## 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
Another Codex process can write, archive, or compress a rollout while startup
migration is inspecting it. This can leave a discovered path stale or make an
in-progress rollout look empty or busy.
## What changed
- Wait for rollout maintenance to finish before starting background migration.
- Re-read empty rollouts under their writer lock and retry busy rollouts on a
later startup.
- Find archived or compressed rollouts again when their paths change after
discovery, while keeping terminal failures from blocking the startup cursor.
## Testing
Added coverage for maintenance contention, writer-owned empty rollouts, busy
rollout retries after archive and compression moves, permanent failure skips,
pending recovery, and paths that move after discovery.
GitOrigin-RevId: 9708f212f2bbff88bd47a01ec4872bf6ce9af535
## Why
Rollout migration outcomes expose free-form error messages, making failures hard to group without parsing text.
## What changed
- Add a serialized `RolloutMigrationFailureReason` to failed outcomes and classify failures across reading, conversion, SQLite materialization, publishing, and recovery.
- Add the failure reason as a low-cardinality tag on per-thread migration telemetry.
## Testing
- Cover missing SQLite metadata and invalid session metadata classifications.
GitOrigin-RevId: 2bff98483b484f4d02b72d52f39950ff99ebe429
## Why
Legacy threads and paginated threads read their displayed names from different metadata. Moving a rollout to paginated history must carry over its legacy-visible name so renamed threads do not lose it.
## What changed
- Load legacy indexed names once for an apply run.
- When promoting a thread, preserve an existing canonical name or copy its distinct legacy title, falling back to the legacy name index.
- Repair missing names when migration encounters an already-paginated rollout.
## Testing
Added migration tests covering preservation from both legacy name sources and repair on a rerun.
GitOrigin-RevId: 5fc526570b1cf358a159ef174c159ac091ccc40f
## 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
## What changed
- Add `codex migrate-rollouts` with dry-run inspection by default, explicit `--apply`, thread filtering, optional I/O throttling, progress output, and JSON or verbose reports.
- Add the disabled-by-default `background_paginated_rollout_migration` feature to migrate legacy local sessions at startup before rollout compression begins.
- Persist a migration cursor and skipped-file fingerprints so later startups avoid full rescans while retrying changed files and recovering pending migrations.
- Coordinate migration with live writers and emit metrics for manual and startup runs.
## Testing
- Cover startup cursor advancement and lookback, pending migration recovery, live-writer coordination, changed empty rollouts, and progress reporting.
GitOrigin-RevId: 276ac506c50ebec5140fd319faca1bb998172061
## Why
Legacy rollouts can contain historical rollbacks, compaction checkpoints, and
subagent copies of parent history. Migrating those records verbatim can change
the visible conversation or the model context used when a thread resumes, and
can retain large amounts of duplicated subagent history.
## What changed
- Plan and replay historical rollbacks by logical turn, preserving surviving
lifecycle events and the correct compaction anchor for future resumes.
- Migrate subagent rollouts from a safe bounded replay when possible and record
the history boundary so copied parent context is not projected as child turns.
- Include archived and compressed rollouts while keeping their storage form and
location intact.
- Tolerate malformed, partial, oversized, and empty JSONL records during the
migration scan.
## Testing
Add coverage for rollback and compaction combinations, subagent replay bounds,
archived and compressed rollouts, recovery, concurrent maintenance, and damaged
JSONL input.
GitOrigin-RevId: 3948e16d43f75df8571b0a92af12a181d1d08fdf
## What changed
- Add `LocalThreadStore::migrate_rollouts` with dry-run and apply modes,
optional thread selection, throughput limiting, and per-rollout outcomes.
- Canonicalize legacy JSONL records into paginated history while preserving
model-visible conversation context, including compressed rollouts and copied
fork history.
- Publish replacements atomically and journal migrations so interrupted SQLite
projections can be recovered. Coordinate migration with rollout compression
and skip rollouts with active writers.
- Make paginated history a one-way SQLite promotion so stale metadata cannot
downgrade a migrated thread.
## Testing
- Cover legacy record normalization, dry runs, idempotency, malformed input,
compressed rollouts, active writers, interrupted migration recovery, and a
cold app-server resume after migration.
GitOrigin-RevId: b9991b659f28ebb52da39ce62e8b4e0bae2ba2bb