## 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
## What changed
- Add a `SecurityRiskScore` rollout item containing a category and numeric score.
- Persist the item in both thread history modes while excluding it from model context, user-visible thread history, search text, forks, and reconstructed conversation history.
- Re-export the score type from the extension API.
## Testing
- Cover serialization, persistence and loading, thread history projection, session reconstruction, append planning, and memory filtering.
GitOrigin-RevId: 1926fe366aeaa75052708a6da589f45a38eefb52
## What changed
- Wrap response items with optional harness-owned metadata while keeping the persisted response payload shape backward compatible.
- Store compacted-history metadata in an aligned sidecar and reject malformed sidecars.
- Carry metadata through history normalization, compaction, resume, fork, truncation, migration, and rollout recording without sending it to model providers.
## Testing
- Cover legacy rollout compatibility, metadata serialization and validation, compaction retention, and resume/fork reconstruction.
GitOrigin-RevId: 17a6127c9048ff984cb4df4d97c0751a38c29f5f
## What changed
- Add `codex-history` for model-history and persisted-rollout domain types, including `RolloutItem`, `RolloutLine`, `CompactedItem`, and initial/resumed history state.
- Re-export the persisted types from `codex-rollout` and update consumers to use the new crate boundary instead of `codex-protocol`.
- Preserve existing rollout serialization, including legacy numeric compacted-window IDs.
## Testing
- Add `codex-history` tests for rollout JSON round trips, compacted-history compatibility, persisted history modes, and multi-agent version selection.
GitOrigin-RevId: 944daa9297ddd231d3aebbdcb05fff4adf8b4e1b
## Why
Reconstructing the latest model-visible context does not require replaying an
entire paginated rollout when a usable compaction checkpoint and the associated
completed-turn metadata are available.
## What changed
- Add `ThreadStore::load_latest_model_context` and `StoredModelContext` for
loading replay-ready model context independently of full thread history.
- Reverse-scan plain paginated JSONL rollouts until the newest safe bounded
suffix is found, while preserving canonical session metadata and chronological
replay order.
- Fall back to complete history for legacy or compressed rollouts and whenever
compaction or rollback records make a bounded cutoff unsafe.
## Testing
- Cover checkpoint selection, turn-metadata boundaries, agent messages,
contextual user fragments, and full-history fallbacks.
GitOrigin-RevId: 3572f4ecc7aa4099a6d9f0d3e72d0ef432cd9497
guinness-oai