Developer Guide: Sending SMS with MessageBird and Next.js

This guide provides a complete walkthrough for integrating the MessageBird SMS API into a Next.js application to send outbound text messages. We'll build a simple web form that captures a recipient's phone number and a message, then uses a Next.js API route to securely send the SMS via MessageBird using their Node.js SDK.

This implementation solves the common need to programmatically send SMS notifications, alerts, or messages directly from a web application, leveraging the serverless functions provided by Next.js for backend logic.

Prerequisites:

• Node.js (LTS version recommended) and npm/yarn installed.
• A MessageBird account with a valid API key.
• A registered phone number (either purchased from MessageBird or verified) to use as the originator.
• Basic understanding of React and Next.js concepts.

Project Overview and Goals

Goal: To create a Next.js application enabling users to send an SMS message to a specified phone number via a simple web interface, using MessageBird as the SMS provider.

Problem Solved: Provides a foundational implementation for adding SMS capabilities to any Next.js project, suitable for sending notifications, confirmations, or other transactional messages.

Technologies Used:

• Next.js: A React framework providing server-side rendering, static site generation, and API routes, ideal for building full-stack web applications.
• Node.js: The runtime environment for Next.js and the MessageBird SDK.
• MessageBird Node.js SDK: Simplifies interaction with the MessageBird REST API for sending SMS.
• MessageBird API: The underlying service used for dispatching SMS messages globally.

System Architecture:

+-----------------+      +---------------------+      +--------------------+      +-------------------+
| User (Browser)  | ---> | Next.js Frontend  | ---> | Next.js API Route | ---> | MessageBird API |
| (Input Form)    |      | (React Component)   |      | (/api/send-sms)   |      | (Sends SMS)       |
+-----------------+      +---------------------+      +--------------------+      +-------------------+
       |                                                       ^
       | (Success/Error)                                       | (API Key)
       +-------------------------------------------------------+

1. The user enters a recipient number and message into the Next.js frontend form.
2. On submission, the frontend makes an HTTP POST request to the Next.js API route (/api/send-sms).
3. The API route initializes the MessageBird SDK using the stored API key.
4. The API route calls the MessageBird API to send the SMS.
5. The MessageBird API sends the SMS to the recipient.
6. The API route returns a success or error response to the frontend.
7. The frontend displays feedback to the user.

Final Outcome: A functional Next.js application with a page containing a form. Submitting the form sends an SMS message using the MessageBird API via a secure backend API route.

1. Setting up the Project

Let's start by creating a new Next.js project and installing the necessary dependencies.

Step 1: Create a Next.js App

Open your terminal and run the following command to create a new Next.js project. Replace messagebird-nextjs-sms with your desired project name.

npx create-next-app@latest messagebird-nextjs-sms

Follow the prompts. Note: While create-next-app might default to the App Router, this guide uses the Pages Router structure (pages/api/send-sms.js, pages/index.js) for demonstrating the API route and frontend form.

Step 2: Navigate to Project Directory

cd messagebird-nextjs-sms

Step 3: Install MessageBird Node.js SDK

Install the official MessageBird SDK for Node.js.

npm install messagebird
# or using yarn
# yarn add messagebird

Step 4: Set up Environment Variables

API keys should never be hardcoded directly into your source code. We'll use environment variables. Next.js has built-in support for environment variables using .env.local files.

Create a file named .env.local in the root of your project:

touch .env.local

Open .env.local and add your MessageBird API Key and the originator phone number (or alphanumeric sender ID). You will obtain these in the next section.

# .env.local

MESSAGEBIRD_ACCESS_KEY=YOUR_MESSAGEBIRD_LIVE_API_KEY
MESSAGEBIRD_ORIGINATOR=YOUR_SENDER_ID_OR_NUMBER

• MESSAGEBIRD_ACCESS_KEY: Your live API access key from the MessageBird dashboard.
• MESSAGEBIRD_ORIGINATOR: The phone number (in E.164 format, e.g., +12025550182) or alphanumeric sender ID (max 11 chars, country restrictions apply) that the SMS will appear to be sent from.

Important: Add .env.local to your .gitignore file (it should be there by default in create-next-app) to prevent accidentally committing your secret keys.

