delay(1000 * (i + 1));
        }
    }
    throw new Exception("Max retries reached");
}

Testing the integration

Don't forget to test! Here's a quick unit test example using xUnit:

[Fact]
public async Task CreateContact_ReturnsContact()
{
    var client = new OmnisendClient("test-api-key");
    var contact = new Contact { Email = "[email protected]" };
    var result = await client.CreateContact(contact);
    Assert.NotNull(result.Id);
}

Best practices and optimization

Remember to implement caching where appropriate and use asynchronous operations to keep your application responsive. Here's a quick caching example:

private readonly MemoryCache _cache = new MemoryCache(new MemoryCacheOptions());

public async Task<Campaign> GetCampaignWithCache(string campaignId)
{
    if (!_cache.TryGetValue(campaignId, out Campaign campaign))
    {
        campaign = await GetCampaign(campaignId);
        _cache.Set(campaignId, campaign, TimeSpan.FromMinutes(10));
    }
    return campaign;
}

Conclusion

And there you have it! You've just built a solid Omnisend API integration in C#. Remember, this is just the beginning - there's so much more you can do with the Omnisend API. Keep exploring, keep coding, and most importantly, have fun!

For more details, check out the Omnisend API documentation. Happy coding!