Plural vs singular resource names in Rest API - Visual Side-by-Side Comparison

Concept Flow - Plural vs singular resource names

Client sends request

↓

Check resource name

↓

Plural

↓

Handle as collection

↓

Return response

The API checks if the resource name is plural or singular to decide if it handles a collection or a single item.

Execution Sample

Rest API

GET /users
GET /user/123
POST /users
DELETE /user/123

Shows requests using plural for collections and singular for single items.

Execution Table

Step	Request	Resource Name	Type	Action	Response
1	GET /users	users	Plural	Return list of users	200 OK with user list
2	GET /user/123	user	Singular	Return user with ID 123	200 OK with user data
3	POST /users	users	Plural	Create new user in collection	201 Created
4	DELETE /user/123	user	Singular	Delete user with ID 123	204 No Content
5	GET /user	user	Singular	Missing ID, error	400 Bad Request

💡 Requests stop after response is sent.

Variable Tracker

Variable	Start	After 1	After 2	After 3	After 4	After 5
Resource Name		users	user	users	user	user
Type		Plural	Singular	Plural	Singular	Singular
Action		Return list	Return single	Create new	Delete single	Error - missing ID
Response		200 OK list	200 OK single	201 Created	204 No Content	400 Bad Request

Key Moments - 3 Insights

Why do we use plural names like /users for collections?

Plural names clearly indicate the resource is a collection, so the API returns multiple items, as shown in execution_table rows 1 and 3.

What happens if we use singular without an ID, like GET /user?

The API expects an ID for singular resources. Without it, it returns an error, as seen in execution_table row 5.

Can singular resource names be used for creating new items?

No, creation is done on the collection (plural) endpoint, like POST /users in row 3.

Visual Quiz - 3 Questions

Look at the execution_table, what type is the resource name 'users' in step 1?

A Singular

B Plural

C Unknown

D Both

💡 Hint

Check the 'Type' column in execution_table row 1.

At which step does the API return a 400 Bad Request error?

A Step 2

B Step 3

C Step 5

D Step 4

💡 Hint

Look at the 'Response' column for the error status in execution_table.

If we change POST /users to POST /user, what would likely happen?

A Return an error because singular is for single items

B Return list of users

C Create a new user successfully

D Delete a user

💡 Hint

Refer to key_moments about creation using plural resource names.

Concept Snapshot

Use plural resource names (e.g., /users) for collections.
Use singular resource names (e.g., /user/123) for single items.
POST and GET on plural handle collections.
GET, DELETE on singular handle single items.
Missing ID on singular causes errors.

Full Transcript

This visual execution shows how REST APIs use plural resource names for collections and singular names for single items. The API checks the resource name in the request. If plural, it treats it as a collection and returns or modifies multiple items. If singular with an ID, it handles a single item. Missing IDs on singular resources cause errors. For example, GET /users returns a list, while GET /user/123 returns one user. POST is done on plural to create new items. This helps keep API design clear and consistent.