Endpoint documentation structure in Rest API - Mini Project: Build & Apply

Endpoint documentation structure

📖 Scenario: You are building a simple REST API for a bookstore. You want to create clear documentation for one of your API endpoints so that other developers can understand how to use it.

🎯 Goal: Create a structured documentation for a REST API endpoint that shows the HTTP method, URL path, description, request parameters, and example response.

📋 What You'll Learn

Create a dictionary called endpoint_doc with keys: method, path, description, parameters, and response_example

Set method to the HTTP method as a string

Set path to the URL path as a string

Set description to a short explanation string

Set parameters to a list of dictionaries, each with name, type, and required keys

Set response_example to a dictionary showing a sample JSON response

Print the endpoint_doc dictionary at the end

💡 Why This Matters

🌍 Real World

Clear API documentation helps developers understand how to use your web services correctly and quickly.

💼 Career

API documentation skills are essential for backend developers, API designers, and technical writers working with web services.

1

Create the basic endpoint documentation dictionary

Create a dictionary called endpoint_doc with keys method, path, and description. Set method to "GET", path to "/books", and description to "Retrieve a list of books".

Rest API

# Create the endpoint_doc dictionary with method, path, and description
# Your code here

Hint

Use curly braces {} to create a dictionary and assign the keys and values exactly as instructed.

2

Add request parameters list

Add a key parameters to the endpoint_doc dictionary. Set it to a list with two dictionaries: first with name as "author", type as "string", and required as False; second with name as "year", type as "integer", and required as False.

Rest API

endpoint_doc = {
    "method": "GET",
    "path": "/books",
    "description": "Retrieve a list of books"
}
# Add the parameters key with the list of parameter dictionaries
# Your code here

Hint

Remember that parameters is a list of dictionaries. Use square brackets [] for the list and curly braces {} for each dictionary.

3

Add example response dictionary

Add a key response_example to the endpoint_doc dictionary. Set it to a dictionary with a key books whose value is a list of two dictionaries. The first dictionary has id: 1, title: "The Great Gatsby", author: "F. Scott Fitzgerald". The second dictionary has id: 2, title: "1984", author: "George Orwell".

Rest API

endpoint_doc = {
    "method": "GET",
    "path": "/books",
    "description": "Retrieve a list of books",
    "parameters": [
        {"name": "author", "type": "string", "required": False},
        {"name": "year", "type": "integer", "required": False}
    ]
}
# Add the response_example key with the example response dictionary
# Your code here

Hint

Use nested dictionaries and lists to represent the example JSON response structure.

4

Print the endpoint documentation

Write a print statement to display the endpoint_doc dictionary.

Rest API

endpoint_doc = {
    "method": "GET",
    "path": "/books",
    "description": "Retrieve a list of books",
    "parameters": [
        {"name": "author", "type": "string", "required": False},
        {"name": "year", "type": "integer", "required": False}
    ],
    "response_example": {
        "books": [
            {"id": 1, "title": "The Great Gatsby", "author": "F. Scott Fitzgerald"},
            {"id": 2, "title": "1984", "author": "George Orwell"}
        ]
    }
}
# Print the endpoint_doc dictionary
# Your code here

Hint

Use print(endpoint_doc) to display the dictionary.

Practice

1. What is the main purpose of endpoint documentation in a REST API?

easy

A. To explain how to use each API URL including methods and parameters

B. To store user data securely

C. To improve the speed of the API server

D. To design the user interface of a website

Solution

1. Step 1: Understand the role of endpoint documentation

   Endpoint documentation describes how to use each API URL, including methods and parameters.

2. Step 2: Compare options with this role

   Only To explain how to use each API URL including methods and parameters matches this purpose; others describe unrelated tasks.

3. Final Answer:

   To explain how to use each API URL including methods and parameters -> Option A

4. Quick Check:

   Endpoint documentation = Usage guide [OK]

Hint: Think: What helps users understand API URLs? [OK]

Common Mistakes:

• Confusing documentation with data storage
• Mixing API documentation with UI design
• Assuming documentation improves server speed

2. Which of the following is the correct way to document the HTTP method in an endpoint documentation?

easy

A. "method": "GET"

B. "method" = GET

C. method: GET;

D. GET

Solution

1. Step 1: Identify proper JSON syntax for documentation

   Endpoint docs often use JSON or similar formats; key-value pairs use colon and quotes for strings.

2. Step 2: Check each option's syntax

   "method": "GET" uses correct JSON syntax with quotes and colon; others use invalid or non-standard syntax.

