What information should be publicly available, and what needs to be kept secret?

Information that does not pose a security threat and is necessary for interaction with users or other systems should be publicly available. For example:

• API documentation
• Public interfaces and methods
• Public data and results

Secrets should be kept:

• Passwords, access keys, tokens
• Personal user data (PII)
• Internal algorithms and business logic, if it is a trade secret
• Security configurations and settings

In Python, to hide data, naming conventions are used (for example, prefix _ for private attributes), and secrets are stored outside the code (for example, in environment variables).