Next release: thread lifecycle, storage and source control

[Tryanks]

Plan of record for the next release: bound thread history growth, give threads a real lifecycle, and add source-control (PR) support across forges.

Research inputs (Sep 2026): T3 Code origin/main f5ef0ddb9, openai/codex 7342991 plus the Codex desktop app bundled in ChatGPT.app 26.917, and read-only measurements of the maintainer's own data (Tcode data dir 9.2 GB, 2,716 thread logs; ~/.codex/sessions 6.9 GB).

Decisions

• Storage: no SQLite. Metadata and indexes go in redb (already in Cargo.lock, zero new crates); event bodies stay in files. Compaction first, engine second.
• Compression: flate2 (already in the tree), not zstd.
• Automatic lifecycle: auto-settle only. Auto-archive is removed; archive is always explicit, because it now moves logs, calls provider-native archive and cleans up worktrees. Rule: automatic transitions must be losslessly reversible.
• Settle stops the provider session (as in T3 Code).
• Snooze and pinned are in scope.
• Archive semantics follow the Codex app. Provider-native archive/delete is used only where the protocol has it (Codex, OpenCode, ACP when advertised). No native delete is synthesized for Claude Code or pi.
• Process lifetime follows the provider's prompt-cache TTL measured from the last turn, not view time. No keep-alive pings.
• PRs: linked PRs and an Open PR action across GitHub, GitLab, Gitea, Forgejo, Bitbucket and Azure DevOps, self-hosted included. No model-facing MCP tool for linking PRs. The Open PR action works during a run in two modes: the host runs it at turn end, or it sends a visible message to the agent. "Merge when CI passes" uses the forge's native auto-merge.

Work items

Phase 0: bugs and batch commands

• Unarchived threads are re-archived by the next auto-archive sweep #515 Unarchived threads are re-archived by the next auto-archive sweep (resolved by Thread lifecycle: make Settled a real state and remove auto-archive #526 if that lands first)
• Startup orphan sweep force-removes worktrees the user chose to keep #516 Startup orphan sweep force-removes worktrees the user chose to keep
• Removing a deleted thread's worktree also deletes its forks' working directory #517 Removing a deleted thread's worktree also deletes its forks' working directory
• Deleting a thread leaves its descendant threads with a dangling parent #518 Deleting a thread leaves its descendant threads with a dangling parent
• Archive confirmation wrongly says archiving cannot be undone #519 Archive confirmation wrongly says archiving cannot be undone
• External import races the store writer on sessions.json #520 External import races the store writer on sessions.json
• Batch thread lifecycle commands instead of one index rewrite per thread #521 Batch thread lifecycle commands

Phase 1: storage

• Storage: compact thread logs at turn end #522 Compact thread logs at turn end (about −66% of stored bytes, no new dependency)
• Storage: replace sessions.json with a redb index #523 Replace sessions.json with a redb index
• Storage: turn index so long threads open without parsing the whole log #524 Turn index, tail file, windowed reads, cold-log compression (depends on Storage: compact thread logs at turn end #522, Storage: replace sessions.json with a redb index #523)
• Client: bound history memory for visited threads #525 Bound client history memory

Phase 2: lifecycle

• Archive: align with the Codex app (log move, provider-native archive, undo) #529 Archive aligned with the Codex app (depends on Batch thread lifecycle commands instead of one index rewrite per thread #521)
• Worktrees: host-owned ownership and an archive lifecycle (snapshot, transfer, keep-count) #530 Host-owned worktree ownership and archive lifecycle (depends on Startup orphan sweep force-removes worktrees the user chose to keep #516, Removing a deleted thread's worktree also deletes its forks' working directory #517, Archive: align with the Codex app (log move, provider-native archive, undo) #529)
• Providers: tie process lifetime to the prompt-cache TTL #531 Tie provider process lifetime to the prompt-cache TTL
• Thread lifecycle: make Settled a real state and remove auto-archive #526 Settled as a real state; remove auto-archive
• Thread lifecycle: snooze #527 Snooze (depends on Thread lifecycle: make Settled a real state and remove auto-archive #526)
• Thread lifecycle: pinned threads #528 Pinned threads (depends on Thread lifecycle: make Settled a real state and remove auto-archive #526)

Phase 3: source control

• Source control: forge detection and linked pull requests across forges #532 Forge detection and linked pull requests
• Source control: Open PR action usable during a run, with merge when CI passes #533 Open PR action usable during a run, with merge when CI passes (depends on Source control: forge detection and linked pull requests across forges #532)
• Source control: settle threads and clean up worktrees when linked PRs merge #534 Settle threads and clean up worktrees when linked PRs merge (depends on Thread lifecycle: make Settled a real state and remove auto-archive #526, Worktrees: host-owned ownership and an archive lifecycle (snapshot, transfer, keep-count) #530, Source control: forge detection and linked pull requests across forges #532)

Coordination

• Several of these change the protocol (new batch, settle, snooze, pin and PR commands and events). They should land after the in-flight perf/remote-wire-bytes work, which bumps PROTOCOL_VERSION to 6, and batch their own bumps where practical.
• guivieiras/tcode has unmerged work that overlaps. Most of it is on local/integration, last pushed 2026-09-17, with no open PR:
  • last_user_message_at and thread sort by last user message (45e74fc, 68a5f3d): overlaps Thread lifecycle: make Settled a real state and remove auto-archive #526 and Storage: replace sessions.json with a redb index #523.
  • A sidebar thread-row rewrite and a "Mark completed" marker (874fefd, 9cd8805, cf68c7e): overlaps Thread lifecycle: make Settled a real state and remove auto-archive #526, Thread lifecycle: snooze #527 and Thread lifecycle: pinned threads #528.
  • Reusing existing worktrees and named worktrees (241616d, 8556ded): overlaps Removing a deleted thread's worktree also deletes its forks' working directory #517 and Worktrees: host-owned ownership and an archive lifecycle (snapshot, transfer, keep-count) #530.
  • Queued-message drawer, and editing and removing queued messages (219d046, c58bf81): overlaps Source control: Open PR action usable during a run, with merge when CI passes #533.
  • An offline T3 Code importer with an optional rusqlite dependency (5ee044b and follow-ups): overlaps External import races the store writer on sessions.json #520 and Storage: replace sessions.json with a redb index #523.