How to Migrate a Postman Collection to Rest Assured (Java)

2026-07-17 · By Avinash Kamble, reviewed by Priyanka G.

Postman is great for exploration. It falls short when you need Maven-managed API tests inside a CI pipeline. Here's the clean migration path — and how to skip 90% of the typing with the free Postman → Code Converter.

In Postman: Collection → three dots → Export → Collection v2.1. Save the JSON.

Paste the JSON into the converter, pick "Rest Assured (Java)". It emits one class per folder, JUnit 5 methods, and translates pm.test assertions into then().body(...).

<dependency>
  <groupId>io.rest-assured</groupId>
  <artifactId>rest-assured</artifactId>
  <version>5.4.0</version>
  <scope>test</scope>
</dependency>
<dependency>
  <groupId>org.junit.jupiter</groupId>
  <artifactId>junit-jupiter</artifactId>
  <version>5.11.0</version>
  <scope>test</scope>
</dependency>

Postman                             Rest Assured
pm.response.to.have.status(200)     .statusCode(200)
pm.expect(json.name).to.eql('X')    .body("name", equalTo("X"))
pm.expect(json.items).to.have.length(3)  .body("items.size()", is(3))
pm.expect(json.total).to.be.above(0)     .body("total", greaterThan(0))

Postman env variables become System.getProperty("baseUrl"). Configure per-environment Maven profiles for dev / staging / prod.

mvn -Denv=staging test

Add the step to GitHub Actions and API regressions fail PR checks automatically.