fix(chat): show a Claude slash command's answer and suggest /goal

[devswha]

What

Two fixes for Claude Code panes in Chat, both reported by @knightnemo in #578:

• A slash command's answer shows in the chat. Claude Code records what a slash command printed as {type: "system", subtype: "local_command", content: "<local-command-stdout>…</local-command-stdout>"} (or -stderr). parseClaudeTranscript now turns that output into a notice part, so a refused /goal ("/goal can't run while hooks are restricted …") is readable in Chat instead of only in the terminal.
• /goal is suggested. It joins the Claude built-ins with its argument hint, [condition|clear].

Why

The parser read only message.content, and these records keep their text in a top-level content, so they parsed to nothing: a user who set a goal from Chat could not tell whether Claude Code accepted it. /goal was missing from the hard-coded built-in list.

How

• server/conversation.ts: a local_command system entry with stdout or stderr becomes a turn in the user's seat with { kind: "notice", text, source: "local-command" }. This is the part pi-family runtime messages already use, and ChatView labels a notice with a named source by its first line, so there is no new wire field, UI string or demo answer. Terminal colour codes are stripped. The command's echo record (<command-name>…) and an empty answer stay out, as slash-command bookkeeping always has; the older user-message filtering is unchanged. Like a pi notice, the record does not open a page.
• server/commands.ts: goal in the Claude list, described the way pi's commands carry an argument hint.

No agent hooks or settings are read or written.

How verified

• Both bugs reproduced first as failing unit tests on main (59 pass, 2 fail), then green with the fix (61 pass, 0 fail in server/commands.test.ts and server/conversation.test.ts).
• Mutations turn the new tests red: removing goal from the built-ins, disabling the local_command branch, and dropping the colour-code strip each fail exactly one test.
• The issue's own repro scripts, run against this branch: paneCommands('claude', null, home) includes goal, and the two-record fixture parses to one notice carrying the refusal, also when read from a file through transcriptPage("claude-transcript", …).
• bun run check fast: workflow syntax, generated types, typecheck, build and unit tests (1717 pass, 0 fail) all ok.

Not verified live: a real Claude Code session's /goal through the browser. The record shape is the one the issue captured from Claude Code 2.1.251.

Part of #578. The goal-status card for the bare /goal dialog asked for there is a new feature and stays open.

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📒 Files selected for processing (3)

• CHANGELOG.md
• server/conversation.test.ts
• server/conversation.ts

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📝 Summary

Summary by CodeRabbit

• New Features
  • Claude Code now displays responses from slash commands, including refusals, in chat.
  • /goal is available among message-box suggestions and Claude Code’s built-in commands.
• Bug Fixes
  • Slash-command output is now shown in chat, while empty command responses are omitted.

Walkthrough

Claude now offers /goal in its built-in command list. Transcript parsing converts nonempty output from Claude local-command records into notice turns, and tests cover command listing and transcript handling.

Changes

Claude slash-command chat support

Layer / File(s)	Summary
Expose the goal command server/commands.ts, server/commands.test.ts	Claude's built-in commands include goal with a [condition|clear] description. Tests check that Codex does not offer goal.
Render local command output server/conversation.ts, server/conversation.test.ts, CHANGELOG.md	Transcript parsing extracts and trims stdout and stderr from local-command system records, removes ANSI color codes, and creates a user notice for nonempty output. Tests cover omitted command echoes and empty output. The changelog documents slash-command responses and the /goal suggestion.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~15 minutes

Change: Bug fix

Suggested reviewers: diegolhambi, kilhyeonjun

Merge Risk: 🟡 Moderate · up to de550

A slash command with large output can send an oversized chat response to the browser. Limit notice output before merging unless that risk is explicitly accepted.

Security Architecture Review

Security architecture risk: 🔵 Low · up to de550

Command answers use the existing notice display without granting additional execution permissions. No security vulnerability was established. Large answers can increase response and browser resource use, although transcript paging limits their size; the external runtime’s output limits remain unverified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• observed — The new content is exposed through the conversation selected for a recognized pane. Claude transcript resolution uses a validated session identifier and the pane process’s configuration directory; request-supplied notice text is not accepted by this read route.

Trust Boundaries and Controls

• observed — Runtime output remains display data: the notice renderer precedes ordinary user-message rendering and uses text children rather than interpreting notice content as HTML. ANSI stripping is a presentation transformation, not an authorization control.
• observed — The conversation and command routes remain behind the existing access gate. Mutating API requests additionally require same-origin checks, and watch-role devices are denied mutations, including pane input.

Resilience and Maintainability Implications

• inferred — There is no per-notice or JSON-response size cap, so newly displayed output can increase server serialization and browser allocation. Nevertheless, newest-page reads are indirectly bounded by the 16 MiB start-selection window, and older-page widening stops at 64 MiB. These controls counter an unbounded-output claim; lower-trust control of the external producer was not established.

Hardening Proposals

• proposed — A bounded notice preview with explicit truncation could reduce response and browser allocation for large runtime answers. This is optional containment hardening, not a verified attack path.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 4 files. (1 skipped: 1…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes both main changes: displaying Claude slash-command responses and suggesting /goal.
Description check	✅ Passed	The description explains the problem, resulting behavior, implementation, scope, and validation results. It uses headings different from the template, but it provides the required Change and Validatio…
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.

Full details: Docstring Coverage

Explanation

Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 4 functions across 4 files. (1 skipped: 1 unsupported.)

