</>

Technology

Rest Assured

Difficulty

Advanced

Experience

3-5 Years

Type

Technical

AutomateQA Team

QA Automation Engineers

June 19, 2026

Interview Question

What is JSON Schema and how do you validate it with Rest Assured?

Q: What is JSON Schema and how do you validate it with Rest Assured?

JSON Schema Validation with Rest Assured What is Schema? A Schema is a JSON file that contains only datatype information and expected keys of the JSON. There are no values present in the schema. JSON Schema is a JSON media type for defining the structure of JSON data. It provides a contract for: - What JSON data is required for a given application - How to interact with it - Defines validation, documentation, and hyperlink navigation Why JSON Schema Validation? JSON Schema Validation is required to monitor API responses and ensure that the format we are getting is the same as the expected one.

Answer

JSON Schema Validation with Rest Assured

What is Schema?

A Schema is a JSON file that contains only datatype information and expected keys of the JSON. There are no values present in the schema.

JSON Schema is a JSON media type for defining the structure of JSON data. It provides a contract for:

✓What JSON data is required for a given application
✓How to interact with it
✓Defines validation, documentation, and hyperlink navigation

Why JSON Schema Validation?

JSON Schema Validation is required to monitor API responses and ensure that the format we are getting is the same as the expected one. It catches structural issues like:

✓Missing required fields
✓Wrong data types (e.g., integer returned instead of string)
✓Extra unexpected fields

How to Automate Schema Validation

Step 1: Add Dependencies to pom.xml

XML

<dependency>
    <groupId>io.rest-assured</groupId>
    <artifactId>json-schema-validator</artifactId>
    <version>5.3.0</version>
</dependency>
<dependency>
    <groupId>org.hamcrest</groupId>
    <artifactId>hamcrest-all</artifactId>
    <version>1.3</version>
</dependency>

Step 2: Create the JSON Schema File

Create src/test/resources/JsonSchema.json:

JSON

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "data": {
      "type": "object",
      "properties": {
        "id": { "type": "integer" },
        "email": { "type": "string" },
        "first_name": { "type": "string" },
        "last_name": { "type": "string" }
      },
      "required": ["id", "email", "first_name", "last_name"]
    }
  },
  "required": ["data"]
}

Step 3: Validate Using matchesJsonSchema

Java

import static io.restassured.module.jsv.JsonSchemaValidator.*;

@Test
public void givenUrl_validateSchema() throws FileNotFoundException, IOException {

    File schema = new File(System.getProperty("user.dir") + "/JsonSchema.json");

    RestAssured.given()
               .get("https://reqres.in/api/users/2")
               .then()
               .body(matchesJsonSchema(schema));
}

Common Schema Validation Errors

Error	What It Means
`object has missing required properties`	API response is missing a field defined as required in schema
`instance type (integer) does not match any allowed primitive type (allowed: ["string"])`	Wrong data type returned

Manual Schema Comparison

To compare schemas manually, use jsonschema2pojo or paste both JSONs into: http://www.jsondiff.com/