Project Structure (Simplified - Pages Router):

messagebird-nextjs-sms/
├── .env.local           # Your secret API key and originator
├── .gitignore
├── node_modules/
├── pages/
│   ├── api/
│   │   └── send-sms.js  # Our API endpoint logic
│   └── index.js         # Our frontend page with the form
├── public/
├── styles/              # Contains CSS modules or global styles
├── package.json
└── ... other config files

Why .env.local? Next.js automatically loads variables from this file into process.env on the server side (including API routes). Variables prefixed with NEXT_PUBLIC_ would be exposed to the browser – we do not want that for our API key.

2. Getting MessageBird Credentials

Before building the API endpoint, you need your MessageBird API key and an originator (sender ID or number).

Step 1: Access the MessageBird Dashboard

Log in to your MessageBird Dashboard.

Step 2: Find/Create Your API Key

• Navigate to the ""Developers"" section in the left-hand sidebar.
• Click on the ""API access"" tab.
• You will see options for ""Live API Key"" and ""Test API Key"". For sending actual messages, you need the Live API Key.
• Copy the Live API Key. If you don't have one, you might need to create it.
• Paste this key into your .env.local file as the value for MESSAGEBIRD_ACCESS_KEY.

Step 3: Determine Your Originator

• This is the ""from"" address for your SMS. It can be:
  • A Virtual Mobile Number: Purchase one from MessageBird under the ""Numbers"" section. These are recommended for two-way communication and better deliverability in many regions. Use the full number in E.164 format (e.g., +12025550182).
  • An Alphanumeric Sender ID: A custom name (e.g., MyApp, max 11 characters). Go to Developers > Sender IDs to register one. Note: Alphanumeric IDs are not supported in all countries (e.g., USA, Canada) and cannot receive replies.
  • A Verified Number: You might be able to use your own verified mobile number in some cases, but purchasing a dedicated number is generally preferred for applications.
• Paste your chosen originator into your .env.local file as the value for MESSAGEBIRD_ORIGINATOR.

Security Note: Treat your Live API Key like a password. Do not share it publicly or commit it to version control.

3. Building the API Endpoint (/api/send-sms)

Now, let's create the Next.js API route that will handle the SMS sending logic. API routes in Next.js (using the Pages Router) provide a seamless way to build backend functionality within your frontend project.

Step 1: Create the API Route File

Create a new file: pages/api/send-sms.js

Step 2: Implement the API Logic

Paste the following code into pages/api/send-sms.js:

// pages/api/send-sms.js

// Import the MessageBird SDK initializer
import { initClient } from 'messagebird';

// Initialize the MessageBird client with your API key
// Ensure MESSAGEBIRD_ACCESS_KEY is set in your .env.local file
const messagebird = initClient(process.env.MESSAGEBIRD_ACCESS_KEY);

export default function handler(req, res) {
  // Only allow POST requests
  if (req.method !== 'POST') {
    res.setHeader('Allow', ['POST']);
    return res.status(405).json({ message: `Method ${req.method} Not Allowed` });
  }

  // Extract recipient and message body from the request
  const { recipient, body } = req.body;

  // Basic validation
  if (!recipient || !body) {
    return res.status(400).json({ message: 'Recipient and message body are required.' });
  }

  // Get the originator from environment variables
  const originator = process.env.MESSAGEBIRD_ORIGINATOR;
  if (!originator) {
      console.error('Error: MESSAGEBIRD_ORIGINATOR environment variable not set.');
      return res.status(500).json({ message: 'Server configuration error: Originator not set.' });
  }

  // Prepare the message parameters
  const params = {
    originator: originator,
    recipients: [recipient], // Must be an array
    body: body,
  };

  console.log(`Sending SMS via MessageBird: To=${recipient}, From=${originator}, Body="${body}"`);

  // Use the MessageBird SDK to send the message
  messagebird.messages.create(params, function (err, response) {
    if (err) {
      // Handle MessageBird API errors
      console.error('MessageBird API Error:', err);
      // Provide more specific error details if available
      const errorDetails = err.errors ? err.errors.map(e => `${e.description} (Code: ${e.code})`).join(', ') : err.message;
      return res.status(500).json({
        message: `Failed to send SMS. ${errorDetails}`,
        error: err, // Optionally include raw error in development
      });
    }

    // Handle successful response
    console.log('MessageBird API Success:', response);
    // Check status from the response if needed, e.g., response.recipients.items[0].status
    return res.status(200).json({
      message: 'SMS sent successfully!',
      details: response, // Optionally include raw response
    });
  });
}

Code Explanation:

