/**
 * Lightweight read-only Cypher guard.
 *
 * Mirrors {@link ./sql-guard.ts} but for the Cypher dialect the graph-db
 * backend accepts. The guard's job is to reject obvious write verbs before
 * they reach the native binding — the native engine does enforce its own
 * read-only mode when the connection is opened read-only, but we want a
 * typed rejection earlier in the stack plus a consistent user-facing
 * message regardless of backend.
 *
 * Scope:
 *   - Allowlist of reader clauses: MATCH, RETURN, WITH, WHERE, ORDER BY,
 *     LIMIT, SKIP, UNWIND.
 *   - `CALL` is rejected unless the invocation is exactly one of the two
 *     known read-only index procedures the FTS / vector surfaces need:
 *     `QUERY_FTS_INDEX(...)` or `QUERY_VECTOR_INDEX(...)`.
 *   - Writes are rejected: CREATE, DELETE, SET, MERGE, REMOVE, DROP (plus
 *     the DDL / DML verbs the native binding documents even if they are
 *     not technically Cypher — ALTER, COPY, IMPORT, EXPORT, CHECKPOINT,
 *     INSTALL, LOAD EXTENSION).
 *
 * Tokenization is lexical (regex over the un-commented query text) — this
 * is a defense-in-depth check, not a full Cypher parser. Strings in which
 * a banned keyword legitimately appears (e.g. a node property literal
 * containing the word "DELETE") are correctly ignored because the string-
 * stripping pass drops them before the keyword sweep.
 *
 * Known limitation: the string-stripper walks the raw source character by
 * character and does not understand Cypher's full quoting grammar (no
 * backtick-delimited identifier handling, no multi-line triple-quotes).
 * That is acceptable for v1 — the allowlist-first leading-keyword check
 * provides the load-bearing guarantee and the string stripper is only
 * responsible for the "banned keyword inside a string literal" edge case
 * on the single/double-quoted forms we actually use in practice.
 */
export declare class CypherGuardError extends Error {
    constructor(message: string);
}
/**
 * Reject any Cypher that is not a single read-only statement. Call before
 * handing the text to the graph-db backend.
 *
 * Contract:
 *   - Input must be a non-empty string.
 *   - Statement must start with one of ALLOWED_LEADING_KEYWORDS, or be a
 *     CALL to one of ALLOWED_CALL_PROCEDURES.
 *   - No banned write verb may appear anywhere in the statement body (after
 *     comments + string literals are stripped).
 *
 * Throws {@link CypherGuardError} on any violation.
 */
export declare function assertReadOnlyCypher(cypher: string): void;
//# sourceMappingURL=cypher-guard.d.ts.map