[cdalar]

Why

onctl claude still had boxctl's first model: one long-lived claude-<project> box, the project copied once and reused forever. boxctl moved on 2026-10-14 to a fresh box per run, and with the prebuilt claude-agent image (#1234) a new VM is cheap enough on every provider, ac included.

Follows #1234 (merged); the first PR for this branch, #1235, was closed automatically when that base branch was deleted.

What

• A new box per run, named <project>-<slug>-<id> (cmd/boxname.go, ported from boxctl: the slug from --prompt, else an adjective-noun pair; 40-character cap; a taken name gets a new id, checked against listClaudeVMs).
• Cloned, not copied: a repository with an origin is cloned on the box (cloneURL turns any GitHub origin into https for the credential helper) onto branch onctl/<slug>-<id>. The GitHub token is forwarded for the clone the way it is for an attach, over a connection of its own (runWith, forwardGitHub shared with attachClaude). --github store stores before the clone. A project without an origin is copied as before.
• Deleted when Claude exits, after fetchBox (the body of onctl claude fetch, now reusable) brings branches and a wip snapshot here as box/*. A failed fetch keeps the box and says how to fetch and destroy by hand. Setup failure or Ctrl-C (signal.NotifyContext) deletes it too; a failure inside openClaudeBox deletes the box only if it got made (discardIfMade).
• Detaching keeps it: after the attach returns, a still-running session means the box is kept, with the --box line to come back.
• --keep / -k restores the project box, cloned onto onctl/<project> the first time; --box, --detach, --task and --own-box imply it. --repo is unchanged (its own box, kept) and listed as a follow-up.
• herdr: an ephemeral session's pane runs sh <cmd>; herdr server stop, so the attached client returns when Claude exits. A kept box's server lives on.
• Help text and README describe the new default. docs/plans/claude-ephemeral-and-ac-image.md is the plan.

Not ported from boxctl: reconnect-on-drop, labels, goals, the 1 GiB copy cap.

Tests

TestTextSlug, TestGenerateName, TestEphemeralRun, TestCloneURL, TestSaveBoxWorkWithNothingToSave, TestRunWithArgs, TestHerdrStartEphemeral, and the "already exists" case in TestCloneScript. go test ./cmd/ green.

To verify by hand (ac, on this Mac, from a GUI terminal)

onctl -p ac claude --prompt "add a README line" → a container <repo>-add-readme-line-xxxx on branch onctl/add-readme-line-xxxx; quitting Claude prints "Fetching…", leaves box/onctl/… locally and removes the container. Detaching instead keeps it with the --box hint. --keep gives claude-<repo> as before.

🤖 Generated with Claude Code

https://claude.ai/code/session_01FGfFdYSzrrKe3ySAVMPSNR

[codecov]

Codecov Report

❌ Patch coverage is 33.33333% with 116 lines in your changes missing coverage. Please review.
✅ Project coverage is 47.49%. Comparing base (60b8a26) to head (662daf5).

Files with missing lines	Patch %	Lines
cmd/claude.go	6.77%	55 Missing ⚠️
cmd/claudeephemeral.go	6.81%	41 Missing ⚠️
cmd/boxname.go	78.26%	10 Missing ⚠️
cmd/claudecopy.go	59.09%	9 Missing ⚠️
cmd/claudegit.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1236      +/-   ##
==========================================
- Coverage   47.71%   47.49%   -0.23%     
==========================================
  Files          78       80       +2     
  Lines        9176     9326     +150     
==========================================
+ Hits         4378     4429      +51     
- Misses       4798     4897      +99     

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