Function buildHistoryCompactBlockFromSummary

packages/runtime/src/history-compact.ts:632–701

(input: {
  sessionId: string;
  foldedRuntimeEvents: readonly RuntimeEvent[];
  summary: string;
  highWaterName?: string;
  highWaterSeq?: number;
  maxSummaryEstimatedTokens?: number;
  sourceArchiveRefs?: readonly HistoryCompactSourceArchiveRef[];
  requestShapeHashBefore?: string;
  requestShapeHashAfter?: string;
  now?: number;
  charsPerToken?: number;
})

}

export function buildHistoryCompactBlockFromSummary(input: {
  sessionId: string;
  foldedRuntimeEvents: readonly RuntimeEvent[];
  summary: string;
  highWaterName?: string;
  highWaterSeq?: number;
  maxSummaryEstimatedTokens?: number;
  sourceArchiveRefs?: readonly HistoryCompactSourceArchiveRef[];
  requestShapeHashBefore?: string;
  requestShapeHashAfter?: string;
  now?: number;
  charsPerToken?: number;
}): HistoryCompactBlock {
  const charsPerToken = input.charsPerToken ?? 4;
  const highWaterName = input.highWaterName ?? 'history-compact-high-water';
  const createdAt = Math.max(input.now ?? 1, ...input.foldedRuntimeEvents.map((event) => event.ts));
  const highWaterSeq = input.highWaterSeq ?? createdAt;
  const coverage = deriveHistoryCompactCoverage(input.foldedRuntimeEvents);
  const sourceRefs: SynthesisSourceRef[] = input.foldedRuntimeEvents.map((event) => ({
    kind: 'runtime_event',
    sessionId: event.sessionId,
    turnId: turnKey(event),
    runtimeEventId: event.id,
    role: event.role,
    contentKind: event.content?.kind ?? 'none',
  }));
  const maxSummaryTokens = finitePositive(input.maxSummaryEstimatedTokens) ?? 768;
  const summary = boundText(
    input.summary,
    Math.max(80, maxSummaryTokens * Math.max(1, charsPerToken)),
  );
  const blockDraft = {
    version: 1,
    sessionId: input.sessionId,
    highWaterName,
    highWaterSeq,
    coverage,
    summary,
  };
  const sourceArchiveRefs =
    input.sourceArchiveRefs?.filter(isValidHistoryCompactSourceArchiveRef) ?? [];
  const block: HistoryCompactBlock = {
    kind: 'maka.history_compact_block',
    version: 1,
    blockId: stableHistoryCompactBlockId(blockDraft),
    sessionId: input.sessionId,
    createdAt,
    highWaterName,
    highWaterSeq,
    coverage,
    summary,
    limitations: [
      'Host-owned replay-time summary of older RuntimeEvents.',
      'Original RuntimeEvents are not mutated; request raw evidence or history search when exact wording matters.',
      ...(sourceArchiveRefs.length === 0
        ? [
            'No archive refs are attached; source coverage is by RuntimeEvent ids and content hashes.',
          ]