/**
 * Skill Behavioral Fingerprint
 *
 * Tracks what each skill "normally does" across invocations, then detects
 * behavioral drift when a previously-trusted skill starts acting differently.
 *
 * Solves the "installed then turns malicious" scenario:
 * - First N invocations: build fingerprint (what APIs, what patterns, what scope)
 * - After fingerprint stabilizes: flag any deviation as anomaly
 *
 * @module agent-threat-rules/skill-fingerprint
 */
import type { AgentEvent } from './types.js';
/** Behavioral capabilities observed for a skill */
interface SkillCapabilities {
    /** Seen filesystem operations (read/write/delete) */
    readonly filesystemOps: ReadonlySet<string>;
    /** Seen network destinations (hostnames) */
    readonly networkTargets: ReadonlySet<string>;
    /** Seen environment variable accesses */
    readonly envAccesses: ReadonlySet<string>;
    /** Seen child process executions */
    readonly processExecs: ReadonlySet<string>;
    /** Seen output patterns (categories: data, error, redirect, exfiltration) */
    readonly outputPatterns: ReadonlySet<string>;
}
/** Immutable fingerprint snapshot */
export interface SkillFingerprint {
    readonly skillName: string;
    readonly invocationCount: number;
    readonly firstSeen: number;
    readonly lastSeen: number;
    readonly isStable: boolean;
    readonly capabilities: SkillCapabilities;
    /** Hash of capabilities for quick comparison */
    readonly capabilityHash: string;
}
/** Anomaly when behavior deviates from fingerprint */
export interface BehaviorAnomaly {
    readonly skillName: string;
    readonly anomalyType: 'new_filesystem_op' | 'new_network_target' | 'new_env_access' | 'new_process_exec' | 'new_output_pattern' | 'capability_expansion';
    readonly description: string;
    readonly severity: 'low' | 'medium' | 'high' | 'critical';
    readonly newValue: string;
    readonly timestamp: number;
}
export interface SkillFingerprintConfig {
    /** Minimum invocations before fingerprint can stabilize (default: 10) */
    stabilityThreshold?: number;
    /** Consecutive clean invocations to mark stable (default: 5) */
    stableStreak?: number;
}
export declare class SkillFingerprintStore {
    private readonly fingerprints;
    private readonly stabilityThreshold;
    private readonly stableStreak;
    constructor(config?: SkillFingerprintConfig);
    /**
     * Record a skill invocation and detect behavioral anomalies.
     * Returns anomalies if the fingerprint was stable and new capabilities appeared.
     */
    recordInvocation(skillName: string, event: AgentEvent): readonly BehaviorAnomaly[];
    /**
     * Get an immutable fingerprint snapshot for a skill.
     */
    getFingerprint(skillName: string): SkillFingerprint | undefined;
    /** Get all tracked skill names */
    getTrackedSkills(): string[];
    /** Get count of stable fingerprints */
    getStableCount(): number;
    /** Get total tracked skills */
    getTrackedCount(): number;
    /**
     * Reset a skill's fingerprint (e.g., after a legitimate update).
     */
    resetFingerprint(skillName: string): void;
    /**
     * Evict fingerprints not seen since cutoffMs ago.
     */
    cleanup(cutoffMs: number): number;
    private getOrCreate;
    private computeCapabilityHash;
}
export {};
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