State and Injection¶

Sayer supports dependency-style injection for:

• click.Context
• subclasses of State
• custom injection flows via custom group wrappers

Injection Rules¶

• click.Context parameters receive the active Click context.
• State subclasses are instantiated and cached in command context.
• Other parameters are bound from parsed CLI inputs.

When to Use State¶

• shared configuration loaded once
• runtime flags reused across commands
• shared client objects in one CLI session

Common Pitfalls¶

• using mutable global module variables instead of injected state
• hiding required setup in callbacks instead of explicit state objects
• mixing unrelated dependencies in one state class

Related¶

• Feature Guide: Context Injection
• Feature Guide: State
• Command Lifecycle