/**
 * Prompt-injection scanner for persistent memory block writes.
 *
 * Persistent blocks get injected into the system prompt verbatim every
 * session. An attacker who can persuade the agent to call
 * `memory_block({action:'add', content: 'ignore previous instructions...'})`
 * effectively rewrites the system prompt for all future sessions of
 * that user. The scanner blocks the most common shapes.
 *
 * Pattern source: aligned with hermes-agent `tools/memory_tool.py`
 * `_MEMORY_THREAT_PATTERNS`, simplified to the highest-signal subset.
 * The `(?:\\w+\\s+)*` between key tokens prevents trivial bypass via
 * filler words ("ignore all PRIOR instructions" matches "ignore prior
 * instructions" matches "ignore the previous given instructions").
 *
 * Failure mode: false positives cost the user a write attempt — the
 * tool returns a structured error and the agent can retry with
 * different wording. False negatives let through a real injection, so
 * we err on the side of catching more.
 */
export interface SafetyScanResult {
    safe: boolean;
    /** When unsafe: the id of the matched pattern. */
    matchedPattern?: string;
    /** When unsafe: the substring of the input that triggered the match. */
    matchedText?: string;
}
/**
 * Scan a candidate write for prompt-injection patterns. Returns
 * `{ safe: true }` if no patterns matched, or `{ safe: false, matchedPattern, matchedText }`.
 */
export declare function scanMemoryWrite(content: string): SafetyScanResult;