CQS Handler Signatures for Business Logic Entry Points

Goal

Apply a consistent signature pattern to business-logic entry points when Command-Query Separation is already the governing design rule.

This skill refines the shape of command handlers and query handlers. It does not replace the underlying CQS rule. Keep using the CQS distinction between commands and queries, then apply this signature convention on top of it.

Core Naming Rule

Name the entry point with:

• an infinitive verb
• the suffix command handler for commands
• the suffix query handler for queries

Translate that pattern into the syntax and style of the language in use.

Examples: