Flags vs settings¶

RTB scaffolds two different ways for a tool to take input, and the scaffolder has a distinct verb for each. They are not interchangeable — picking the right one is about where the value comes from and how long it lives.

flag — a clap argument the user types on the command line for one invocation (transient). setting — a typed field on AppConfig the tool reads from its layered config: config file, environment, or a CLI override (persistent).

At a glance¶

	`flag`	`setting`
Scaffolder verb	`rtb generate flag` / `rtb remove flag`	`rtb generate setting` / `rtb remove setting`
Lives in	`src/commands/<cmd>.rs` (a clap `Arg`)	`src/main.rs` (`AppConfig` field)
Scope	one command	whole tool
Source	typed on the CLI per run	config file → env (`MYTOOL_<NAME>`) → CLI override
Lifetime	transient (this invocation)	persistent (configured once)
Marker region	`// rtb:flags-begin/-end`	`// rtb:settings-begin/-end`

When to use which¶

Reach for a flag when the value is an action parameter the user decides at call time: deploy --region eu, build --release, --dry-run.
Reach for a setting when the value is configuration the user sets once and the tool reuses: an API endpoint, a default output directory, a retry count. These come from the figment layers (defaults → file → env → CLI) — see Configuration.

A value can legitimately be both: expose a setting for the configured default and a flag that overrides it for one run. RTB keeps them as two explicit pieces rather than fusing them.

Why two concepts (the gtb contrast)¶

Go Tool Base (cobra + viper) fuses these into a single persistent flag — a CLI flag bound to a dynamic config bag. RTB deliberately diverges: figment config is a typed AppConfig struct, not a GetString("key") bag (see why-rtb). So a clap flag and a config field are genuinely different things in RTB, and the scaffolder names them separately. remove flag is the gtb-parity verb; setting is RTB-native.

The setting verb was named config-field before cli-bin v0.6.0. The rename (and its inverse remove setting) is covered by 2026-06-22-scaffolder-setting-verb.