l0ng-ai 65892e155e feat(agents): fork an agent session, and copy its session id ...

A coding-agent conversation is a single thread: to try a risky direction you
either lose the one that got you there, or you don't try it. Every agent tty7
resumes already knows how to branch — `codex fork <id>`, `claude --resume <id>
--fork-session`, `opencode --session <id> --fork`, `grok --resume <id>
--fork-session` — but nothing in tty7 reached them, so the capability was
invisible from the terminal that already knows every pane's session id.

Fork is a per-agent capability beside the existing resume table
(`CLIAgent::fork_command`), not a Codex special case: it is the same `match
self` shape, it reuses the same id validation and the same launch-flag replay,
and four installed agents qualify today. Every command was checked against that
CLI's own `--help`; agents with no fork tty7 could verify return `None` and are
never offered the action, since a guessed flag shape would only ever produce a
usage error in the pane.

Flag replay needed one correctness fix to survive this. A forked pane's own
argv *is* a fork command, so relaunching it would replay the stale subcommand
and id (`codex fork <old>` → an old id as a positional prompt) or double the
modifier (`--fork-session --fork-session`). `codex fork` now sheds its
subcommand exactly as `codex resume` did, and `--fork-session` / `--fork` join
their agents' stale session-targeting lists. That also settles restore: a forked
pane restores through `resume_command`, which now drops the fork flag — a
restart continues the fork rather than branching it again.

Placement follows where the user asked from. A pane-level ask is spatial, so
the pane right-click menu offers Split Right / Left / Down / Up (pane splits
gained a `before` slot for the Left/Up half, which the tree had no way to
express). A tab-level ask isn't, so the tab context menu — inherited verbatim by
the sidebar rows, which is where the request came from — opens the fork in a new
tab with no placement question. The bare action behind the palette, the File
menu and Settings → Keybindings takes the tab-level meaning.

The three ways a fork can't run all surface rather than no-op: no session id
yet (hooks not installed) and a remote pane (the command would shell the *local*
agent) render the row disabled instead of hiding it, so the capability stays
discoverable, and the action paths that have no row to grey out say so in a
notification. Forking mid-turn is allowed but announced — agents fork from the
persisted transcript, so the turn in flight is absent from the copy — and the
parent is untouched either way.

Copy Session ID sits beside Copy Working Directory. Codex has no
copy-or-duplicate subcommand, so "copy the session" is the id: paste it into
`codex resume`, a bug report, or another tool.

Deliberately not built: any reading or writing of an agent's own session files.
tty7's exposure stays the public CLI contract plus the hook payload's session
id, so a change to Codex's rollout format or its version-numbered SQLite index
costs at most a visible shell error. Forked tabs also look exactly like their
parent, by decision — "Rename Tab" is the answer.

Closes #211

2026-07-29 00:12:07 +08:00

..

tty7-core

feat(agents): fork an agent session, and copy its session id

2026-07-29 00:12:07 +08:00

tty7-server

fix(workspaces): make a handover atomic and stop two stores clobbering one file

2026-07-28 21:54:23 +08:00