Media type versioning in Rest API - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the HTTP Content-Type header for version 2 of the API?

Given the following media type versioning scheme, what is the correct Content-Type header to request version 2 of the API?

application/vnd.example.api.v2+json

A application/vnd.example.api.v2+json

B application/vnd.example.api+json;version=2

C application/json;version=2

D application/vnd.example.api.v1+json

💡 Hint

Look for the version number embedded directly in the media type string.

In media type versioning, the version is part of the media type string, like 'v2' in 'application/vnd.example.api.v2+json'.

🧠 Conceptual

intermediate

Why use media type versioning in REST APIs?

Which of the following is the main reason to use media type versioning in REST APIs?

A To force clients to always use the latest API version automatically

B To embed the version number in the URL path for easy routing

C To allow clients to specify the API version via the Accept or Content-Type header

D To avoid using HTTP headers and rely only on query parameters

💡 Hint

Think about how clients tell the server which version they want.

Media type versioning lets clients specify the API version in HTTP headers like Accept or Content-Type, keeping URLs clean and supporting multiple versions.

❓ Predict Output

advanced

What is the server response Content-Type for a request with Accept: application/vnd.example.api.v3+json?

If a client sends the header:
Accept: application/vnd.example.api.v3+json
What should the server respond with in the Content-Type header?

A application/vnd.example.api+json

B application/json

C application/vnd.example.api.v2+json

D application/vnd.example.api.v3+json

💡 Hint

The server should match the version requested by the client.

The server responds with the same media type version requested by the client in the Accept header.

❓ Predict Output

advanced

What error occurs if the client requests an unsupported media type version?

If a client sends:
Accept: application/vnd.example.api.v99+json
and the server only supports versions 1 to 3, what HTTP status code should the server return?

A 406 Not Acceptable

B 200 OK

C 415 Unsupported Media Type

D 404 Not Found

💡 Hint

Think about how servers respond when they cannot provide the requested media type.

406 Not Acceptable means the server cannot produce a response matching the Accept header.

🧠 Conceptual

expert

What is a key advantage of media type versioning over URL versioning?

Which of the following best describes a key advantage of media type versioning compared to versioning via URL paths?

A It forces clients to update URLs when switching versions

B It allows multiple API versions to coexist on the same URL with content negotiation

C It simplifies server routing by using different URLs for each version

D It removes the need for HTTP headers entirely

💡 Hint

Consider how clients and servers handle multiple versions simultaneously.

Media type versioning uses content negotiation so different versions can be served from the same URL, unlike URL versioning which requires different URLs.

Practice

1. What is the main purpose of using media type versioning in REST APIs?

easy

A. To allow clients to specify API versions via custom content types

B. To encrypt API data for security

C. To speed up API response times

D. To change the API URL structure frequently

Solution

1. Step 1: Understand media type versioning concept

   Media type versioning lets clients request specific API versions by setting custom content types in headers.

2. Step 2: Identify the main purpose

   This approach helps keep APIs backward compatible by allowing multiple versions to coexist.

3. Final Answer:

   To allow clients to specify API versions via custom content types -> Option A

4. Quick Check:

   Media type versioning = clients specify versions [OK]

Hint: Remember: version info goes in content type headers [OK]

Common Mistakes:

• Confusing versioning with encryption
• Thinking URL changes are required
• Assuming it improves speed directly

2. Which HTTP header is commonly used by clients to specify the API version in media type versioning?

easy

A. Content-Type

B. Accept

C. Authorization

D. User-Agent

Solution

1. Step 1: Identify header for version negotiation

   The client uses the Accept header to tell the server which media type and version it wants.

2. Step 2: Differentiate from other headers

   Content-Type is for request body format, Authorization is for credentials, and User-Agent identifies the client software.

3. Final Answer:

   Accept -> Option B

4. Quick Check:

   Version in Accept header [OK]

Hint: Accept header tells server what version client wants [OK]

Common Mistakes:

• Using Content-Type instead of Accept for versioning
• Confusing Authorization with version info
• Thinking User-Agent controls version

3. Given this HTTP Accept header:
Accept: application/vnd.example.v2+json
What version of the API is the client requesting?

medium

A. Version 3

B. Version 1

C. Version 2

D. No version specified

Solution

1. Step 1: Parse the media type string

   The media type is application/vnd.example.v2+json. The .v2 part indicates version 2.

2. Step 2: Confirm version number meaning

   The v2 suffix is a common pattern to specify API version 2 in media type versioning.

3. Final Answer:

   Version 2 -> Option C

4. Quick Check:

   v2 in media type means version 2 [OK]

Hint: Look for .vX in media type for version number [OK]

Common Mistakes:

• Ignoring the .v2 and picking version 1
• Confusing +json suffix as version
• Assuming no version if not in URL

4. A client sends this header:
Accept: application/vnd.example.v1+json
But the server responds with version 2 data. What is the likely cause?

medium

A. Accept header syntax is invalid

B. Client sent wrong Content-Type header

C. Server does not support version 2

D. Server ignores Accept header and defaults to latest version

Solution

1. Step 1: Analyze client request and server response

   The client requests version 1 via Accept header, but server returns version 2 data.

2. Step 2: Identify server behavior

   This usually means the server ignores the Accept header and serves the latest version by default.

3. Final Answer:

   Server ignores Accept header and defaults to latest version -> Option D

4. Quick Check:

   Server ignoring Accept header causes version mismatch [OK]

Hint: Mismatch means server likely ignores Accept header [OK]

Common Mistakes:

• Blaming client Content-Type instead of Accept
• Assuming Accept header syntax error without checking
• Thinking server lacks version 2 support

5. You want to support two API versions simultaneously using media type versioning. Which server behavior best supports this?

hard

A. Parse the Accept header and return data matching the requested version

B. Ignore Accept header and always return version 2 data

C. Use URL path versioning instead of media type versioning

D. Return an error if Accept header version is not latest

Solution

1. Step 1: Understand requirement for simultaneous version support

   To support multiple versions, the server must detect which version the client wants.

2. Step 2: Identify correct server behavior

   Parsing the Accept header and returning matching version data allows backward compatibility and coexistence.

3. Final Answer:

   Parse the Accept header and return data matching the requested version -> Option A

4. Quick Check:

   Server parses Accept header to serve requested version [OK]

Hint: Server must read Accept header to serve correct version [OK]

Common Mistakes:

• Ignoring Accept header and forcing one version
• Switching to URL versioning instead of media type
• Returning errors instead of supporting old versions