REST Assured: how do I POST JSON and assert the response?

Question

Basic pattern for a POST /users with a JSON body and status + body assertions.

Sam Okafor · Accepted Answer

Set the content type, pass a body (POJO, Map or raw string) and assert on the response.

```java
Order order = new Order("SKU-42", 2);

given()
  .contentType(ContentType.JSON)
  .header("Authorization", "Bearer " + token)
  .body(order)                    // serialised by Jackson/Gson on the classpath
.when()
  .post("/api/orders")
.then()
  .statusCode(201)
  .body("id", notNullValue())
  .body("items[0].sku", equalTo("SKU-42"))
  .time(lessThan(2000L));
```

Common gotchas: without `contentType(JSON)` the server sees `text/plain` and returns 415. Serialization needs Jackson or Gson on the classpath — otherwise pass a raw JSON string or a `Map`. For contract-level confidence add `.body(matchesJsonSchemaInClasspath("order-schema.json"))` so a renamed field fails the test instead of silently returning null.

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

given()
  .contentType(ContentType.JSON)
  .body(Map.of("email", "a@b.com", "role", "qa"))
.when()
  .post("/users")
.then()
  .statusCode(201)
  .body("id", notNullValue())
  .body("email", equalTo("a@b.com"));

REST Assured: how do I POST JSON and assert the response?

1 answer