Step by Step Guide to Building an EmailOctopus API Integration in Go

Aug 16, 2024 • 6 minute read

Hey there, fellow Go enthusiast! Ready to dive into the world of email marketing with EmailOctopus? Let's build an awesome API integration that'll have you managing lists and contacts like a pro. Buckle up, and let's get coding!

Introduction

EmailOctopus is a fantastic tool for email marketing, and their API opens up a world of possibilities. We're going to harness that power with Go, creating a sleek integration that'll make your email campaigns a breeze to manage programmatically.

Prerequisites

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

Go installed (you're a Gopher, right?)
An EmailOctopus API key (grab one from your account settings)
Your favorite code editor ready to rock

Setting up the project

Let's kick things off by creating a new Go module:

mkdir emailoctopus-integration
cd emailoctopus-integration
go mod init github.com/yourusername/emailoctopus-integration

Now, let's grab the HTTP client we'll need:

go get github.com/go-resty/resty/v2

Configuring the API client

Time to set up our API client. Create a new file called client.go:

package emailoctopus

import (
    "github.com/go-resty/resty/v2"
)

const baseURL = "https://emailoctopus.com/api/1.6"

type Client struct {
    apiKey string
    http   *resty.Client
}

func NewClient(apiKey string) *Client {
    return &Client{
        apiKey: apiKey,
        http:   resty.New().SetBaseURL(baseURL),
    }
}

Implementing core functionality

Let's add some methods to our client to interact with EmailOctopus. We'll start with creating a list:

func (c *Client) CreateList(name string) (string, error) {
    resp, err := c.http.R().
        SetQueryParam("api_key", c.apiKey).
        SetBody(map[string]string{"name": name}).
        Post("/lists")
    
    if err != nil {
        return "", err
    }
    
    // Parse the response and return the list ID
    // You'll need to implement this based on the API response
}

Now, let's add a method to add contacts to a list:

func (c *Client) AddContact(listID, email string) error {
    _, err := c.http.R().
        SetQueryParam("api_key", c.apiKey).
        SetBody(map[string]string{"email_address": email}).
        Post("/lists/" + listID + "/contacts")
    
    return err
}

Error handling and rate limiting

EmailOctopus has rate limits, so let's be good citizens and implement some retry logic:

func (c *Client) retryableRequest(req *resty.Request) (*resty.Response, error) {
    var resp *resty.Response
    var err error
    
    for i := 0; i < 3; i++ {
        resp, err = req.Send()
        if err == nil && resp.StatusCode() < 429 {
            return resp, nil
        }
        time.Sleep(time.Second * time.Duration(i+1))
    }
    
    return resp, err
}

Testing the integration

Don't forget to test your code! Here's a quick example:

func TestCreateList(t *testing.T) {
    client := NewClient("your-api-key")
    listID, err := client.CreateList("My Awesome List")
    if err != nil {
        t.Fatalf("Failed to create list: %v", err)
    }
    t.Logf("Created list with ID: %s", listID)
}

Best practices and optimization

Remember to cache list IDs and contact information when possible to reduce API calls. Also, consider implementing bulk operations for adding multiple contacts at once.

Conclusion

And there you have it! You've just built a solid foundation for integrating EmailOctopus into your Go projects. From here, you can expand on this integration, adding more features like campaign management or detailed reporting.

Keep exploring, keep coding, and most importantly, have fun with it! The world of email marketing automation is now at your fingertips.

Resources

Happy coding, Gophers! 🐙🚀