`FlagConfig`

Compile-time state carried through the builder chain.

Adding new tracked properties only requires extending this interface — no builder signature changes.

Signatures

interface FlagConfig {}

The runtime kind discriminator, mirroring FlagKind.

flagKind: "string" | "number" | "boolean" | "enum" | "array" | "custom";

What an unresolved optional flag becomes at the action boundary.

optionalFallback: OptionalFallback;

Whether the flag is optional, required, or has a default.

presence: "optional" | "required" | "defaulted";

The resolved value type (e.g. string, number, 'us' | 'eu').

valueType: unknown;