[saddlepaddle]

What

Agent and preset launches could end up typed at the prompt but never executed: the workspace was created, the agent terminal opened, and the full launch command ('claude' '--dangerously-skip-permissions' '<prompt>') sat in the shell's edit buffer with the cursor blinking after it. Reported as "the new workspace page creates a workspace but doesn't start the agent" — but it's page-agnostic and hits every initialCommand consumer (modal creates, automations, setup terminals).

Root cause

The OSC 133;A shell-ready marker is emitted from a precmd hook, which runs before the prompt is drawn and before the line editor starts reading input. Writing command\n in that gap lets shell plugin init (oh-my-zsh vi-mode, syntax-highlighting — worst under first-create load) flush the PTY input queue mid-read: the command text survives into the editor's buffer, the trailing newline is lost.

Confirmed live via CDP against the dev app: on the first workspace create after boot the command was stuck unexecuted; sending one synthetic Enter keypress launched Claude immediately, which then completed the prompt's task — proving only the newline was missing. This is the residual hole in the #4963 → #5774 (first-prompt gate) → #5927 (15s bound) series.

Fix

In queueInitialCommand:

• strip trailing newlines from the command text and write it alone;
• 500ms later, send Enter as its own write — and as \r (what a real Enter key sends, bound to accept-line in every keymap) instead of \n (relies on the ^J binding).

Exactly one Enter is ever sent, so double-execution is impossible. If startup eats the text itself, the stray \r is a no-op at an empty prompt — every failure mode is strictly no-worse than before. Same technique VS Code shell integration uses; v1 avoided the class entirely by launching via shell -lc, which is why v1 never hit this.

Verification

• bun run test:e2e (host-service): 20/20 pass, including the direnv input-consumption simulation and the promptness bound (command executed in 517ms with the new delay).
• End-to-end via CDP on the dev desktop app: pre-fix, first create after boot reproduced the stuck command (screenshot evidence, before/after Enter). Post-fix, restarted the app and ran the full /new-workspace flow twice with real input events — both creates launched Claude, which replied within ~2s. Setup terminals unaffected.
• Biome + tsc clean.

https://claude.ai/code/session_01CwWxQTQW2zLeN9hhRkQNxT

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---

Summary by cubic

Fixes an intermittent issue where the initial launch command was typed but not executed. We now send the command text and Enter separately with a short delay for reliable execution.

• Bug Fixes
  • In packages/host-service/src/terminal/terminal.ts, strip trailing CR/LF from initialCommand and write only the text.
  • Send Enter as a separate \r 500 ms after shell-ready to avoid plugin init eating it.
  • Update packages/host-service/test/integration/setup-scripts.integration.test.ts to assert split write and delayed \r; tidy assertion formatting.
  • Applies to all initialCommand flows (new workspace, modal creates, automations, setup terminals).

^{Written for commit 56af206. Summary will update on new commits.}

Summary by CodeRabbit

• Bug Fixes
  • Improved reliability of terminal “initial command” execution by sending the command text and the Enter keystroke as two separate, ordered writes.
  • Normalized the command text to remove any trailing CR/LF characters before sending, and added a brief delay for better alignment with shell readiness.
• Tests
  • Updated the integration test to assert the command is written without \n, and that the Enter (\r) write occurs afterward.

[ghost]

Ready to review this PR? Stage has broken it down into 3 individual chapters for you:

	Title
1	Define delay for initial command execution
2	Split initial command text and Enter keypress
3	Update integration tests for split command writes

_{Chapters generated by Stage for commit 56af206 on Jul 28, 2026 10:22pm UTC.}

[coderabbitai]

📝 Walkthrough

Walkthrough

Initial terminal commands are trimmed, written after shell readiness, and followed by a delayed carriage return. Integration coverage verifies the separate write order.

Changes

Initial command dispatch

Layer / File(s)	Summary
Command write timing and validation packages/host-service/src/terminal/terminal.ts, packages/host-service/test/integration/setup-scripts.integration.test.ts	Adds a fixed Enter delay, trims trailing CR/LF characters from initial commands, writes command text after shell readiness, sends \r in a delayed second write, and verifies the write order.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• superset-sh/superset#4963: Modifies the same terminal initial-command dispatch and timing logic.
• superset-sh/superset#5774: Changes shell-readiness gating in the same command-send flow.
• superset-sh/superset#5927: Changes shell-readiness resolution for preset command dispatch.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title is concise, conventional, and accurately summarizes the main change.
Description check	✅ Passed	The description covers the problem, root cause, fix, and verification, though the checklist section is not fully filled out.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/host-service-initial-command-enter

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[github-actions]

🧹 Preview Cleanup Complete

The following preview resources have been cleaned up:

• ✅ Neon database branch

Thank you for your contribution! 🎉

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@packages/host-service/test/integration/setup-scripts.integration.test.ts`:
- Around line 126-133: Update the waitFor predicate in the integration test to
count carriage-return writes and require exactly one "\r", with that sole Enter
occurring after the setup command write. Keep the existing diagnostic message
and command-order assertion intact.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: ad3f95d4-7281-4e43-ad99-c9f8fe54932a

📥 Commits

Reviewing files that changed from the base of the PR and between 53c7850 and 9d8a24b.

📒 Files selected for processing (1)

• packages/host-service/test/integration/setup-scripts.integration.test.ts

[coderabbitai]

🎯 Functional Correctness | 🟡 Minor | ⚡ Quick win

Assert that exactly one Enter is written.

This predicate passes if two "\r" writes occur after the command. Count the carriage-return writes and assert that the sole one follows the command, matching the PR’s exactly-one-Enter contract.

Proposed assertion

-			() =>
-				writes.includes("echo setup-a && echo setup-b") &&
-				writes.indexOf("\r") > writes.indexOf("echo setup-a && echo setup-b"),
+			() => {
+				const commandIndex = writes.indexOf("echo setup-a && echo setup-b");
+				return (
+					commandIndex !== -1 &&
+					writes.filter((write) => write === "\r").length === 1 &&
+					writes.indexOf("\r") > commandIndex
+				);
+			},

📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change

	// The command text and its Enter arrive as separate writes (the Enter is
	// delayed so shell startup can't eat it) — assert both, in order.
	await waitFor(
	() => writes.includes("echo setup-a && echo setup-b\n"),
	() =>
	writes.includes("echo setup-a && echo setup-b") &&
	writes.indexOf("\r") > writes.indexOf("echo setup-a && echo setup-b"),
	5000,
	() => `expected setup command write, got ${JSON.stringify(writes)}`,
	() => `expected setup command write + Enter, got ${JSON.stringify(writes)}`,
	// The command text and its Enter arrive as separate writes (the Enter is
	// delayed so shell startup can't eat it) — assert both, in order.
	await waitFor(
	() => {
	const commandIndex = writes.indexOf("echo setup-a && echo setup-b");
	return (
	commandIndex !== -1 &&
	writes.filter((write) => write === "\r").length === 1 &&
	writes.indexOf("\r") > commandIndex
	);
	},
	5000,
	() => `expected setup command write + Enter, got ${JSON.stringify(writes)}`,

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@packages/host-service/test/integration/setup-scripts.integration.test.ts`
around lines 126 - 133, Update the waitFor predicate in the integration test to
count carriage-return writes and require exactly one "\r", with that sole Enter
occurring after the setup command write. Keep the existing diagnostic message
and command-order assertion intact.