/**
 * S3-backed skill store.
 *
 * Layout (curator-compatible):
 *   <prefix>skills/<id>.json  — one JSON-serialized SkillDefinition per object
 *   <prefix>index.json        — { lastUpdated, skills: SkillIndexItem[] }
 *
 * The index document is upserted on every write and rebuilt from a bucket
 * listing when missing or unparsable (self-healing). Concurrent writers can
 * race the index read-modify-write; the rebuild path recovers from any
 * resulting drift, matching curator's production behavior.
 *
 * @aws-sdk/client-s3 is an optional peer — loaded lazily with the same
 * createRequire pattern as memory's @juspay/hippocampus so importing
 * NeuroLink core never requires the AWS SDK. Tests (and hosts with
 * pre-configured clients) inject a SkillS3ObjectOps implementation instead.
 */
import type { SkillDefinition, SkillIndexItem, SkillS3ObjectOps, SkillS3StorageConfig, SkillStore } from "../types/index.js";
export declare class S3SkillStore implements SkillStore {
    private readonly config;
    /** Test/host seam — omit to build ops from @aws-sdk/client-s3 lazily. */
    private readonly injectedOps?;
    private readonly prefix;
    private ops;
    /** Last parsed index + its ETag, revalidated with If-None-Match reads. */
    private cachedIndexDoc;
    private cachedIndexEtag;
    constructor(config: SkillS3StorageConfig, 
    /** Test/host seam — omit to build ops from @aws-sdk/client-s3 lazily. */
    injectedOps?: SkillS3ObjectOps | undefined);
    invalidate(): void;
    private getOps;
    private skillKey;
    private indexKey;
    /** Resources live beside the skill object: <prefix>skills/<id>/<path>. */
    private resourceKey;
    getResource(id: string, resourcePath: string): Promise<string | null>;
    get(id: string): Promise<SkillDefinition | null>;
    put(skill: SkillDefinition): Promise<void>;
    delete(id: string): Promise<void>;
    index(): Promise<SkillIndexItem[]>;
    private writeIndex;
    /**
     * Raw index.json read. Returns the body (with its ETag when available),
     * null body when the object is absent, or notModified when a
     * conditional read reported the cached copy unchanged.
     */
    private readIndexObject;
    /**
     * Read index.json (ETag-revalidated when the ops support conditional
     * reads — an unchanged index costs a 304, not a download); when missing
     * or unparsable, rebuild it from a listing of the skills/ prefix and
     * persist the rebuilt document (self-heal).
     */
    private readOrRebuildIndex;
}