This is just a guide to help you decide. Ask yourself these questions:

To Read Entities

1. Can your client code (JavaScript) work with the standard JSON format?
   1. AND do you only need standard REST commands like GetAll and GetOneById  ➡ Entity REST APIs
   2. AND do you need special predefined queries like Sort By XXX or Get Top 20 From Category ABC  ➡ Query REST APIs
2. If you can't use the standard JSON format but need something custom ➡ Custom WebAPIs
3. If you need very special queries ➡ Custom WebAPIs

To Create/Update Entities

In most cases you should use ➡ Entity REST APIs

Special cases like the following will need ➡ Custom WebAPIs

• Custom logic before saving the data like:
  • Custom validation
  • Generate additional values on the server like special titles or time stamps
  • Look-Up additional values like User-IDs, data from SQL etc.
• Also save files / attachments / images? 
• Also send e-mails? 
• Also change other data like SQL 
• Perform custom security checks beyond the features of 2sxc/EAV
• Make an item a Metadata for something else
• Use other keys than the normal id/guid keys

To Delete Entities

In most cases you can use the ➡ Entity REST APIs

Special cases like the following will need ➡ Custom WebAPIs

• Special security checks
• Special validation checks