1. Import SDK: We import the initClient function from the messagebird package.
2. Initialize Client: We call initClient with the API key loaded from process.env.MESSAGEBIRD_ACCESS_KEY. This must be done outside the handler function for efficiency.
3. Handler Function: The default export is the function Next.js runs for requests to /api/send-sms.
4. Method Check: We ensure only POST requests are processed, returning a 405 Method Not Allowed otherwise. This is standard practice for API endpoints that perform actions.
5. Body Parsing: Next.js automatically parses the JSON body of POST requests into req.body. We extract recipient and body.
6. Basic Validation: We check if recipient and body are present, returning a 400 Bad Request if not. More robust validation should be added in production (see Security section).
7. Originator Check: We fetch the originator from environment variables and return a 500 error if it's missing, indicating a server configuration issue.
8. Prepare Parameters: We create the params object required by the messagebird.messages.create method, ensuring recipients is an array.
9. Logging: We log the attempt to send the SMS for debugging purposes.
10. Send Message: We call messagebird.messages.create with the parameters and a callback function.
11. Error Handling (Callback):
    • If the err object exists in the callback, an error occurred during the API call (network issue, invalid key, invalid parameters, etc.).
    • We log the detailed error using console.error.
    • We return a 500 Internal Server Error response to the frontend with a user-friendly message and potentially more details from err.errors.
12. Success Handling (Callback):
    • If err is null, the API call was successful (though delivery isn't guaranteed instantly).
    • We log the success response.
    • We return a 200 OK response to the frontend.

4. Creating the Frontend Interface

Let's build a simple React component on the main page (pages/index.js) to collect the recipient number and message, and then call our API endpoint.

Step 1: Modify the Index Page

Replace the contents of pages/index.js with the following code:

// pages/index.js

import { useState } from 'react';
import Head from 'next/head';
import styles from '../styles/Home.module.css'; // Assuming default styles

export default function Home() {
  const [recipient, setRecipient] = useState('');
  const [messageBody, setMessageBody] = useState('');
  const [statusMessage, setStatusMessage] = useState('');
  const [isLoading, setIsLoading] = useState(false);
  const [isError, setIsError] = useState(false);

  const handleSubmit = async (event) => {
    event.preventDefault(); // Prevent default form submission
    setIsLoading(true);
    setStatusMessage(''); // Clear previous status
    setIsError(false);

    try {
      const response = await fetch('/api/send-sms', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ recipient, body: messageBody }),
      });

      const result = await response.json();

      if (!response.ok) {
        // Handle errors from the API route (e.g., 4xx, 5xx)
        throw new Error(result.message || `HTTP error! status: ${response.status}`);
      }

      // Handle success
      setStatusMessage(result.message || 'SMS sent successfully!');
      setRecipient(''); // Clear form on success
      setMessageBody('');

    } catch (error) {
      // Handle fetch errors or errors thrown from API response
      console.error(""Sending SMS failed:"", error);
      setStatusMessage(`Error: ${error.message}`);
      setIsError(true);
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <div className={styles.container}&gt;
      <Head&gt;
        <title&gt;Send SMS with Next.js & MessageBird</title&gt;
        <meta name=""description"" content=""Send SMS using Next.js and MessageBird"" /&gt;
        <link rel=""icon"" href=""/favicon.ico"" /&gt;
      </Head&gt;

      <main className={styles.main}&gt;
        <h1 className={styles.title}&gt;
          Send SMS via MessageBird
        </h1&gt;

        <form onSubmit={handleSubmit} className={styles.form}&gt;
          <div className={styles.formGroup}&gt;
            <label htmlFor=""recipient""&gt;Recipient Phone Number:</label&gt;
            <input
              type=""tel""
              id=""recipient""
              value={recipient}
              onChange={(e) =&gt; setRecipient(e.target.value)}
              placeholder=""e.g., +12025550182"" // E.164 format
              required
              disabled={isLoading}
            /&gt;
          </div&gt;

          <div className={styles.formGroup}&gt;
            <label htmlFor=""messageBody""&gt;Message:</label&gt;
            <textarea
              id=""messageBody""
              value={messageBody}
              onChange={(e) =&gt; setMessageBody(e.target.value)}
              required
              rows={4}
              disabled={isLoading}
            /&gt;
          </div&gt;

          <button type=""submit"" disabled={isLoading} className={styles.button}&gt;
            {isLoading ? 'Sending...' : 'Send SMS'}
          </button&gt;
        </form&gt;

