Set up Sinch SMS delivery reports by creating a webhook endpoint in your application. This endpoint receives real-time status updates from Sinch about your sent messages. The setup involves configuring your Sinch account, setting up a web server to handle incoming requests, and implementing logic to process the delivery reports. Use a tool like ngrok to expose your local development server for testing callbacks.

A Sinch SMS Delivery Report (DLR) is a real-time notification from Sinch that provides the status of your sent SMS messages. These reports are delivered to a webhook URL you specify, allowing your application to track message delivery status like "Delivered", "Failed", or "Pending". DLRs are crucial for applications needing reliable communication and status monitoring.

Fastify is a high-performance web framework for Node.js, chosen for its speed, extensibility, and developer-friendly features. Its efficiency makes it ideal for handling real-time callbacks like Sinch DLRs, ensuring quick responses and minimal overhead. Fastify's plugin system also simplifies adding features like authentication and rate limiting.

Test Sinch DLR webhooks locally using ngrok, which creates a public URL that tunnels requests to your local server. After starting ngrok, update your .env file's CALLBACK_BASE_URL with your ngrok HTTPS URL. Then, start your Fastify server and send a test SMS using the provided /send-test-sms endpoint. Observe your server logs and the ngrok interface to verify successful callback processing.

Prisma is a next-generation ORM (Object-Relational Mapper) used for database schema management and interactions. In this Sinch DLR setup, Prisma simplifies database operations by defining a schema for storing message statuses, generating migrations, and providing a clean API for querying and updating data. It streamlines database interaction in your Node.js application.

The provided code includes a /send-test-sms route in server.js. Access it via a GET request with query parameters for 'to', 'from' (optional), and 'body' (optional). It uses your Sinch API credentials and ngrok URL to send an SMS configured to trigger delivery report callbacks to your webhook endpoint. Remember to update your environment variables before running.

Use 'per_recipient' delivery reports when you require real-time status updates for each individual recipient of your SMS messages. This setting, configured in the Sinch API request payload, ensures that your webhook receives a callback for every status change for each recipient. This is ideal for applications requiring granular tracking of delivery outcomes.

The database schema, defined in prisma/schema.prisma, includes a MessageStatus model to store the status updates. It stores batchId, recipient, status, statusCode, timestamps, and an optional clientReference. A unique constraint is defined on batchId and recipient to enable efficient upsert operations. This constraint is important to ensure that each message recipient has only one record in the database.

Yes, you can use SQLite for the Sinch DLR project, especially for simplified local development. During Prisma initialization, choose SQLite as the datasource provider and update the DATABASE_URL in your .env file accordingly. The code adapts to either PostgreSQL (used in the example) or SQLite based on this environment variable.

Secure your Sinch DLR webhook ideally with signature verification, if available, by checking a Sinch-generated signature against your shared secret. If not available, use Basic Authentication by configuring credentials in your Sinch Dashboard and adding authentication checks in your webhook endpoint. Always use HTTPS and consider rate limiting to prevent abuse.

Sinch requires an immediate 200 OK response to acknowledge receipt of the delivery report callback. This confirms to Sinch that your endpoint received the data. Processing the DLR payload should happen asynchronously after sending the 200 OK to prevent Sinch from retrying the callback unnecessarily if processing takes time.

Handle Sinch DLR errors by implementing robust error handling and logging within your processDeliveryReport function. Log errors during validation, database interactions, or timestamp parsing. For critical failures, consider a dead-letter queue (DLQ) to store failed payloads for later inspection or retry. Monitor your logs and endpoint health.

ngrok creates a secure tunnel from a public URL to your local development server. It's essential for testing Sinch webhooks locally, as it allows Sinch to send callbacks to your server even though it's not publicly accessible. Update your .env file with the ngrok HTTPS URL and restart your server after starting ngrok.

Install the required dependencies for the Sinch DLR project using npm or yarn. The main dependencies include fastify, dotenv, axios, and @prisma/client. For Prisma setup, install the Prisma CLI as a development dependency using npm install -D prisma. Ensure your .env file is configured with your database and Sinch credentials before running.