Blog
Messaging
The 411
What is a Webhook?
Webhooks or HTTP Callback events are events that are sent to an application server or apps via HTTP to notify the user of activity related to the system they are connected to.
Webhooks connect to URLs to pull and store data whenever an event occurs. Unlike APIs, webhooks do not run simultaneously and will only run and pull data whenever these events occur. Webhooks are useful for creating workflows and automation, and are utilized by those who need to use minimal resources.
How do webhooks work?
Understanding how webhooks function requires a shift in thinking compared to traditional API requests. Let’s break it down:
Imagine you’re constantly asking a friend for updates. You might text them every hour: “Hey, any news?” They have to stop what they’re doing, check for updates, and text you back. That’s essentially how traditional APIs work. Your application polls the API, repeatedly asking for data. This can be inefficient and resource-intensive, especially if the information doesn’t change frequently.
Webhooks: The notification system
Webhooks, often referred to as reverse APIs, flip this model. Instead of you asking for updates, the service pushes the information to you when something happens. Think of it like subscribing to a notification service. When a specific event occurs (like a new message arriving or a payment being processed), the service sends a notification—a webhook–to a URL you’ve specified.
The step-by-step process:
- Subscription: Your application registers a URL (often called a “webhook endpoint”) with the service providing the webhook. This is like telling the service, “Send me notifications at this address.”
- Event trigger: Something happens within the service. This could be anything from a new SMS being received to a phone call completing.
- Data transmission: The service packages the relevant data about the event into an HTTP request (usually a POST request) and sends it to your registered webhook endpoint. This data is typically formatted as JSON or XML.
- Processing: Your application receives the webhook, parses the data, and takes appropriate action. This might involve updating a database, triggering another process, or sending a notification to a user.
Bandwidth and webhooks: Real-world applications
At Bandwidth, we leverage webhooks extensively to provide developers with real-time visibility and control over their communications. For example:
- Number ordering: The notification webhook API is used to notify customers of events and changes that occur with various feature and service orders that are being processed by the Bandwidth Numbers API on their behalf. In general, this notification webhook will be called whenever an order that is in-scope changes state.
- Message delivery status: Track the delivery status of SMS messages in real-time. Know immediately when a message has been delivered or failed.
- Call events: Receive notifications about call events like incoming calls, outgoing calls, call forwarding, and more if you’re using Bandwidth’s Voice API.
Key benefits of webhooks
- Real-time updates: Receive information as soon as it happens.
- Efficiency: Reduce the load on both your application and the service provider.
- Reduced latency: Faster response times compared to polling.
- Scalability: Easily handle large volumes of events.
Webhooks examples
Webhooks excel in scenarios requiring real-time, event-driven communication between systems. Instead of constantly checking for updates, applications using webhooks receive immediate notifications.
Common examples include:
- Real-time notifications: Receiving instant alerts when an event occurs, such as a payment processing, a file upload completing, or a new user signing up.
- Messaging status updates: Getting immediate confirmation on the delivery status (delivered, failed, received) of an SMS or MMS message as soon as the status changes. This is critical for applications built on platforms like Bandwidth’s Messaging API.
- Voice call events: Being instantly notified of call state changes like incoming calls, calls being answered, hang-ups, or call forwarding events, enabling dynamic call handling. This is a core function supported by Bandwidth’s Voice API.
- IoT data streaming: Sending data from devices or sensors as events occur, rather than the central server repeatedly polling each device.
- Version control system events: Triggering builds or deployments automatically when code is pushed to a repository.
How are webhooks different than APIs?
While both webhooks and APIs facilitate communication between applications, their approaches differ fundamentally.
When using APIs (Application Programming Interfaces) to request data, your application can make scheduled (polling) or on-demand API calls.
Webhooks, conversely, are event-driven. Instead of you asking, the service pushes data to your application when an event occurs. Think of it as a subscription–you define a URL (your webhook endpoint), and the service sends notifications there.
Essentially, APIs are about asking for information and creating a resource, while webhooks are about receiving information. Webhooks offer a more efficient and real-time solution for applications needing immediate updates. They complement APIs, often working together to provide a comprehensive integration strategy.
For instance, take messaging. There’s an API to create a new message (POST). From there, you could ask how the message is doing (GET) or leverage the webhook event sent when a status update has changed.
About Bandwidth’s webhooks
Bandwidth’s webhooks offer a powerful and flexible way to complement real-time communications applications, like helping you track your messaging metrics for the Bandwidth messaging API through webhooks. Here’s what sets them apart:
- Low latency: Receive event notifications almost instantly, crucial for responsive applications like interactive voice response (IVR) or real-time SMS marketing.
- Customizable events: Fine-tune the events you receive. Choose exactly what triggers a webhook notification, minimizing unnecessary data.
- Secure delivery: Built with security in mind, our webhooks utilize secure HTTPS connections to protect your data.
- Reliable infrastructure: Benefit from Bandwidth’s robust and scalable infrastructure, ensuring reliable webhook delivery.
- Simplified integration: Easy-to-use documentation and SDKs streamline the integration process, allowing you to focus on building your application.
- Deep telecom insights: Gain valuable insights into your communications traffic, enabling data-driven optimizations.
Bandwidth’s webhook translates into a powerful tool for building innovative and efficient communication solutions.
The information provided in this glossary definition does not, and is not intended to, constitute legal advice, nor does it necessarily represent Bandwidth's products or business practices. This page is for general informational purposes only.Related posts
Blog
Phone Numbers
Voice
VoIP Origination
How to get a VoIP Number
Blog
Messaging
RCS on iPhone vs Android: Beyond blue and green bubbles
