Single endpoint architecture in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Single Endpoint Architecture in GraphQL?

It means using one URL endpoint to handle all client requests instead of multiple URLs. This single endpoint processes queries and returns exactly the data requested.

beginner

Why does GraphQL use a single endpoint instead of multiple endpoints like REST?

Because GraphQL lets clients specify exactly what data they want in one request, so one endpoint can handle many types of queries and mutations efficiently.

intermediate

How does a single endpoint improve client-server communication?

It reduces the number of requests clients make, avoids over-fetching or under-fetching data, and simplifies API management by centralizing data access.

intermediate

What role does the GraphQL schema play in single endpoint architecture?

The schema defines all possible queries and mutations the single endpoint can handle, guiding how data is fetched and shaped for clients.

advanced

Can a single endpoint architecture handle complex data requirements? How?

Yes, by allowing clients to request nested and related data in one query, the single endpoint can return complex, tailored responses efficiently.

What does the single endpoint in GraphQL typically represent?

A One URL that handles all queries and mutations

B Multiple URLs for different data types

C A database connection string

D A client-side library

GraphQL uses one URL endpoint to process all client requests, unlike REST which uses multiple URLs.

Which of the following is a benefit of single endpoint architecture?

A It requires multiple endpoints to manage

B Clients must make multiple requests for different data

C It increases over-fetching of data

D Clients can request only the data they need

Single endpoint lets clients specify exactly what data they want, reducing unnecessary data transfer.

In GraphQL, what defines the structure of data available through the single endpoint?

A Client-side code

B REST API documentation

C GraphQL schema

D Database tables

The GraphQL schema defines all queries and mutations the endpoint can handle.

How does single endpoint architecture affect API versioning?

A It requires a new endpoint for each version

B It simplifies versioning by evolving the schema without changing the endpoint URL

C It prevents any changes to the API

D It duplicates endpoints for backward compatibility

GraphQL allows schema evolution at the single endpoint, avoiding multiple versioned URLs.

Which statement about single endpoint architecture is FALSE?

A It requires clients to know multiple URLs

B It can handle nested and related data in one request

C It reduces the number of network requests

D It centralizes data fetching logic

Clients only need to know one URL in single endpoint architecture, not multiple.

Explain how single endpoint architecture works in GraphQL and why it is beneficial compared to multiple endpoints.

Think about how clients ask for data and how the server responds.

Describe the role of the GraphQL schema in supporting single endpoint architecture.

Consider what tells the server what data can be requested.

Practice

1. What is the main advantage of using a single endpoint architecture in GraphQL?

easy

A. It increases the complexity of client requests.

B. It requires multiple URLs for different data types.

C. It limits the flexibility of data fetching.

D. It allows all data queries to be sent to one URL.

Solution

1. Step 1: Understand the concept of single endpoint

   Single endpoint architecture means all queries go through one URL.

2. Step 2: Compare options with this concept

   Only It allows all data queries to be sent to one URL. states this clearly; others contradict the concept.

3. Final Answer:

   It allows all data queries to be sent to one URL. -> Option D

4. Quick Check:

   Single endpoint = one URL [OK]

Hint: Single endpoint means one URL for all queries [OK]

Common Mistakes:

• Thinking multiple URLs are needed
• Confusing flexibility with complexity
• Assuming single endpoint limits data fetching

2. Which of the following is the correct way to define a GraphQL endpoint URL for single endpoint architecture?

easy

A. /api/users, /api/posts

B. /data/users

C. /graphql

D. /api/v1/data

Solution

1. Step 1: Identify typical single endpoint URL

   GraphQL commonly uses a single endpoint like '/graphql' for all queries.

2. Step 2: Check other options

   Options A, C, and D suggest multiple or REST-style URLs, not single endpoint.

3. Final Answer:

   /graphql -> Option C

4. Quick Check:

   Single endpoint URL = /graphql [OK]

Hint: Single endpoint usually named '/graphql' [OK]

Common Mistakes:

• Choosing multiple URLs instead of one
• Confusing REST endpoints with GraphQL
• Ignoring standard naming conventions

3. Given the GraphQL query sent to a single endpoint /graphql:

{ user(id: "1") { name email } }

What will the server return?

medium

A. 404 Not Found

B. { "data": { "user": { "name": "Alice", "email": "[e-mail]" } } }

C. { "error": "Multiple endpoints required" }

D. { "data": { "users": [] } }

Solution

1. Step 1: Understand the query and endpoint

   The query requests user data by id from the single endpoint '/graphql'.

2. Step 2: Predict server response

   The server returns the requested user data in JSON format under 'data'. { "data": { "user": { "name": "Alice", "email": "[e-mail]" } } } matches this.

3. Final Answer:

   { "data": { "user": { "name": "Alice", "email": "[e-mail]" } } } -> Option B

4. Quick Check:

   Query returns requested user data [OK]

Hint: Single endpoint returns data in 'data' field JSON [OK]

Common Mistakes:

• Expecting HTTP 404 for valid query
• Thinking multiple endpoints needed
• Confusing error format with data response

4. A developer tries to send two different queries to separate URLs /api/users and /api/posts but gets errors. What is the likely problem in a GraphQL single endpoint setup?

medium

A. GraphQL requires all queries to go through a single endpoint URL.

B. The URLs are correct; the error is due to query syntax.

C. Multiple endpoints are allowed; the server is down.

D. The client must send queries via GET, not POST.

Solution

1. Step 1: Identify the architecture requirement

   GraphQL single endpoint architecture requires all queries to use one URL.

2. Step 2: Analyze the error cause

   Using multiple URLs breaks this rule, causing errors. GraphQL requires all queries to go through a single endpoint URL. explains this correctly.

3. Final Answer:

   GraphQL requires all queries to go through a single endpoint URL. -> Option A

4. Quick Check:

   Single endpoint means one URL [OK]

Hint: All GraphQL queries use one URL [OK]

Common Mistakes:

• Assuming multiple endpoints are allowed
• Blaming query syntax without checking URL
• Confusing HTTP methods with endpoint issues

5. How does single endpoint architecture improve backend management in a GraphQL API?

hard

A. It centralizes all data fetching through one URL, simplifying routing and security.

B. It requires separate servers for each data type, increasing complexity.

C. It forces clients to send multiple requests to different URLs.

D. It limits the types of queries clients can make.

Solution

1. Step 1: Understand backend management benefits

   Single endpoint centralizes requests, making routing and security easier to manage.

2. Step 2: Evaluate options

   It centralizes all data fetching through one URL, simplifying routing and security. correctly states this benefit; others describe drawbacks or incorrect facts.

3. Final Answer:

   It centralizes all data fetching through one URL, simplifying routing and security. -> Option A

4. Quick Check:

   Centralized endpoint = simpler backend [OK]

Hint: One URL centralizes backend tasks [OK]

Common Mistakes:

• Thinking multiple servers are needed
• Believing clients must send many requests
• Assuming query types are limited