Problem Details (RFC 7807) format in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Problem Details (RFC 7807) format in REST APIs?

It provides a standardized way to return machine-readable error details in HTTP responses, making it easier for clients to understand and handle errors.

beginner

Name the five standard fields defined in the Problem Details (RFC 7807) format.

The five standard fields are: type, title, status, detail, and instance.

beginner

What does the type field represent in the Problem Details format?

It is a URI reference that identifies the problem type. It helps clients understand the kind of error without reading the full message.

beginner

How should the status field be used in the Problem Details response?

It should contain the HTTP status code generated by the server for this error, such as 404 or 500.

intermediate

Can you add custom fields to the Problem Details (RFC 7807) JSON response? If yes, how?

Yes, you can add custom fields alongside the standard ones to provide extra information specific to your API or error scenario.

Which field in RFC 7807 contains a short, human-readable summary of the problem?

A type

B instance

C detail

D title

The title field provides a short, human-readable summary of the problem.

What HTTP status code should be included in the status field?

A The HTTP status code of the error response

B Any random number

C Always 200

D The client IP address

The status field must contain the HTTP status code that the server returned for the error.

Is the instance field optional or required in the Problem Details format?

A Required

B Deprecated

C Optional

D Must be empty

The instance field is optional and can provide a URI reference that identifies the specific occurrence of the problem.

What content type should be used when sending a Problem Details response?

A application/problem+json

B text/html

C application/json

D text/plain

The official media type for Problem Details JSON responses is application/problem+json.

Can the type field be a blank string?

A Yes, it can be blank

B No, it must be a valid URI or omitted

C It must be a number

D It must be the HTTP status code

The type field should be a URI identifying the problem type or omitted if unknown; it should not be blank.

Explain the purpose and main fields of the Problem Details (RFC 7807) format.

Think about how APIs tell clients what went wrong in a clear way.

Describe how you would implement a Problem Details response for a 404 Not Found error.

Imagine your API tells a client that a resource is missing.

Practice

1. What is the main purpose of the Problem Details (RFC 7807) format in REST APIs?

easy

A. To speed up API response times

B. To standardize error responses so clients can understand errors better

C. To encrypt API responses for security

D. To format successful data responses uniformly

Solution

1. Step 1: Understand the role of Problem Details format

   The format is designed to provide a consistent way to report errors in APIs.

2. Step 2: Identify the main benefit

   It helps clients understand and handle errors better by standardizing error responses.

3. Final Answer:

   To standardize error responses so clients can understand errors better -> Option B

4. Quick Check:

   Purpose = Standardize error responses [OK]

Hint: Remember: Problem Details = standardized error info [OK]

Common Mistakes:

• Confusing error format with data encryption
• Thinking it speeds up API responses
• Assuming it formats successful responses

2. Which of the following is a REQUIRED field in the Problem Details JSON object according to RFC 7807?

easy

A. type

B. status

C. detail

D. instance

Solution

1. Step 1: Recall required fields in RFC 7807

   The RFC requires the "type" field to identify the error type URI.

2. Step 2: Check other fields

   Fields like "status", "detail", and "instance" are optional but recommended.

3. Final Answer:

   type -> Option A

4. Quick Check:

   Required field = type [OK]

Hint: Only 'type' is mandatory in Problem Details [OK]

Common Mistakes:

• Assuming 'status' is required
• Confusing 'detail' as mandatory
• Thinking 'instance' is always needed

3. Given this Problem Details JSON response:

{"type": "https://example.com/probs/out-of-credit", "title": "You do not have enough credit.", "status": 403, "detail": "Your current balance is 30, but that costs 50.", "instance": "/account/12345/msgs/abc"}

What is the HTTP status code indicated?

medium

A. 403

B. 404

C. 200

D. 500

Solution

1. Step 1: Locate the status field in JSON

   The JSON has "status": 403, which indicates the HTTP status code.

2. Step 2: Understand the meaning of 403

   403 means Forbidden, matching the error about insufficient credit.

3. Final Answer:

   403 -> Option A

4. Quick Check:

   Status code = 403 [OK]

Hint: Look for 'status' field for HTTP code [OK]

Common Mistakes:

• Confusing status with 'detail' content
• Picking 200 as success code
• Ignoring the numeric status field

4. You receive this Problem Details JSON:

{"title": "Invalid input", "status": 400, "detail": "Missing required field 'name'"}

What is missing that violates RFC 7807 requirements?

medium

A. The 'title' field should be a URL

B. The 'status' field should be a string

C. The 'detail' field should be omitted

D. The 'type' field is missing

Solution

1. Step 1: Check required fields in the JSON

   The 'type' field is required by RFC 7807 but is missing here.

2. Step 2: Validate other fields

   'status' is correctly a number, 'detail' and 'title' are valid types.

3. Final Answer:

   The 'type' field is missing -> Option D

4. Quick Check:

   Missing required field = type [OK]

Hint: Always include 'type' field in Problem Details [OK]

Common Mistakes:

• Thinking 'status' must be string
• Removing 'detail' field
• Assuming 'title' must be URL

5. You want to create a Problem Details response for a rate limit error. Which JSON object correctly follows RFC 7807 and clearly informs the client about the error?

hard

A. {"type": "rate-limit", "title": "Error", "status": 429, "detail": "Limit reached"}

B. {"title": "Rate limit exceeded", "status": "429", "detail": "Too many requests", "instance": "/api/v1/resource"}

C. {"type": "https://example.com/probs/rate-limit", "title": "Rate limit exceeded", "status": 429, "detail": "You have sent too many requests in a short time.", "instance": "/api/v1/resource"}

D. {"type": "https://example.com/probs/rate-limit", "title": "Rate limit exceeded", "status": 200, "detail": "Too many requests"}

Solution

1. Step 1: Check required fields and correct types

   {"type": "https://example.com/probs/rate-limit", "title": "Rate limit exceeded", "status": 429, "detail": "You have sent too many requests in a short time.", "instance": "/api/v1/resource"} includes 'type' as a URI, 'title', numeric 'status' 429, 'detail', and 'instance' fields correctly.

2. Step 2: Validate status code and clarity

   Status 429 means Too Many Requests, matching the error. Other options have missing or wrong fields or wrong status codes.

3. Final Answer:

   {"type": "https://example.com/probs/rate-limit", "title": "Rate limit exceeded", "status": 429, "detail": "You have sent too many requests in a short time.", "instance": "/api/v1/resource"} -> Option C

4. Quick Check:

   Correct fields and status = {"type": "https://example.com/probs/rate-limit", "title": "Rate limit exceeded", "status": 429, "detail": "You have sent too many requests in a short time.", "instance": "/api/v1/resource"} [OK]

Hint: Use URI in 'type' and correct numeric 'status' [OK]

Common Mistakes:

• Using string instead of number for status
• Missing 'type' or using non-URI string
• Wrong HTTP status code for error