Keep useful literals without making false assertions

First, build a mental model

Inference chooses a type broad enough for the intended use. `as const` preserves literals and readonly properties; `satisfies` checks compatibility while retaining the expression's useful inferred detail.

1. A mutable string property often widens to string.
2. as const keeps literal information; it does not freeze runtime objects.
3. satisfies checks a contract without replacing the expression with the broad target type.
4. Template literal types construct finite vocabularies from unions.

type EventName = `${'player' | 'order'}:${'created' | 'updated'}`;
const route = { method: 'GET', path: '/orders' } as const;
const limits = { small: 10, large: 50 } satisfies Record<string, number>;
type LimitName = keyof typeof limits;
const event: EventName = 'player:updated';
const selected: LimitName = 'small';

1. Literal

   route.method is the literal GET, not every string.

2. Shape check

   limits must contain numeric values; its known keys remain small | large.

3. Vocabulary

   EventName permits four combinations.