GraphQL

GraphQL is a query language for APIs that gives clients the power to ask for exactly what they need.

Overview

Making a Query

1. Select GraphQL from the protocol dropdown
2. Enter the GraphQL endpoint: https://api.example.com/graphql
3. Write your query in the editor
4. Click Run

Query Editor

The query editor provides:

• Syntax highlighting for GraphQL
• Auto-indentation
• Error highlighting

Basic Query

query {
  users {
    id
    name
    email
  }
}

Query with Variables

query GetUser($id: ID!) {
  user(id: $id) {
    id
    name
    email
    posts {
      title
    }
  }
}

Variables (JSON):

{
  "id": "123"
}

Mutation

mutation CreateUser($input: CreateUserInput!) {
  createUser(input: $input) {
    id
    name
    email
  }
}

Variables:

{
  "input": {
    "name": "John Doe",
    "email": "[email protected]"
  }
}

Request Configuration

Headers

Add authentication and custom headers:

Header	Value
Authorization	Bearer {{TOKEN}}
X-API-Key	{{API_KEY}}

Variables

The Variables tab accepts JSON that maps to your query's variables:

{
  "id": "user-123",
  "limit": 10,
  "filter": {
    "status": "active"
  }
}

Operation Name

When your query contains multiple operations, specify which one to execute:

query GetUsers {
  users { id name }
}

query GetPosts {
  posts { id title }
}

Set Operation Name to GetUsers or GetPosts.

Response

The response shows:

• data: Query results
• errors: Any GraphQL errors (if present)
• Response time: Request duration

Successful Response

{
  "data": {
    "users": [
      { "id": "1", "name": "Alice" },
      { "id": "2", "name": "Bob" }
    ]
  }
}

Error Response

{
  "data": null,
  "errors": [
    {
      "message": "User not found",
      "path": ["user"],
      "locations": [{ "line": 2, "column": 3 }]
    }
  ]
}

Playground Example

Using the built-in GraphQL endpoint:

URL: http://localhost:19510/graphql

List Users

query {
  users {
    id
    name
    email
    createdAt
  }
}

Create User

mutation CreateUser($name: String!, $email: String!) {
  createUser(name: $name, email: $email) {
    id
    name
    email
  }
}

Variables:

{
  "name": "New User",
  "email": "[email protected]"
}

Get Single User

query GetUser($id: ID!) {
  user(id: $id) {
    id
    name
    email
  }
}

Variables:

{
  "id": "1"
}

Schema Introspection

Fetch the schema SDL from:

GET http://localhost:19510/graphql/sdl

Tips

Use Variables

Always use variables instead of string interpolation for dynamic values. This improves security and caching.

Fragments

Use fragments to reuse field selections:

fragment UserFields on User {
  id
  name
  email
}

query {
  users {
    ...UserFields
  }
}