/**
 * Artifact Store Types (canonical location)
 *
 * Types for the MCP large-output artifact storage system.
 * When mcp.outputLimits.strategy = "externalize", oversized MCP tool outputs
 * are stored as artifacts and the model receives a compact surrogate instead.
 *
 * @module types/artifactTypes
 */
/** Metadata recorded alongside a stored artifact. */
export type ArtifactMeta = {
    /** Tool name that produced the output. */
    toolName: string;
    /** MCP server ID. */
    serverId: string;
    /** Session that triggered the tool call (optional). */
    sessionId?: string;
    /** Serialized byte size of the full payload. */
    sizeBytes: number;
    /** Whether the payload is valid JSON or plain text. */
    contentType: "json" | "text";
    /** Unix epoch ms when the artifact was created. */
    createdAt: number;
};
/** Lightweight descriptor returned after a successful ArtifactStore.store(). */
export type ArtifactRef = {
    /** UUID v4 — stable identifier used in surrogate results and metadata. */
    id: string;
    /** First N characters of the payload (for surrogate headers). */
    preview: string;
    /** Full serialized byte size. */
    sizeBytes: number;
    /** Stored metadata. */
    meta: ArtifactMeta;
};
/**
 * Pluggable storage contract for externalized MCP tool outputs.
 *
 * Default backend: LocalTempArtifactStore (filesystem, single-process).
 * Future backends can implement this interface for S3, Redis blobs, etc.
 */
export type ArtifactStore = {
    /**
     * Persist a payload and return a lightweight reference.
     * @param payload  Serialized tool output (JSON string or plain text).
     * @param meta     Descriptor without `createdAt` (assigned internally).
     */
    store(payload: string, meta: Omit<ArtifactMeta, "createdAt">): Promise<ArtifactRef>;
    /**
     * Retrieve the full payload by artifact ID.
     * Returns `null` if the artifact is not found or has been cleaned up.
     */
    retrieve(id: string): Promise<string | null>;
    /** Delete a single artifact. No-op if the ID does not exist. */
    delete(id: string): Promise<void>;
    /**
     * Delete all artifacts older than `olderThanMs` milliseconds.
     * Returns the number of artifacts deleted.
     */
    cleanup(olderThanMs: number): Promise<number>;
    /** Generate a short preview string from a serialized payload. */
    generatePreview(payload: string): string;
};
/**
 * In-memory index row tracked by LocalTempArtifactStore.
 * Combines metadata with the on-disk path.
 */
export type IndexEntry = ArtifactMeta & {
    path: string;
};