Step by Step Guide to Building a lemlist API Integration in C#

Introduction

Hey there, fellow developer! Ready to supercharge your outreach game with lemlist? Let's dive into building a robust C# integration for the lemlist API. This powerhouse tool will help you manage campaigns, leads, and email activities like a pro. Buckle up!

Prerequisites

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

• Visual Studio or your favorite C# IDE
• .NET Core 3.1 or later
• A lemlist account with API access (grab that API key!)

Setting up the project

First things first, let's get our project off the ground:

1. Fire up Visual Studio and create a new C# Console Application.
2. Install the necessary NuGet packages:

Install-Package Newtonsoft.Json
Install-Package Microsoft.Extensions.Http

Configuring the API client

Time to set up our HTTP client:

using System.Net.Http;
using System.Net.Http.Headers;

public class LemlistClient
{
    private readonly HttpClient _httpClient;

    public LemlistClient(string apiKey)
    {
        _httpClient = new HttpClient
        {
            BaseAddress = new Uri("https://api.lemlist.com/api/")
        };
        _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
    }
}

Implementing core API functions

Let's tackle some key lemlist operations:

Handling campaigns

public async Task<List<Campaign>> GetCampaignsAsync()
{
    var response = await _httpClient.GetAsync("campaigns");
    response.EnsureSuccessStatusCode();
    var content = await response.Content.ReadAsStringAsync();
    return JsonConvert.DeserializeObject<List<Campaign>>(content);
}

Managing leads

public async Task<Lead> AddLeadAsync(string campaignId, Lead lead)
{
    var json = JsonConvert.SerializeObject(lead);
    var content = new StringContent(json, Encoding.UTF8, "application/json");
    var response = await _httpClient.PostAsync($"campaigns/{campaignId}/leads", content);
    response.EnsureSuccessStatusCode();
    var responseContent = await response.Content.ReadAsStringAsync();
    return JsonConvert.DeserializeObject<Lead>(responseContent);
}

Error handling and rate limiting

Don't let those pesky errors catch you off guard:

private async Task<T> ExecuteWithRetryAsync<T>(Func<Task<T>> operation, int maxRetries = 3)
{
    for (int i = 0; i < maxRetries; i++)
    {
        try
        {
            return await operation();
        }
        catch (HttpRequestException ex) when (ex.StatusCode == System.Net.HttpStatusCode.TooManyRequests)
        {
            if (i == maxRetries - 1) throw;
            await Task.Delay(TimeSpan.FromSeconds(Math.Pow(2, i)));
        }
    }
    throw new Exception("Max retries exceeded");
}

Asynchronous operations

Keep things smooth with async/await:

public async Task<List<EmailActivity>> GetEmailActivitiesAsync(string campaignId)
{
    return await ExecuteWithRetryAsync(async () =>
    {
        var response = await _httpClient.GetAsync($"campaigns/{campaignId}/activities");
        response.EnsureSuccessStatusCode();
        var content = await response.Content.ReadAsStringAsync();
        return JsonConvert.DeserializeObject<List<EmailActivity>>(content);
    });
}

Testing the integration

Don't forget to put your code through its paces:

[Fact]
public async Task GetCampaigns_ReturnsListOfCampaigns()
{
    var client = new LemlistClient("your-api-key");
    var campaigns = await client.GetCampaignsAsync();
    Assert.NotEmpty(campaigns);
}

Best practices and optimization

• Cache frequently accessed data to reduce API calls.
• Use bulk operations when possible to minimize requests.
• Implement proper logging for easier debugging.

Conclusion

And there you have it! You've just built a solid lemlist API integration in C#. Remember, this is just the beginning – there's a whole world of possibilities to explore with the lemlist API. Keep experimenting, and happy coding!

For more details, check out the official lemlist API documentation. Now go forth and conquer those email campaigns!