Resume In Place
Front-End Run Restart
A stopped owning monitor can restart the same run without leaving the terminal.
0 milestones 5 tasks 11 agents
2 plan 4 execute 5 review
192k peak context
155k median execute
1h 27m total 11m 47s per task
3m 17s plan 41m 33s execute 9m 58s review
37 edits 294 commands
codex harness
This run turns a dead-end monitor into a control surface for continuing the same work. The cut starts at the owner lifecycle contract, adds a visible resume action, preserves the terminal session across the restarted engine, then locks the behavior down with regression coverage and docs that separate it from shell resume and live manual repair.
How this walkthrough is structured
Feature
What did the run build and ship?
Gantry now has a standing owner-only Resume in place path that re-acquires the run lock, resumes the same identity, keeps the terminal session open, and documents when to use it.
Build
How did Gantry structure the work?
The decomposition kept the owner contract, TUI action, session reset, lifecycle coverage, and docs in separate fresh-agent slices, with the final documentation slice taking an extra gate pass after review.
Owner Restart Contract
2 agents 23m 16s wall time 192k peak context
The owner loop still stands in `src/main.rs`. `FrontEndExit::RestartSameRun` is distinct from normal quit, attached front-ends are rejected if they try to request it, and a restarted owner session becomes `PlanSource::Resume` for the same run name. The current code has since been renamed from Gantry to Gantry, but the lock-release and attach-race behavior from this slice remains present.
This first slice carried the backend boundary the later UI work would consume. Its brief was narrow enough for one agent because it stayed inside process ownership and exit disposition: add a restart result, release the existing owner guard, and re-enter through the ordinary lock path. The gate and review stayed green, which says the contract fit the existing live-owner routing without forcing a re-plan.
Resume Action
1 agents 11m 47s wall time 64k peak context
The TUI still registers `run.resume_in_place` with the visible label and binding, and the Gantry menu includes it as a disabled-by-default run item whose state is recomputed from the app. `AppState` still carries the restart flag, and dispatch turns the owner action into a `TuiExit::RestartSameRun` result. Current tests keep the menu path, key path, live-run disablement, attached-front-end disablement, and neighboring controls distinct.
The second slice could focus on the monitor surface because the backend restart disposition already existed. Its job was to expose a real run control with consistent menu, key, help, and enabled-state behavior while leaving quit, abort, detach, and prompt answering as separate actions. It also passed without repair, showing the UI boundary was small enough to wire through shared action machinery in one pass.
Session Continuity
2 agents 14m 8s wall time 155k peak context
The live tree still has a reusable `TuiSession` owned across the front-end owner loop, with cleanup deferred until the loop finishes. `ResumeInPlaceStatePolicy` remains documented in code, and `reset_for_resume_in_place` carries chat transcript and pane state while clearing cards, roster, stop state, prompts, stats, metadata, and command queues for the fresh event stream. Tests cover both the preserved chat state and the rehydration of fresh run status.
This slice took the trigger from the prior work and handled the experience between engine sessions. The brief asked for the terminal to remain initialized while the old engine stops and the resumed engine starts, plus an explicit state policy for what survives. The run stayed green, and the chosen policy reset run-derived projections while preserving the assistant-facing part of the session.
Lifecycle Regression Coverage
2 agents 9m 44s wall time 114k peak context
The current owner session code still drops the bound pattern invocation on an in-place restart, so the resumed engine uses the stored run footprint instead of replaying the original pattern flags or map width override. Regression tests in `src/main.rs` and `src/tui/mod.rs` still exercise stopped owners, completed owners, ordinary shell resumes, single-session quits, and attached restart errors. This is the part that makes the visible control behave like resume rather than a hidden rebuild.
After the implementation slices, this sprint was scoped as hardening over the lifecycle edges rather than a new feature surface. It tightened the distinction between in-place restart, ordinary shell resume, completed-owner restart, stopped-owner restart, and attached-front-end rejection. The boundary stayed green, and the production change it added was a small selector so restarted sessions read persisted run state rather than the original invocation.
Docs and Stale Diagnosis
2 agents 11m 2s wall time 131k peak context
The documentation now explains Run to Resume in place and the binding as the stopped-owner TUI surface, while `gantry resume` remains the shell and headless path. The lifecycle guide describes sequential ownership, the fresh resumed engine, the preserved assistant pane, and the reset run projection. The superseded assistant report is archived with its still-useful observations, although some original plan files from the run have since been retired from the live tree.
The final slice followed the code so it could describe shipped behavior instead of guessing at the state policy. Its brief was mostly editorial: document front-end resume, keep shell resume separate, archive the stale assistant diagnosis, and leave unrelated merge questions out of scope. Review led to another gate pass here, locating the only recorded stress at the documentation and cleanup boundary rather than in the core restart path.