        {statusMessage && (
          <p className={`${styles.statusMessage} ${isError ? styles.error : styles.success}`}&gt;
            {statusMessage}
          </p&gt;
        )}
      </main&gt;

      {/* Basic Styling (add to styles/Home.module.css or global.css for production) */}
      {/* Note: Inline JSX styles used here for demonstration purposes. */}
      <style jsx&gt;{`
        .form {
          display: flex;
          flex-direction: column;
          gap: 1rem;
          width: 100%;
          max-width: 400px;
          margin-top: 2rem;
        }
        .formGroup {
          display: flex;
          flex-direction: column;
        }
        label {
          margin-bottom: 0.5rem;
          font-weight: bold;
        }
        input, textarea {
          padding: 0.75rem;
          border: 1px solid #ccc;
          border-radius: 4px;
          font-size: 1rem;
        }
        textarea {
          resize: vertical;
        }
        .button {
          padding: 0.75rem 1.5rem;
          background-color: #0070f3;
          color: white;
          border: none;
          border-radius: 4px;
          font-size: 1rem;
          cursor: pointer;
          transition: background-color 0.2s ease;
        }
        .button:disabled {
          background-color: #ccc;
          cursor: not-allowed;
        }
        .button:hover:not(:disabled) {
          background-color: #005bb5;
        }
        .statusMessage {
          margin-top: 1rem;
          padding: 0.75rem;
          border-radius: 4px;
          text-align: center;
        }
        .success {
          background-color: #d4edda;
          color: #155724;
          border: 1px solid #c3e6cb;
        }
        .error {
          background-color: #f8d7da;
          color: #721c24;
          border: 1px solid #f5c6cb;
        }
      `}</style&gt;
    </div&gt;
  );
}

Code Explanation:

1. State Variables: We use useState to manage the input values (recipient, messageBody), loading state (isLoading), error state (isError), and feedback messages (statusMessage).
2. handleSubmit Function:
   • Prevents the default form submission behavior (which would cause a page reload).
   • Sets isLoading to true and clears previous status messages.
   • Uses the fetch API to make a POST request to our /api/send-sms endpoint.
   • Sets the Content-Type header to application/json.
   • Sends the recipient and messageBody state values in the request body, stringified as JSON.
   • Response Handling:
     • Waits for the response and parses the JSON body using response.json().
     • Checks if response.ok (status code 200-299) is true. If not, it throws an error using the message from the API response (result.message) or a default HTTP error message.
     • If successful, it updates the status message and clears the form fields.
   • Error Handling (catch): Catches network errors during fetch or errors thrown from the non-OK response handling. Logs the error and displays an error message to the user.
   • finally Block: Sets isLoading back to false regardless of success or failure.
3. JSX Form:
   • A standard HTML form element with an onSubmit handler pointing to our handleSubmit function.
   • Input fields (input type=""tel"", textarea) are controlled components, linked to the React state via value and onChange.
   • Placeholders guide the user (e.g., E.164 format for the phone number).
   • The submit button is disabled while isLoading is true.
   • Conditional rendering displays the statusMessage below the form, styled differently based on the isError state.
4. Basic Styling: Inline JSX styles are included for demonstration. In a real application, move these to styles/Home.module.css or a global stylesheet.

5. Running and Testing the Application

Now it's time to run the application and send your first SMS!

Step 1: Start the Development Server

Open your terminal in the project root directory and run:

npm run dev
# or using yarn
# yarn dev

This will start the Next.js development server, usually on http://localhost:3000.

Step 2: Open the Application

Open your web browser and navigate to http://localhost:3000. You should see the "Send SMS via MessageBird" page with the form.

Step 3: Send a Test SMS

1. Recipient Phone Number: Enter a valid phone number (including country code, e.g., +12025550182) that you can receive messages on. Use your own number for testing.
2. Message: Type a short test message.
3. Click "Send SMS".

Step 4: Verify

1. Frontend: Observe the status message below the form. It should indicate "SMS sent successfully!" or display an error.
2. Your Phone: Check the recipient phone number for the incoming SMS message. It should arrive shortly.
3. Developer Console (Browser): Check the browser's developer console (F12) for any potential frontend errors during the fetch call.
4. Terminal Console (Server): Check the terminal where you ran npm run dev. You should see the log messages from the API route (Sending SMS via MessageBird... and MessageBird API Success:... or MessageBird API Error:...).
5. MessageBird Dashboard: Log in to the MessageBird Dashboard and navigate to "SMS" > "Message Logs". You should see a record of the sent message, including its status (e.g., sent, delivered, failed). This is crucial for debugging delivery issues.

