fix(cloud): start the agent session on --no-attach

[madarco]

Problem

On cloud providers (daytona/hetzner/vercel/e2b), agentbox claude/codex/opencode --no-attach and agentbox fork (which maps background mode to --no-attach) created the box but never started the agent. The agent's tmux session is created lazily by the attach step, so skipping attach skipped the agent entirely — the box came up empty.

This contradicts the documented --no-attach behavior: "create the box and start the agent session, but do not attach (background mode)." Docker was always correct (it creates the session before the attach check).

Root cause

The bare commands and fork funnel into cloudAgentCreate, which returned early on attach === false before any session was created. The three <agent> start subcommands had the same gap and even printed "cloud agent sessions are started lazily on attach" and returned without starting anything.

Fix

• _cloud-agent-create.ts — on attach === false, call cloudAgentStartDetached(...) (the same helper the -i queue worker uses) to start a detached tmux session and verify it stayed up (fail-loud on immediate exit / credential rejection), instead of returning early.
• claude.ts / codex.ts / opencode.ts start subcommand cloud branches — resolve args (skip-perms, resume teleport) first, then start the detached session in background mode rather than printing the lazy no-op message.

Cloud now matches docker on every path. No docs change needed — the --no-attach help text already describes the now-correct behavior.

Verification

• typecheck + lint clean; cloud-attach / attach-parse tests pass (18/18).
• Docker --no-attach (regression guard): box created, claude tmux session live with the TUI running.
• E2B --no-attach (the previously broken path): box created, process exits 0, tmux has-session -t claude confirms a live, logged-in Claude TUI — where before it produced an empty box.

https://claude.ai/code/session_01PTY4KwAeZdAVvgSWxjpYfs

---

Note

Medium Risk
Touches cloud session startup on create/start paths for all three agents; wrong behavior could leave boxes running without agents or fail loudly on credential issues, but scope is limited to --no-attach and reuses an existing helper.

Overview
Cloud --no-attach now starts the agent in a detached tmux session instead of leaving the box empty until attach. Behavior matches Docker: the session is created up front; only the host terminal attach is skipped.

cloudAgentCreate no longer returns early when attach === false; it calls cloudAgentStartDetached (same helper as the -i queue worker) to launch and verify the session.

The claude, codex, and opencode start subcommands on non-docker boxes follow the same pattern: resolve args (skip-perms, resume teleport where applicable), then cloudAgentStartDetached on --no-attach, with updated outro text instead of the old “lazy on attach” message.

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
agentbox-web	Skipped		Jun 26, 2026 10:53am

[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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[cursor]

Detached start skips resume args

Medium Severity

New --no-attach cloud paths call cloudAgentStartDetached with raw extraArgs only. The attach path in cloudAgentAttach still adds agentResumeArgs when args are empty for claude/codex, so background create/start can launch a fresh agent instead of resuming the box’s recorded session (e.g. after checkpoint restore or claude start with no post--- args).

Additional Locations (2)

• apps/cli/src/commands/claude.ts#L1435-L1444
• apps/cli/src/commands/codex.ts#L1069-L1078

 

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