Rich Communication Services (RCS) is the next evolution of SMS messaging, offering enhanced features like rich media, interactive buttons, and quick replies. In this tutorial, we'll build a Go application that implements RCS messaging using the Pinnacle API, complete with media cards, quick replies, and webhook handling for interactive responses.

Pre-reqs

Go installed on your system
Basic understanding of Go programming
(Optional, but recommended) Your own registered agent (Register here)
A Pinnacle API key (Get yours here)
(optional) ngrok or similar tool for webhook testing

Project Setup

First, let's set up our project structure and dependencies. We'll need to install the godotenv package for environment variable management:

bash
go mod init rcs-demo
go get github.com/joho/godotenv # Used to load our .env

Create a .env file in your project root:

PINNACLE_API_KEY=your_api_key_here

Creating the Pinnacle Client

We'll start by creating a client struct to handle our API interactions:

go
type PinnacleClient struct {
    apiKey  string
    baseURL string
    client  *http.Client
}

I'd recommend loading your api key from the .env file using the package godotenv.

Implementing RCS Message Types

Now that we a connection to our client, we can start sending messages.

Sending a Basic Text Message

Let's start with a simple text message:

go
func send_basic_rcs() {
    url := client.baseURL + "/send/rcs"
    payloadData := map[string]interface{}{
        "from": "test",
        "to":   "your_number",

Once we send this, we should see a text from our agent that says "Hello, World!"

2. Quick Reply Buttons

Next, we'll add quick reply buttons that users can tap:

go
func send_rcs_with_quick_replies() {
    payloadData := map[string]interface{}{
        "from": "test",
        "to":   "+16287261512",
        "text": "Hello, World!",

3. Media Cards

For rich media content, we can create cards with images or videos:

go
func send_rcs_media_card() {
    payloadData := map[string]interface{}{
        "from": "test",
        "to":   "+16287261512",
        "cards": []map[string]interface{}{

Handling Webhooks

To make our program interactive, we'll implement a webhook handler to process user responses:

go
func webhookHandler(w http.ResponseWriter, r *http.Request) {
    // Parse incoming webhook data
    var webhookData map[string]interface{}
    if err := json.Unmarshal(body, &webhookData)