First-run commands per functional tool

The default path (Postman + newman) stays in the SKILL.md spine. Below are the shortest paths to one passing test for the other functional options. Point the base URL at a locally running service or a staging instance, never production.

REST Assured (Java)

Add the dependency, pinned to the current io.rest-assured:rest-assured release (rest-assured.io):

<dependency>
    <groupId>io.rest-assured</groupId>
    <artifactId>rest-assured</artifactId>
    <version>6.0.1</version>
    <scope>test</scope>
</dependency>

The usage guide recommends statically importing io.restassured.RestAssured.*, io.restassured.matcher.RestAssuredMatchers.*, and org.hamcrest.Matchers.*, and writing assertions as given() / when() / then() with statusCode(...) plus a body(...) matcher (rest-assured wiki):

import static io.restassured.RestAssured.*;
import static org.hamcrest.Matchers.*;

@Test
public void returns_200_with_id() {
    given()
        .baseUri(System.getenv("API_BASE_URL"))
    .when()
        .get("/items/1")
    .then()
        .statusCode(200)
        .body("id", equalTo(1));
}

Success looks like: mvn test reports the test as passing. Verify it can fail by asserting equalTo(2).

Karate (JVM, feature files)

Add io.karatelabs:karate-junit5 as a test dependency, pinned to a release listed on the repository, and write a .feature file. match is the assertion keyword, and #number / #string are type placeholders so the test does not bind to volatile values (github.com/karatelabs/karate, docs.karatelabs.io):

Feature: Items API

  Scenario: Get an item
    Given url baseUrl
    And path 'items/1'
    When method GET
    Then status 200
    And match response == { id: '#number', name: '#string' }

Success looks like: mvn test passes and an HTML report appears under target/karate-reports/.

Tavern (Python, pytest)

Install, then write one YAML file (github.com/taverntesting/tavern):

pip install tavern[pytest]

test_name: GET /items/1 returns 200 with expected id

stages:
  - name: fetch item
    request:
      url: "{host}/items/1"
      method: GET
    response:
      status_code: 200
      json:
        id: 1

Run it with py.test test_items.tavern.yaml -v, or without pytest via tavern-ci --stdout test_items.tavern.yaml (tavern.readthedocs.io).

Success looks like: pytest reports 1 passed. Verify it can fail by changing the expected id.

Schemathesis (schema-driven, no test authoring)

There is nothing to author. uvx runs it without installing; uv pip install makes it permanent. Both forms and the schemathesis run <schema-url> command are from the README (github.com/schemathesis/schemathesis):

uvx schemathesis run https://your-api.example.com/openapi.json
# or: uv pip install schemathesis && schemathesis run <schema-url>

Success looks like: a per-endpoint summary with no failures. A failure prints the generated request that broke conformance, so treat the first run as a discovery pass rather than a gate.

RESTler (stateful fuzzing, later)

RESTler needs Python 3.12.8 and .NET 8.0, and runs as four stages: compile a grammar from the spec, test (a smoke pass measuring coverage), fuzz-lean (one pass per endpoint with default checkers), then fuzz (breadth-first deep exploration) (github.com/microsoft/restler-fuzzer). The setup cost is real, so reach for it only after a functional suite exists and the API is a genuine resource lifecycle.