3. Final Answer:

   "method": "GET" -> Option A

4. Quick Check:

   JSON key-value = colon + quotes [OK]

Hint: Remember JSON syntax: key in quotes, colon, value in quotes [OK]

Common Mistakes:

• Using equal sign instead of colon
• Omitting quotes around strings
• Using XML tags instead of JSON

3. Given this endpoint documentation snippet:

{
  "endpoint": "/users/{id}",
  "method": "GET",
  "parameters": {
    "id": "integer"
  },
  "response": {
    "200": "User object",
    "404": "Not Found"
  }
}

What is the expected response if the user ID does not exist?

medium

A. User object with empty fields

B. 404 Not Found error

C. 200 OK with error message

D. 500 Internal Server Error

Solution

1. Step 1: Read the response codes in the documentation

   The response section shows "404": "Not Found" which means if the user ID is missing, a 404 error is returned.

2. Step 2: Match the scenario to the response code

   Since the user ID does not exist, the API returns 404 Not Found, not 200 or 500.

3. Final Answer:

   404 Not Found error -> Option B

4. Quick Check:

   Missing resource = 404 Not Found [OK]

Hint: 404 means resource not found, check response codes [OK]

Common Mistakes:

• Assuming 200 OK always returns
• Confusing 404 with 500 server error
• Expecting empty user object instead of error

4. You see this endpoint documentation snippet:

{
  "endpoint": "/items",
  "method": "POST",
  "parameters": {
    "name": "string",
    "quantity": "integer"
  },
  "response": {
    "201": "Item created"
  }
}

But the API returns a 400 error when you send the request. What is the most likely mistake in the documentation?

medium

A. The endpoint URL is missing a trailing slash

B. The HTTP method should be GET, not POST

C. Parameters should be inside a "requestBody" section, not "parameters"

D. The response code 201 is incorrect for creation

Solution

1. Step 1: Understand POST request structure

   POST requests usually send data in the request body, not as URL parameters.

2. Step 2: Check documentation structure

   Parameters listed under "parameters" implies URL/query parameters; for POST data, it should be under "requestBody".

3. Final Answer:

   Parameters should be inside a "requestBody" section, not "parameters" -> Option C

4. Quick Check:

   POST data = requestBody, not parameters [OK]

Hint: POST data goes in requestBody, not parameters [OK]

Common Mistakes:

• Confusing query parameters with request body
• Changing HTTP method incorrectly
• Ignoring correct response codes

5. You want to document an endpoint that updates a user's email. It uses PATCH method at /users/{id}. The request body must include email as a string. The response returns 200 with updated user data or 400 if email is invalid. Which is the best way to structure this documentation snippet?

hard

A. {
"endpoint": "/users/{id}",
"method": "PATCH",
"parameters": {
"id": "integer",
"email": "string"
},
"response": {
"200": "Updated user object",
"400": "Invalid email error"
}
}

B. {
"endpoint": "/users",
"method": "PATCH",
"parameters": {
"email": "string"
},
"response": {
"200": "Updated user object",
"400": "Invalid email error"
}
}

C. {
"endpoint": "/users/{id}",
"method": "POST",
"parameters": {
"id": "integer",
"email": "string"
},
"response": {
"200": "Updated user object",
"400": "Invalid email error"
}
}

D. {
"endpoint": "/users/{id}",
"method": "PATCH",
"parameters": {
"id": "integer"
},
"requestBody": {
"email": "string"
},
"response": {
"200": "Updated user object",
"400": "Invalid email error"
}
}

Solution

1. Step 1: Identify correct HTTP method and endpoint

   The method is PATCH and endpoint includes user ID as a path parameter "/users/{id}".

2. Step 2: Separate path parameters and request body

   "id" is a path parameter, so it goes under "parameters"; "email" is sent in request body, so it belongs in "requestBody".

3. Step 3: Check response codes and descriptions

   Response codes 200 and 400 with correct descriptions match the scenario.

4. Final Answer:

   { "endpoint": "/users/{id}", "method": "PATCH", "parameters": { "id": "integer" }, "requestBody": { "email": "string" }, "response": { "200": "Updated user object", "400": "Invalid email error" } } -> Option D

5. Quick Check:

   Path params + requestBody + responses = { "endpoint": "/users/{id}", "method": "PATCH", "parameters": { "id": "integer" }, "requestBody": { "email": "string" }, "response": { "200": "Updated user object", "400": "Invalid email error" } } [OK]

Hint: Put path params in parameters, data in requestBody [OK]

Common Mistakes:

• Putting request body fields in parameters
• Using wrong HTTP method
• Omitting requestBody section