Webhook

What is a Webhook?

A webhook is essentially an HTTP request that fires off when something happens in one system, delivering a data payload to another system. Jeff Lindsay coined the term back in 2007, borrowing from the programming concept of a "hook." At its core, webhooks are user-defined HTTP callbacks that let applications talk to each other automatically and in real-time, enabling powerful workflow automation capabilities.

You might hear webhooks called "reverse APIs" or "push APIs," and there's a good reason for that. They flip the traditional communication model on its head. Rather than having a client pester the server over and over asking "any updates yet?", the server just sends out a single HTTP POST request the moment something relevant happens. This event-driven approach gets rid of the wasteful back-and-forth of polling and makes true real-time communication between systems possible.

Setting up a webhook is fairly straightforward. The client gives the source application a unique URL and tells it which events to watch for. After that, the webhook runs on autopilot. When the specified event fires in the source system, it shoots an HTTP POST request to that URL with a payload of relevant data, usually formatted as JSON. The receiving application can then react right away without having to keep checking in. Proper process documentation helps teams understand how their webhooks fit into broader business processes.

Key Characteristics of Webhooks

• Event-Driven Architecture: Webhooks fire based on specific triggers in the source application, whether that's a user signing up, a payment going through, or code getting committed. Data only gets sent when something actually happens.
• Real-Time Data Delivery: Unlike APIs that need to be polled at intervals, webhooks push data the instant events occur. No waiting around, no delays from request-response cycles.
• HTTP-Based Communication: Webhooks rely on standard HTTP POST requests, which makes them work across basically any platform or programming language without needing special protocols.
• JSON Payload Format: The event data typically comes packaged as JSON, giving you a standardized, machine-readable format for transmitting what happened and any relevant details.
• Unidirectional Data Flow: Webhooks send information from source to destination in one direction, though the receiving application can always use APIs to respond or acknowledge if needed.

Webhook Examples

Example 1: GitHub to CI/CD Pipeline Integration

Say a developer pushes code to a GitHub repository. A webhook immediately pings a CI/CD platform like Jenkins or CircleCI with details about the commit, the branch, and which files changed. This kicks off the pipeline to build the app, run tests, and deploy to staging or production assuming everything passes. Without webhooks, the CI/CD system would have to check GitHub every few minutes looking for new commits, wasting both time and resources.

Example 2: Payment Processing Automation

When someone completes a purchase, payment gateways like Stripe or PayPal fire off a webhook to the e-commerce platform. The payload includes transaction details: payment status, amount, customer info, order ID. The receiving system can immediately verify the payment, flip the order to "Paid," kick off fulfillment, send confirmation emails, and update inventory. Because this happens in real-time, customers get instant confirmation and orders start processing without any lag.

Webhook vs API

Webhooks and APIs are complementary technologies that often work hand in hand, but they solve different problems when it comes to connecting applications.

How Glitter AI Helps with Webhooks

Glitter AI tackles one of the trickier problems with webhooks: keeping them documented and understandable. Webhooks can create powerful automations between systems, but they tend to become invisible plumbing that only the person who set them up really understands. When that person moves on or forgets the details, webhook configurations turn into mysterious black boxes. That leads to maintenance headaches and integration failures down the road.

With Glitter's screen recording and AI-powered documentation features, teams can capture the whole webhook setup process, from configuration screens to payload formats to testing steps. Glitter automatically creates comprehensive guides showing which webhooks exist, what events trigger them, what data they carry, and how receiving systems handle that data. This kind of documentation proves invaluable when you're onboarding new developers, debugging integration problems, auditing system connections, or migrating to new platforms. By making webhook integrations visible and understandable, Glitter keeps these critical automations as maintainable, transferable knowledge instead of letting them become technical debt.