? GraphQL API Testing in Postman

? Quick Overview

GraphQL API testing in Postman allows you to validate queries and mutations by sending structured requests to a single endpoint. Unlike REST, GraphQL uses a flexible query language where clients request exactly the data they need.

? Key Concepts

• Query – Used to fetch data from the GraphQL server
• Mutation – Used to create, update, or delete data
• Single Endpoint – All operations go through one URL
• Schema – Defines types, queries, and mutations

? Syntax / Theory

In Postman, GraphQL requests are usually sent as HTTP POST requests with a JSON body. The body contains a query field and optional variables.

// Basic GraphQL request structure
{
"query": "query { users { id name email } }"
}

? Code Example(s)

? GraphQL Query Example

// Fetching user list using GraphQL query
query {
users {
id
name
email
}
}

? GraphQL Mutation Example

// Creating a new user using GraphQL mutation
mutation {
createUser(name: "Rahul", email: "rahul@test.com") {
id
name
email
}
}

? Live Output / Explanation

? Interactive Example

Try switching between query and mutation tabs inside Postman’s GraphQL editor. You can also use Postman’s built-in schema explorer to auto-generate queries.

// Example of GraphQL variables in Postman
{
"query": "query GetUser($id: ID!) { user(id: $id) { name email } }",
"variables": { "id": "1" }
}

? Use Cases

• Testing frontend data requirements precisely
• Validating backend schema changes
• Automating API tests with Postman collections
• Debugging complex nested data responses

? Interactive Postman UI Simulator