I use Magento 2.In Magento 2 Api are present.
How to use postman for a request like GET /V1/modules.
First you need to set up a user to get the authorization key. This tutorial walks you through that process. Once you have that, you can set up postman with these settings:
Where your GET request will have your URL (local or what not), and the
Bearer will have your Access Token from the user you set up.
Also, you can test this out and get some information about the API from Swagger, the built in API UI. Every 2.2 install has access with this URL:
You can place the same Access Token in
api_key box and get access to all the APIs in the system (without the key you will only see public API endpoints).
You can also import all magento endpoints, just follow this article