## Why
Clients starting delegated work need to attribute descendant turns to the original turn and retain that attribution through completion and history reads.
## What changed
- Accept optional `parentTurnId` and `rootTurnId` in `turn/start`, and expose `rootTurnId` on returned turns and lifecycle notifications.
- Default new turns to their own root when none is supplied. Preserve the active turn's root when steering, ignoring incoming lineage fields.
- Carry root IDs through completion, interruption, recovery, and fork boundaries, and persist them for paginated history reads. Leave unknown roots null in older history.
- Update protocol schemas and generated TypeScript and Python bindings.
## Testing
Extend coverage for default and explicit roots, steering without changing lineage, interrupted and recovered turns, history reads after restart in both history modes, nested fork pagination, and compatibility with older database writers.
GitOrigin-RevId: f1a570a12bd11742929fd2e8b017e5d35aa07dcb
## What changed
- Persist producer-recorded item start and completion times in thread history, preserving existing non-null values on updates.
- Return nullable `startedAtMs` and `completedAtMs` Unix millisecond timestamps from `thread/items/list`, and update the generated schemas and TypeScript and Python types.
- Leave timestamps unknown for existing rows and older writers.
## Testing
Add coverage for exact timestamp persistence, protocol round trips with present and missing timestamps, paginated item responses, and compatibility with older database writers.
GitOrigin-RevId: 894853481085782ff54db1704799e41446d15e51
## Why
Clients need a bounded view of realtime conversations that preserves the order of speech, agent work, and turn lifecycle events without loading the full thread history.
## What changed
- Persist realtime session boundaries, transcript segments, and promoted agent items in paginated thread rollouts.
- Add the experimental `thread/timeline/list` API to page ordinary items, realtime items, and turn boundaries in canonical rollout order. Include `activeRealtimeSessionAtPageStart` so each page can be rendered independently.
- Emit typed `thread/realtime/item/started`, `thread/realtime/item/transcript/delta`, and `thread/realtime/item/completed` notifications around durable realtime items.
- Keep the existing `thread/items/list` response and legacy thread history behavior unchanged.
## Testing
- Cover mixed timeline pagination, realtime-session state at page boundaries, rollout replay, subagent history prefixes, transcript streaming, steering, and promoted agent artifacts.
GitOrigin-RevId: faa2c420192d63e060e8fb32446e3c797422656e
## Why
Persisted item snapshots can be updated after their initial projection while retaining their creation order. Callers need a way to read those updates incrementally without replaying every item.
## What changed
- Track the rollout ordinal of each item's latest snapshot separately from its creation ordinal.
- Let thread-store callers filter items after an exclusive update watermark and sort pages by either creation or update ordinal.
- Keep existing app-server reads creation-ordered, reject incremental reads across forked lineages, and preserve compatibility with older writers.
## Testing
- Cover update-watermark filtering, pagination, sort directions, per-turn reads, cursor validation, forked lineages, migration compatibility, and refreshed item snapshots.
GitOrigin-RevId: d57de849abec27f788e9c384dbff073a0aca1053
## What changed
- Store the starting byte offset and terminal ordinal and byte offset for each turn projected into SQLite.
- Advance offsets across blank and rejected physical lines while leaving incomplete trailing lines for the next materialization pass.
- Stop later rollout records from changing a turn after it reaches a terminal state.
## Testing
- Cover active and completed turn positions, trailing partial lines, skipped invalid lines, subagent history prefixes, and records received after terminal state.
GitOrigin-RevId: a7da2f0b00c0bf47b841db874c79a0d495c18acd
## What changed
- Add the experimental `thread/searchOccurrences` app-server method for case-insensitive literal search across visible user messages and final assistant messages without replaying the thread.
- Return paginated snippets with UTF-16 match ranges and `thread/turns/list` cursors for navigating to each matching turn.
- Index persisted item types to efficiently select searchable messages from paginated thread history.
## Testing
- Add an app-server integration test covering pagination, steering messages, final-answer selection, Markdown normalization, and UTF-16 offsets.
GitOrigin-RevId: e80160e0f83eb4e5db8de862307085093bee362b
## What changed
- Project durable paginated rollout records into rebuildable SQLite tables for turns, items, and projection progress while keeping JSONL as the source of truth.
- Add cursor-based local reads for turn summaries and thread or per-turn items, including archived-thread and history-mode validation.
- Serialize writes, shutdown, and deletion per thread so projection updates cannot race cleanup, and remove projected rows when a thread is deleted.
- Preserve stable item ordering while updating repeated snapshots and expose structured turn error details.
## Testing
- Cover projection, snapshot updates, summary recovery, pagination, failure handling, shutdown flushing, legacy-mode rejection, and deletion races.
GitOrigin-RevId: 34533185ece7f1f5690004c7f12b0f1f34dc2640
## Why
Paginated thread history needs its own SQLite database to avoid adding lock
contention to the main state store.
## What changed
- Add the `thread_history_1.sqlite` path and migration scaffolding.
- Create tables and pagination indexes for projected turns and items, plus a
per-thread projection checkpoint.
- Register the database with runtime diagnostics, Bazel inputs, and database
telemetry.
GitOrigin-RevId: d194310835f1df2a2a29c7827d77ca37eabbd0a3
Eddie Chen