Problem Details (RFC 7807) format in Rest API - Mini Project: Build & Apply

Problem Details (RFC 7807) format

📖 Scenario: You are building a REST API that needs to return error information in a clear and standard way.Using the Problem Details format (RFC 7807) helps clients understand what went wrong.

🎯 Goal: Create a JSON object that follows the Problem Details (RFC 7807) format to describe an error response.

📋 What You'll Learn

Create a dictionary called problem_details with keys type, title, status, detail, and instance

Set type to "https://example.com/probs/out-of-credit"

Set title to "You do not have enough credit."

Set status to 403

Set detail to "Your current balance is 30, but that costs 50."

Set instance to "/account/12345/msgs/abc"

Print the problem_details dictionary as a JSON string

💡 Why This Matters

🌍 Real World

APIs use the Problem Details format to send clear error messages to clients, making it easier to handle errors.

💼 Career

Understanding standard error formats is important for backend developers and API designers to build reliable and user-friendly services.

1

Create the Problem Details dictionary

Create a dictionary called problem_details with these exact keys and values: "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.", and "instance": "/account/12345/msgs/abc".

Rest API

# Create the problem_details dictionary with the required keys and values
# Your code here

Hint

Remember to use exact keys and values as strings or numbers as shown.

2

Import the json module

Add the line import json at the top of your code to use JSON functions.

Rest API

problem_details = {
    "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"
}

# Import the json module
# Your code here

Hint

Use the import statement exactly as shown.

3

Convert the dictionary to a JSON string

Use json.dumps() to convert the problem_details dictionary to a JSON string and store it in a variable called json_output.

Rest API

import json

problem_details = {
    "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"
}

# Convert problem_details to JSON string and store in json_output
# Your code here

Hint

Use json.dumps() exactly with problem_details as the argument.

4

Print the JSON output

Write a print() statement to display the json_output variable.

Rest API

import json

problem_details = {
    "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"
}

json_output = json.dumps(problem_details)

# Print the JSON string
# Your code here

Hint

Use print(json_output) exactly to show the JSON string.

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