[SOLVED] Does adding too much validations for user inputs is a good practice while creating REST APIs

Does adding too much validations for user inputs is a good practice while creating REST APIs

I'm building a REST api which take some inputs like id,customer_id,firstname,lastname,contact,email,updated_time,created_time. Before processing these inputs, i have added validations to check if

id and customer is number
firstname is not a null and string,
created and updated time are not null and empty string
email id is in valid format
contact field is number
check for email and contact already exist in database

And few more validations also made. But it made the code redundant and reduced code readability and maintainability. Is it a good practice to include these much validations in a single api call?

Tried making a common structure for api response. But I want to produce different error response in each conditions.

Solution

I don't know what programming language you're using, but most of this can be handled by a good MVC framework.

For example using Spring MVC (Java): https://www.baeldung.com/spring-boot-bean-validation

In that example, the author returns an HTTP response with status 400 for errors, and returns a JSON structure with the error message per field in the body.