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

Introduction

Hey there, fellow developer! Ready to supercharge your C# project with OpenPhone's powerful API? You're in the right place. We're going to walk through building a robust integration that'll have you managing phone numbers, sending messages, and handling calls like a pro. Let's dive in!

Prerequisites

Before we get our hands dirty, make sure you've got:

• Visual Studio or your favorite C# IDE
• .NET Core 3.1 or later
• An OpenPhone 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 Console Application. We'll keep it simple for now, but feel free to adapt this to your specific needs.

Now, let's grab the packages we need. Open up your terminal in the project directory and run:

dotnet add package RestSharp
dotnet add package Newtonsoft.Json

These will handle our HTTP requests and JSON parsing, respectively.

Authentication

Alright, time to get cozy with the OpenPhone API. We'll create a base HTTP client that we'll use for all our requests. Here's how:

using RestSharp;
using RestSharp.Authenticators;

public class OpenPhoneClient
{
    private readonly RestClient _client;

    public OpenPhoneClient(string apiKey)
    {
        _client = new RestClient("https://api.openphone.com/v1");
        _client.Authenticator = new JwtAuthenticator(apiKey);
    }

    // We'll add more methods here later
}

Core API Interactions

Now for the fun part! Let's implement some core functionality.

Fetching phone numbers

public async Task<List<PhoneNumber>> GetPhoneNumbersAsync()
{
    var request = new RestRequest("phone_numbers", Method.GET);
    var response = await _client.ExecuteAsync<List<PhoneNumber>>(request);
    return response.Data;
}

Sending SMS messages

public async Task<bool> SendSmsAsync(string from, string to, string message)
{
    var request = new RestRequest("messages", Method.POST);
    request.AddJsonBody(new
    {
        from,
        to,
        text = message
    });
    var response = await _client.ExecuteAsync(request);
    return response.IsSuccessful;
}

Error Handling and Rate Limiting

Let's be good API citizens and handle errors gracefully while respecting rate limits:

private async Task<IRestResponse> ExecuteWithRetryAsync(RestRequest request)
{
    int maxRetries = 3;
    for (int i = 0; i < maxRetries; i++)
    {
        var response = await _client.ExecuteAsync(request);
        if (response.StatusCode != System.Net.HttpStatusCode.TooManyRequests)
            return response;

        await Task.Delay(1000 * (i + 1)); // Exponential backoff
    }
    throw new Exception("Max retries exceeded");
}

Webhooks Integration

OpenPhone can send you real-time updates. Here's a basic webhook handler:

[ApiController]
[Route("api/[controller]")]
public class WebhookController : ControllerBase
{
    [HttpPost]
    public IActionResult HandleWebhook([FromBody] WebhookPayload payload)
    {
        // Process the webhook payload
        // You might want to queue this for processing if it's a heavy operation
        return Ok();
    }
}

Testing the Integration

Don't forget to test! Here's a quick unit test to get you started:

[Fact]
public async Task SendSms_ValidInput_ReturnsTrue()
{
    var client = new OpenPhoneClient("your-api-key");
    var result = await client.SendSmsAsync("+1234567890", "+0987654321", "Hello, World!");
    Assert.True(result);
}

Best Practices and Optimization

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

private Dictionary<string, object> _cache = new Dictionary<string, object>();

public async Task<T> GetOrCreateAsync<T>(string key, Func<Task<T>> factory)
{
    if (_cache.TryGetValue(key, out var value))
        return (T)value;

    var result = await factory();
    _cache[key] = result;
    return result;
}

Conclusion

And there you have it! You've just built a solid foundation for your OpenPhone API integration. Remember, this is just the beginning. The OpenPhone API has a lot more to offer, so don't be afraid to explore and expand on what we've covered here.

Keep coding, keep learning, and most importantly, have fun with it! If you run into any snags, the OpenPhone API docs are your best friend. Happy integrating!