/**
 * Wire-side compaction/projection for replayed session history.
 *
 * Stored `events_jsonl` blobs can grow to several megabytes because they
 * contain data the browser never renders:
 *
 *  - `tool_result.result.details.results` — the subagent's full internal
 *    transcript (`messages`, `systemPrompt`, `task`, `stderr`, …).
 *  - Hundreds of repeated `subagent_tool_progress` snapshots for the same
 *    `stepId`, each re-carrying full tool args and partial results.
 *  - Inline base64 screenshots (`{ type: "image", data }`) captured by the
 *    desktop-control tools. A single full-screen PNG is worth several MB of
 *    base64, and legacy rows carry them verbatim.
 *
 * This module performs a **projection at replay build time**. It never
 * mutates SQLite or the live agent stream; it only shapes the history that is
 * about to be serialized into `history_chunk` frames.
 *
 * The projection is intentionally best-effort:
 *  - Malformed JSONL lines are skipped.
 *  - Unknown events and every field the frontend renders are left untouched.
 */
import type { WireMessage } from "../server/wire.js";
/** Byte ceiling for individual preserved strings inside a projected event. */
export declare const MAX_PROJECTED_FIELD_BYTES: number;
/**
 * Strip threshold for an inline image `data`, measured in base64 CHARACTERS
 * (what travels as JSON), not decoded bytes — hence the `_CHARS` name.
 *
 * It mirrors `MAX_INLINE_IMAGE_BASE64_CHARS`, the real ingress/wire cap:
 * anything at or below that cap is renderable, so stripping it would only
 * lose images the user can still see. Anything above it could never have been
 * accepted by the relay in the first place.
 */
export declare const MAX_PROJECTED_INLINE_IMAGE_CHARS: number;
/** Marker appended when an oversized string is truncated. */
export declare const TRUNCATION_MARKER = "\n...[spectral truncated for history replay]";
/**
 * Parse and project a newline-delimited `events_jsonl` string.
 *
 * - Skips blank/malformed lines.
 * - Dedupes `subagent_tool_progress` by `stepId` (last occurrence wins).
 * - Re-joins the projected events into a JSONL string.
 */
export declare function projectEventsJsonl(eventsJsonl: string): string;
/**
 * Project an entire persisted history tail before it is chunked and emitted.
 *
 * Only assistant messages carry `events_jsonl`. Messages whose projection is
 * byte-identical to the input are returned by reference, so this is a no-op
 * for already-compact histories.
 */
export declare function projectHistoryForReplay(history: readonly WireMessage[]): WireMessage[];
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