From Postman to IntelliJ IDEA REST Client: Features, Usage, and Scripting

API debugging is an essential skill for software developers, and while Postman has long been a popular REST client, IntelliJ IDEA REST Client offers all of Postman's capabilities plus additional features that streamline development and testing.

Why switch from Postman to IDEA REST Client?

IDEA REST Client includes every function of Postman, such as a REST console and request history.

It allows developers to stay within a single IDE, eliminating the need to switch tools.

The client supports environment configuration, response assertions, and scriptable processing.

Request configurations can be stored in files, enabling easy sharing among project members.

IDEA REST Client Console

Access the console via Tools → HTTP Client → Test RESTFUL Web Service . The interface provides request method selection, parameter entry, and header configuration, similar to Postman. For Basic Authorization, a button opens a dialog to input credentials, which are then added to the header automatically.

History Request Records

IDEA saves the last 50 requests in .idea/httpRequests/http-requests-log.http . The log can be opened to re‑run previous requests by clicking the run icon, and new entries are added to the top of the file.

Building HTTP Request Scripts

Requests can be written in .http or .rest files. Each request is separated by ### . Example syntax:

### Demonstration POST request
POST {{baseUrl}}/get?show_env=1
Accept: application/json

{
   "name":"a"
}
### Demonstration GET request

GET {{baseUrl}}/post
Content-Type: application/x-www-form-urlencoded

id=999&value=content

Parameters and headers must be placed on separate lines, and line breaks separate request bodies from the request line.

Environment Configuration

Create a http-client.private.env.json file alongside the script to define environments (e.g., dev , uat ) and variables such as baseUrl . Placeholders like {{baseUrl}} are replaced at runtime, allowing the same script to run against different environments.

Result Assertions

IDEA REST Client supports scriptable assertions. Example:

### Successful test: check response status is 200
GET https://httpbin.org/status/200

> {%
client.test("Request executed successfully", function() {
  client.assert(response.status === 200, "Response status is not 200");
});
%}

Storing Result Values

Tokens or other values can be saved to global variables for later use:

### Demonstration POST request
POST https://httpbin.org/post
Content-Type: application/json

{
  "user": "admin",
  "password": "123456"
}
> {% client.global.set("auth_token", response.body.json.token); %}
### Demonstration GET request

GET https://httpbin.org/headers
Authorization: Bearer {{auth_token}}

After the authentication request, the token is stored globally and automatically injected into subsequent requests.

Conclusion

While Postman remains a solid tool, IDEA REST Client integrates API testing directly into the IDE, offering shared request files, environment handling, scripting, and assertions that make it a compelling alternative for backend developers.