/**
 * The runtime hook handler: Claude Code pipes a PostToolUse event JSON to this on
 * stdin; we inspect the untrusted tool result and, when it carries a prompt
 * injection, REWRITE the result Claude is about to read (the documented
 * `updatedToolOutput` mechanism) so the agent never acts on the poisoned content.
 *
 * It fails OPEN: any parse/inspect error → pass through silently. A guard that
 * bricks the agent on its own bug is worse than one that occasionally misses.
 */
import type { GuardResult } from "./types.js";
export declare function buildResponse(content: string): {
    output: unknown | null;
    result: GuardResult;
};
/** PreToolUse: screen a command the agent is about to run. */
export declare function buildCommandResponse(command: string): unknown | null;
/** PreToolUse: screen a file write (path + content) the agent is about to make. */
export declare function buildFileWriteResponse(path: string, content: string): unknown | null;
/** CLI entry for `nexus guard check`. Routes by hook event:
 *  PreToolUse → command screening (can block); PostToolUse → content redaction. */
export declare function runHandler(): Promise<void>;