Resuming a Build

Resuming a build

ctrl+r on an executed version in the picker starts the agent session that built it back up. You are back in the conversation that wrote the code, instead of explaining the code to a stranger.

planx                 # → for the plan's versions, ctrl+r on the green one

What is recorded

planx execute writes four things onto the version at the moment the agent picks it up:

Recorded	Where it comes from
The session id	--session-id, passed by the executing agent
The agent	--agent, or PlanX walking its own process tree
Its launch line	The same process walk
The plan's directory	The directory the plan was captured in

The process walk is why the agent does not have to be told: how the tab was started is a fact about PlanX's own parents, not something the agent knows about itself. PlanX reads ps up to five hops, past shells and runtimes like node or npx, and stops at claude or codex.

What is replayed

The recorded launch line, verbatim, minus the flags that name a session — those would collide with the selector PlanX is adding.

Agent	The command
Claude Code	claude <recorded flags> --resume <session-id>
Codex	codex <recorded flags> resume <session-id>

Codex takes resume as a subcommand, so its flags go in front of it.

It runs in the plan's own directory. If that directory is gone, PlanX says so and runs where you are instead.

The whole command is printed before it runs, flags included, so what was started and what it was granted is on the scrollback above the agent's first frame.

No prompt goes with it

Resuming sends the agent nothing. The first thing it hears is whatever you type next.

That is deliberate: re-sending /planx execute would have the agent re-read the plan and redo work it has already done. You are resuming the conversation that implemented the plan, and what happens next is yours.

When the key is not offered

ctrl+r appears only on a row that can produce a launch.

• No session id recorded. The agent that built it never passed one — a version built before this feature existed, or by an agent that names no session.
• An agent PlanX cannot start. Only claude and codex are launched directly; anything else is a shell in between, and reviving a session with a guess is not something PlanX attempts.
• A plan row with two builds behind it. The plan row offers ctrl+r only where exactly one of its versions qualifies. Press → and pick the version.

Without the key, resume the session with your agent's own command — claude --resume <id> or codex resume <id> — or simply start a new session and hand it the plan with /planx execute <id> v<n>.

When the binary is missing

If the agent is not on your PATH, PlanX says so and prints the line it was going to run, under Resume it yourself. Nothing is lost — the command is there to copy once the binary is back.

The green rows

A version that was executed is tagged executed and painted green in the picker. Its plan row is green too, until the plan gains a version newer than the one that was built: what was executed is no longer the plan, so the plan row goes back to normal and the green stays on the child row, which is where the history is.