In today’s blog article, we show you how you can easily create your first API endpoint using webhooks and the automation tool n8n. We’ll take you through the individual parts of the workflow step by step, and you can test your own API in just a few minutes.

What is a webhook and why do we need it for our API?

For beginners venturing into creating an API endpoint (with n8n), an essential component to understand is a webhook. Picture a webhook as a busy postman, buzzing back and forth between applications, delivering real-time data. Their role is vital in the API creation world.

When you’re building your API endpoint with n8n, imagine utilizing a webhook as having someone who waits patiently. They’re looking out for specific instructions coming in as query parameters within a URL, just like a chef waiting for a dinner order. When these instructions arrive, the webhook springs into action, prompting the API to perform specific tasks based on the instructions received.

Thus, the major part of API crafting is understanding and employing webhooks correctly. With these, your API becomes capable of reacting to dynamic requests. In simpler terms, it’s like the API’s cooking up a different recipe each time based on the diner’s (user’s) preference. It’s about becoming a master of your kitchen, creating a responsive, interconnected, and user-controlled API environment.

Using n8n to build our API endpoint

Opting to use n8n, an automation software to build our API endpoint, makes the complex process of creating advanced automations, a breeze even for beginners. This is because n8n requires no deep coding knowledge, widening the door for everyone to participate.

One of n8n’s standout features is its easy-to-use workflow canvas. Imagine it like a digital drawing board that lets you sketch out and understand your workflows. You get to plan how your API behaves, in a simple, more visual and fun way.

Adding to its simplicity, n8n comes packed with many pre-built integrations. Think of these like ready-made building blocks, allowing you to add different features and functions to your API with ease, enabling you to build something uniquely suited to your needs.

In summary, using n8n to build our API endpoint with a webhook makes the task not only simpler but also sparks creativity, enabling everyone to create unique and personalized APIs.

To follow the following tutorial, you either need an n8n cloud account (n8n has a free trial period) or you can work with the open-source version that you run yourself on your computer.

Your first API endpoint

To make this tutorial as simple as possible, we use the n8n community and use one of the already created templates as our starting point.

n8n offers a large selection of different templates for automation, whether for IT, marketing or sales. If you are interested in something other than API creation, take a look around.

Here are a few examples:

• Gmail campaign sender: Bulk-send emails and follow up automatically if no reply
• Classify new bugs in Linear with OpenAI’s GPT-4 and move them to the right team
• Update HubSpot when a new invoice is registered in Stripe

Copying the “Creating an API endpoint” Template

Here you will find the template from which we will explain today how to define a simple API endpoint with n8n.

You can copy this template into your n8n workspace and then continue with the tutorial.

Webhook Listening

The first node, our trigger, is our starting point in the workflow. This node listens to incoming signals at the specified URL. Whenever someone accesses this URL, this workflow is started.

This node therefore ensures that we notice in our program when someone accesses our API endpoint so that we can then return the requested data.

You can make further adjustments at this point. For example, you can require users to authenticate themselves or adjust the type of HTTP requests for which the webhook is designed.

In our case, we can leave it at the basic settings of the template, so we do not require authentication and respond to GET requests.

API Logic

Now that we have defined when our API endpoint responds to requests using our webhook, we need to define a logic that leads to our output.

There are no limits to creativity here. For example, you can retrieve and return contact details from a database based on people’s names, or have an AI create a poem from the keywords provided by a user and play it out to your user.

For this tutorial, however, we will limit ourselves to an example with minimal complexity in order to explain only the functionality. With n8n you can extend this part with much more complex logic to build advanced API endpoints.

In this case, we use additional parameters that we receive from the GET request to construct the URL for a Google search.

You append additional parameters to a URL by adding e.g.

?first_name=bob&last_name=dylan

to the end of the respective URL of the webhook. We can then use these parameters in n8n in our workflow.

by controlling them as a formula as shown in the template (or image, see above). In this case, we get as output of this node directly the finished URL of the Google search, based on the first & last names that were specified as parameters in the GET request.

Webhook Response

Now that we have created this URL, we just need to send it back to our user as a webhook reponse.

Here, in addition to our Google Search Query, we add a little text to the response body that explains our answer. Just like in the previous step, we use the data from the previous nodes by referring to it with a formula inside of {{ }}.

Test Execution

If you now activate the workflow or execute it as a test, you only have to copy the url displayed in the webhook node into the search bar of your browser, append the required parameters and when you press enter you should get a response that looks like this one.

Congratulations, you have now defined your first API endpoint and it has processed its first request. Have fun developing the endpoint further and trying out the many other possibilities of n8n.