fix(agents): refuse codex resume-adopt explicitly + document why#125
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… downgrading
Resume-adopt (claude --resume under a PTY) is claude-only because the
liveness guard that prevents resuming a *live* session — and corrupting its
transcript via a second writer — relies on claude's pid-file
(~/.claude/sessions/<pid>.json + kill -0). Codex has no equivalent: its
rollout JSONL carries no pid/lock, so "idle" could only be guessed from
mtime, which isn't safe. The codex CLI *does* support `codex resume <id>`;
the blocker is the missing liveness signal, not the capability.
Previously POST /api/agents/pty/start {agent:"codex", resumeSessionId}
passed the claude-only liveness check (the id isn't in the claude set), then
PtyAgent.start dropped the resume args (gate was kind==="claude-code") and
spawned a *fresh* codex session — so "resume X" silently became "new
session". Now it's refused honestly:
- PtyAgent.start throws for resumeSessionId on a non-claude agent.
- POST /api/agents/pty/start returns 400 (clearer than the generic 503).
codex adopt-at-launch (a fresh `lisa agents pty codex "<task>"`) is unaffected.
Docs: PTY_AGENTS.md gains "Why codex resume-adopt isn't supported (yet)"
(with unblock conditions); IOS_COMPANION_PLAN.md §4 records the investigation
and the explicit refusal.
Verified: npm run typecheck && npm run build && npm test -> 804 pass, 1 skip
(the real-node-pty round-trip, which can't spawn under Node 26).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Resume-adopt (
claude --resumeunder a PTY) is claude-only because its non-bypassable liveness guard — which refuses to resume a live session and corrupt its transcript via a second writer — relies on claude's pid-file (~/.claude/sessions/<pid>.json+kill -0).I checked codex parity: the codex CLI does support
codex resume <id>, but it leaves no equivalent liveness signal (its rollout JSONL carries no pid/lock), so "idle" could only be guessed from mtime — unsafe on a transcript-corruption surface. codex also isn't installed in this environment and node-pty can't spawn under Node 26, so a speculative path couldn't be verified end-to-end. So it's documented as deliberately unsupported, with the unblock conditions.While doing so I found + fixed a latent footgun:
POST /api/agents/pty/start {agent:"codex", resumeSessionId}used to pass the claude-only liveness check and then silently start a fresh codex session (the resume id was dropped) — "resume X" became "new session". Now:PtyAgent.startthrows forresumeSessionIdon a non-claude agent.codex adopt-at-launch (a fresh
lisa agents pty codex "<task>") is unaffected. The CLI/iOS/GUI never request codex resume, so this only tightens the direct-API path.Docs
docs/PTY_AGENTS.md: new "Why codex resume-adopt isn't supported (yet)" section.docs/IOS_COMPANION_PLAN.md§4: records the investigation + explicit refusal.Verification
npm run typecheck && npm run build && npm test→ 804 pass, 1 skip (the real-node-pty round-trip, which can't spawn under Node 26). The refusal is unit-tested insrc/agents/pty.test.ts.🤖 Generated with Claude Code