Enums & Const

Enum (union of literals)


const statusSchema = new SchemaBuilder()
  .enum(["pending", "approved", "rejected", "cancelled"])
  .build();
type Status = Jet.Infer<typeof statusSchema>;
// "pending" | "approved" | "rejected" | "cancelled"
 
const prioritySchema = new SchemaBuilder().enum([1, 2, 3, 4, 5]).build();
type Priority = Jet.Infer<typeof prioritySchema>;
// 1 | 2 | 3 | 4 | 5
 
const mixedSchema = new SchemaBuilder().enum(["active", 1, true, null]).build();
type Mixed = Jet.Infer<typeof mixedSchema>;
// "active" | 1 | true | null

Const (single literal value)


const apiVersionSchema = new SchemaBuilder().const("v2").build();
type ApiVersion = Jet.Infer<typeof apiVersionSchema>;
// "v2" (not string)
 
const maxRetriesSchema = new SchemaBuilder().const(3).build();
type MaxRetries = Jet.Infer<typeof maxRetriesSchema>;
// 3 (not number)
 
const productionSchema = new SchemaBuilder().const(true).build();
type Production = Jet.Infer<typeof productionSchema>;
// true (not boolean)

No as const needed. Literal types are inferred automatically from .enum() and .const() values.

If const or enum is given a $data reference, the type is always any — the runtime value is unknown at compile time.