top of page
  • Writer's pictureEdgar Silva

Harness the Power of Optic: Generating OpenAPI Through API Traffic


In today's digital world, APIs (Application Programming Interfaces) have become the building blocks of modern applications, driving digital transformation by connecting different systems, platforms, and applications. As the number of APIs increases, so does the complexity of maintaining them. Documenting and keeping track of APIs can become a daunting task, even more so when these APIs are updated frequently. This is where OpenAPI and tools like Optic come into play.

What is OpenAPI?

OpenAPI is a specification for building APIs that offer some great benefits. It enables developers and software architects to design, build, document, and manage APIs - providing a standard and language-agnostic interface to RESTful APIs. OpenAPI helps to accelerate development, improve API quality, and enhance the usability and adoption of APIs.

However, creating and maintaining an OpenAPI document can be a time-consuming and error-prone task, especially when you have to update it manually every time your API changes.

Benefits of Using Optic

  1. Saves Time: With Optic, you no longer have to manually update your API specifications. It automatically syncs your API and its documentation, saving you precious development time.

  2. Improves Accuracy: By monitoring your API traffic, Optic reduces the chances of human error that come with manual updates, ensuring that your API documentation is always accurate.

  3. Facilitates Collaboration: Optic makes it easier to collaborate on API development. With the automatic generation of up-to-date API specs, team members can easily understand the current state of the API and collaborate more effectively.

  4. Enhances Developer Experience: With an up-to-date and accurate OpenAPI specification, developers can quickly understand how to use your API, enhancing their overall experience.

Setting up Optic

Before we dive in, you'll need to install Optic. Make sure you have Node.js installed on your system as Optic requires it. You can install Optic globally by using the npm package manager as follows:

npm install -g @useoptic/cli

Initializing Optic on Your Project

Once installed, you need to initialize Optic in your API project. Navigate to your project's directory and run:

api init

This will set up Optic in your project, creating an optic.yml configuration file where you can define your API setup and tasks.

Setting Up Your API Task

In the optic.yml file, define the tasks for your API. A task represents a certain state of your API, such as running your tests or running your API in development.

Here's an example of setting up a task for a Node.js API that runs on localhost and port 3000:

tasks:my_api:command: npm startinboundUrl: http://localhost:3000

In this example, my_api is the name of the task, command is the command to start your API, and inboundUrl is the URL where your API is running.

Starting Optic with Your API

To start your API with Optic, you can use the api start command followed by your task's name:

api start my_api

Now, Optic is observing your API traffic, watching for any changes in the API behavior.

Making Changes and Reviewing Them with Optic

Let's say you've added a new endpoint or modified an existing one. When you use your API or run your tests, Optic will observe these changes and suggest updates to your API specification.

To view these changes, you can open your browser's Optic dashboard, typically at http://localhost:34444.

In the dashboard, you'll see a list of endpoints. Optic will flag any observed changes in your API behavior, allowing you to review, document and approve them. Once you're happy with the changes, click the "Approve" button, and Optic will update your OpenAPI spec.


In a rapidly changing digital landscape, having a tool like Optic to automate the tedious task of maintaining your API specifications is invaluable. It improves efficiency and ensures your API documentation is accurate and up-to-date, enhancing collaboration and boosting the overall developer experience. So, whether you're an API veteran or just starting with API development, Optic is a tool worth exploring.

For more information check it out:

4 views0 comments

Recent Posts

See All


bottom of page