6. Error Handling and Logging (Enhancements)

The basic implementation includes error handling, but we can refine it.

API Route (pages/api/send-sms.js) Enhancements:

• More Specific Logging: Log distinct messages for different error types (validation errors, MessageBird API errors, configuration errors).
• Structured Logging: In production, consider using a dedicated logging library (like Pino or Winston) to output structured logs (JSON) which are easier to parse and analyze.
• MessageBird Error Codes: The err object from the MessageBird callback often contains an errors array with specific codes and descriptions (e.g., 2 - invalid username/password, 9 - invalid originator, 10 - destination not reachable). Log these details.

// Example snippet within the callback in pages/api/send-sms.js
  messagebird.messages.create(params, function (err, response) {
    if (err) {
      console.error({
        message: 'MessageBird API Error occurred.',
        recipient: recipient,
        originator: originator,
        errorCode: err.errors ? err.errors[0]?.code : 'N/A',
        errorDescription: err.errors ? err.errors[0]?.description : err.message,
        details: err // Full error object for deeper debugging if needed
      });
      const userMessage = err.errors
         ? `Failed to send SMS: ${err.errors[0].description} (Code: ${err.errors[0].code})`
         : `Failed to send SMS. Please try again later.`;
      return res.status(500).json({ message: userMessage });
    }
    // ... success handling
  });

Frontend (pages/index.js) Enhancements:

• User-Friendly Error Messages: Avoid showing raw technical error details directly to the user. Map common error statuses or messages from the API to simpler explanations.
• Retry Logic (Optional): For transient network errors during the fetch call, you could implement a simple retry mechanism, but be cautious not to bombard the API if the underlying issue persists.

7. Security Considerations

Even for a simple SMS sending feature, security is vital.

• API Key Security:

  • NEVER commit .env.local or expose MESSAGEBIRD_ACCESS_KEY to the frontend JavaScript. Ensure .env.local is in your .gitignore.
  • Use distinct API keys for different environments (development, staging, production).
  • Consider rotating API keys periodically.

• Input Validation (API Route):

  • The current validation (!recipient || !body) is minimal.
  • Phone Number Validation: Use a library (like libphonenumber-js) on the server-side (API route) to validate that the recipient is a plausible phone number format before sending it to MessageBird.
  • Message Length: Check the body length. While MessageBird handles concatenation, you might want to enforce limits or inform the user about multi-part messages for cost reasons.
  • Sanitization: Although less critical for SMS content compared to HTML/SQL, ensure inputs don't contain unexpected characters that could break your system or MessageBird's processing if used elsewhere.

• Rate Limiting (API Route):

  • To prevent abuse (e.g., a bot spamming SMS via your form), implement rate limiting on the /api/send-sms endpoint.
  • Use libraries like rate-limiter-flexible or Vercel's built-in IP rate limiting features. Limit requests per IP address over a specific time window (e.g., 5 requests per minute).

• Authentication/Authorization (If Applicable):

  • If this feature is part of a larger application requiring users to log in, ensure the API route (/api/send-sms) verifies that the user making the request is authenticated and authorized to send SMS messages (e.g., using session cookies, JWTs, or NextAuth.js).

8. Troubleshooting and Caveats

Common issues you might encounter:

• Invalid API Key:

  • Symptom: API route returns 500 error. Terminal logs show MessageBird error (often code 2 - Authentication error).
  • Solution: Double-check MESSAGEBIRD_ACCESS_KEY in .env.local. Ensure you are using the Live key (not Test, unless intended). Restart the dev server (npm run dev) after changing .env.local. Verify the key is correct in the MessageBird dashboard.

• Environment Variables Not Loaded:

  • Symptom: API route returns 500 error. Terminal logs show ""Server configuration error: Originator not set"" or similar related to process.env.
  • Solution: Ensure the file is named exactly .env.local (not .env or .env.development). Ensure variable names match (MESSAGEBIRD_ACCESS_KEY, MESSAGEBIRD_ORIGINATOR). Restart the dev server after creating/modifying the file.

• Invalid Recipient Number:

  • Symptom: API returns 500 error. Terminal logs show MessageBird error (e.g., code 10 - destination not reachable, or validation errors). Frontend might show success initially if the API call itself succeeded but delivery failed later.
  • Solution: Ensure the recipient number is in full E.164 format (e.g., +1..., +44...). Check the MessageBird Message Logs for specific delivery failure reasons. Implement server-side phone number validation.

