/**
 * Thrown when a persisted artifact's `schema_version` is present but not the
 * supported one. A DISTINCT type (not each loader's generic parse error) so a
 * caller can tell "incompatible version" from "corrupt/malformed" and choose to
 * recover: a rebuildable cache (profile/queries) treats it as absent and
 * rebuilds, while a historical snapshot or an explicit file lets it surface.
 */
export declare class SchemaVersionError extends Error {
    readonly found: unknown;
    constructor(found: unknown);
}
/** A record of parsed-but-unvalidated fields. */
export type Unvalidated = Record<string, unknown>;
/** Field-level assertions bound to a caller-supplied failure sink. */
export interface StructValidator {
    /** Assert `value` is a non-null, non-array object; return it as a record. */
    object(value: unknown, label?: string): Unvalidated;
    /** Assert `schema_version` is present AND equals the supported version (rule #2). */
    schemaVersion(obj: Unvalidated): void;
    /** Assert `obj[key]` is a string. */
    string(obj: Unvalidated, key: string): void;
    /** Assert `obj[key]` is a number. */
    number(obj: Unvalidated, key: string): void;
    /** Assert `obj[key]` is a number or `null` (an intentionally nullable field). */
    numberOrNull(obj: Unvalidated, key: string): void;
    /** Assert `obj[key]` is an array. */
    array(obj: Unvalidated, key: string): void;
    /** Assert `obj[key]` is a non-null, non-array object. */
    objectField(obj: Unvalidated, key: string): void;
}
/**
 * Build a {@link StructValidator} that reports every failure through `fail`.
 * `fail` must not return (it throws the caller's domain-specific error), which
 * lets the assertions narrow types for the code that follows them.
 */
export declare function createValidator(fail: (why: string) => never): StructValidator;