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Actionable comments posted: 1

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🤖 Prompt to fix review comments

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Inline comments:
Review comments at @server/conversation.ts:
- Around line 83-85: Limit the combined stdout and stderr text returned by the
local-command output helper before it is used to create a notice. Reuse the
output-size limit and truncation behavior already applied to tool results in the
parser, keeping the existing escape-code removal and empty-output filtering.

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ℹ️ Review info

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📒 Files selected for processing (5)

• CHANGELOG.md
• server/commands.test.ts
• server/commands.ts
• server/conversation.test.ts
• server/conversation.ts

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[devswha]

Independent review of f0c5454 (the follow-up commit written while reviewing this PR), at head aa667cb. Verdict: OK to merge. The findings below are non-blocking.

What I checked

• Echo vs. answer. A notice is now shown only when the whole local_command entry is one <local-command-stdout> or <local-command-stderr> block, so an echo whose <command-args> quotes the tag stays an echo. I checked every Claude Code transcript on one PC (2128 files): all 25 output records are exactly one whole stdout block, and none of the 23 echo records carries an output tag. The rule fits every real shape seen there.
• Escape stripping. I probed it with scratch inputs:
  • SGR colours, 24-bit colour, CSI erase and backspace are removed.
  • OSC 8 links terminated by BEL or ST keep their text and lose their address; an OSC 0 title is removed.
  • Ordinary text is untouched: tabs, newlines, <, >, &, <b>.
• Cap. 10 000 characters become 4000 plus …, and exactly 4000 stay as they are. The … marks the cut, and the constant says the rest stays in the terminal.
• The test fails without the fix. With 04e63c3's server/conversation.ts, the new case fails (49 pass, 1 fail); with f0c5454, conversation.test.ts passes 50/50.

Non-blocking findings (none is worse than before this commit)

1. Low: an OSC that is never terminated (ESC]8;;https://…?t=x open with no BEL/ST) is not matched by the OSC rule. Then \u001b. removes only ESC], so 8;;https://…?t=x open shows, address included. That is malformed output, and before this commit no OSC was stripped at all. Ending the OSC match at end of input as well ((?:\u0007|\u001b\\|$)) would close it.
2. Low: a three-byte escape such as ESC(B, which tput sgr0 prints, leaves its last byte: ESC(Bplain shows as Bplain. \u001b[ -/]*[0-~] instead of \u001b. covers these nF sequences.
3. Low, unverified shape: one entry that holds both a stdout and a stderr block now shows nothing, where before it showed both. Two stdout blocks in one entry show the inner tags as text (a</local-command-stdout>\n<local-command-stdout>b). No real transcript I could find has either shape.
4. Nit: 8-bit C1 controls are not removed (\u009b31mred shows 31mred), and a lone \r joins progress lines (50%\r100% shows 50%100%).
5. Nit: the cut can split a surrogate pair, so an emoji at character 4000 leaves a lone high surrogate before the ….
6. Nit: LOCAL_COMMAND_MAX_CHARS and its doc comment now sit between localCommandOutput's JSDoc and the function, so that JSDoc documents the constant. Its sentence "the command's echo … is a separate entry with no output tag" is also no longer the whole story.

Not run

bun run check fast / CI for this head; this review covers the commit's logic and its unit test only. I pushed nothing to the branch.

[devswha]

Independent review (merge-own lane).

Classification: chat bug fix, part of #578 (it must not close it, and does not: the body and commits say "Part of #578"). A refused /goal said why only in the terminal, and /goal was missing from the Claude suggestions.

What I checked:

• No wire change. The notice part already exists (shared/protocol.ts:287, { kind: "notice"; text: string; source?: string }), and ChatView labels a sourced notice by its first line, so neither shared/protocol.ts nor site/demo/transport.ts changes.
• Existing chats render the same, except that system/local_command records with output now show. Codex compared ordinary transcripts with the base parser 450 times, warm and cold cache, and found no difference. Old transcripts re-read after the change will now show the answers of past slash commands; that is the change itself.
• The tests can fail: with the local_command branch disabled, the new test fails.

Codex (gpt-6.1-sol, xhigh, adversarial) raised three Medium findings. I verified all three and fixed them on this branch (f0c5454), with a test that fails on the PR's parser and passes with the fix:

1. The command echo uses the same system/local_command record (the PR's own fixture shows it), and the unanchored regex took a <local-command-stdout> quoted inside <command-args> as an answer. Now only an entry that is wholly one stdout/stderr block counts.
2. Only numeric SGR colour codes were stripped. An OSC 8 link's hidden address (which can carry a token), cursor moves and backspaces reached the chat as text. Now every escape sequence is removed (a link keeps its visible text) along with other control characters, except newline and tab.
3. There was no size cap: an 8 MiB answer went out whole in every conversation page. A notice now stops at 4,000 characters; the rest stays in the terminal.

What I ran (separate worktree): server/conversation.test.ts and server/commands.test.ts, 62 pass. bun run check fast with the fix: 1720 pass, 0 fail. Updated with main (after #582) as aa667cb; Fast checks and Integration and browser are green on aa667cb. The one CodeRabbit thread (size limit) was already covered by f0c5454; replied and resolved.

Since f0c5454 is my own commit, rev-582 reviewed it independently and found it OK to merge (#583 (review)). Its non-blocking Lows are follow-ups, not fixed here: an unterminated OSC sequence keeps its address; ESC(B (charset select) leaves a stray B; an entry holding both a stdout and a stderr block shows nothing.