• Invalid Originator:

  • Symptom: API returns 500 error. Terminal logs show MessageBird error (e.g., code 9 - invalid originator).
  • Solution: Verify MESSAGEBIRD_ORIGINATOR in .env.local. Ensure the number is owned/verified in your MessageBird account, or the Alphanumeric Sender ID is registered and allowed in the destination country.

• Alphanumeric Sender ID Restrictions:

  • Symptom: Messages not delivered or originator is replaced, especially in countries like the US/Canada.
  • Solution: Use a purchased virtual mobile number as the originator for these countries. Check MessageBird's country restriction documentation.

• MessageBird API Downtime/Errors:

  • Symptom: Intermittent 500 errors from your API route, potentially with specific MessageBird error codes related to temporary issues.
  • Solution: Implement robust logging to track these. Consider implementing retries with exponential backoff only for specific, transient error codes if necessary. Check MessageBird's status page.

• Development Server Restart: Remember to restart your Next.js development server (npm run dev) after making changes to .env.local or installing new dependencies.

9. Deployment

Deploying your Next.js application with MessageBird integration is straightforward.

Using Vercel (Recommended for Next.js):

1. Push to Git: Ensure your code (excluding .env.local and node_modules/) is pushed to a Git provider (GitHub, GitLab, Bitbucket).
2. Import Project: Log in to Vercel and import the Git repository. Vercel will typically auto-detect it as a Next.js project.
3. Configure Environment Variables: This is crucial. In your Vercel project settings, navigate to "Settings" > "Environment Variables". Add the following:
   • MESSAGEBIRD_ACCESS_KEY: Your Live API key.
   • MESSAGEBIRD_ORIGINATOR: Your chosen sender ID/number.
   • Ensure these variables are available to the "Production" environment (and optionally "Preview" and "Development" if needed). Do not mark them as "Exposed to Browser".
4. Deploy: Trigger a deployment (usually automatic on push to the main branch).

Other Platforms (Netlify, AWS Amplify, Docker, Node Server):

• The process is similar: build your Next.js application (npm run build) and deploy the output (.next directory, public, package.json, etc.).
• The key difference is how you manage environment variables. Consult your platform's documentation for securely setting server-side environment variables for MESSAGEBIRD_ACCESS_KEY and MESSAGEBIRD_ORIGINATOR. Never bundle .env.local in your deployment artifact.

10. Verification and Testing Checklist

After deployment (or during development), perform these checks:

• • Form Submission: Can you successfully enter a recipient number and message and click ""Send SMS""?
• • Frontend Feedback (Success): Does the form show a success message after a successful send attempt?
• • Frontend Feedback (Error): Does the form show an appropriate error message if you enter invalid data (e.g., missing recipient) or if the API call fails?
• • SMS Reception: Does the test message arrive on the recipient's phone?
• • Originator Check: Does the received SMS show the correct originator (your configured number or sender ID)?
• • API Route Logs (Server/Deployment Platform): Can you access server logs to confirm the API route is being hit and see the MessageBird success/error logs?
• • MessageBird Message Logs: Does the sent message appear correctly in the MessageBird dashboard message logs with a sent or delivered status? Check for failed status and reasons.
• • Environment Variables: Confirm environment variables are correctly configured in the deployment environment (Vercel settings, etc.) and not exposed to the browser.
• • Basic Input Validation Test: Try sending without a recipient or message – does the API return a 400 Bad Request?
• • Security Check: Ensure .env.local is not in your Git repository.

Next Steps and Further Enhancements

This guide covers the basics. You can extend this implementation by:

• Adding robust input validation using libraries like libphonenumber-js for phone numbers.
• Implementing authentication to protect the sending functionality so only logged-in users can access it.
• Building a UI for message history by querying MessageBird logs via their API or storing sent message details in your own database.
• Handling inbound messages by setting up webhooks in MessageBird to receive replies or incoming messages to your virtual number.
• Scheduling messages using a database and a background job runner (like BullMQ with Redis, or a serverless scheduler like Vercel Cron Jobs) to send messages at a future time.
• Adding templates for creating reusable message templates for common notifications.

This guide provides a solid foundation for integrating MessageBird SMS capabilities into your Next.js projects securely and effectively. Remember to prioritize security, especially around API key management and input validation. Happy coding!