gstack/skills/review/references/legacy/claude.md

Step 0: Detect platform and base branch

First, detect the git hosting platform from the remote URL:

git remote get-url origin 2>/dev/null

• If the URL contains "github.com" → platform is GitHub
• If the URL contains "gitlab" → platform is GitLab
• Otherwise, check CLI availability:
  • gh auth status 2>/dev/null succeeds → platform is GitHub (covers GitHub Enterprise)
  • glab auth status 2>/dev/null succeeds → platform is GitLab (covers self-hosted)
  • Neither → unknown (use git-native commands only)

Determine which branch this PR/MR targets, or the repo's default branch if no PR/MR exists. Use the result as "the base branch" in all subsequent steps.

If GitHub:

1. gh pr view --json baseRefName -q .baseRefName — if succeeds, use it
2. gh repo view --json defaultBranchRef -q .defaultBranchRef.name — if succeeds, use it

If GitLab:

1. glab mr view -F json 2>/dev/null and extract the target_branch field — if succeeds, use it
2. glab repo view -F json 2>/dev/null and extract the default_branch field — if succeeds, use it

Git-native fallback (if unknown platform, or CLI commands fail):

1. git symbolic-ref refs/remotes/origin/HEAD 2>/dev/null | sed 's|refs/remotes/origin/||'
2. If that fails: git rev-parse --verify origin/main 2>/dev/null → use main
3. If that fails: git rev-parse --verify origin/master 2>/dev/null → use master

If all fail, fall back to main.

Print the detected base branch name. In every subsequent git diff, git log, git fetch, git merge, and PR/MR creation command, substitute the detected branch name wherever the instructions say "the base branch" or <default>.

---

$review --mode Deep --module claude - Claude Outside Voice

You are running the $review --mode Deep --module claude skill from a non-Claude host. This wraps claude -p to get an independent Claude Code second opinion without allowing nested Claude to modify files.

The generated external invocation name is gstack-claude.

---

Step 0: Check Claude CLI

CLAUDE_BIN=$(command -v claude 2>/dev/null || echo "")
[ -z "$CLAUDE_BIN" ] && echo "NOT_FOUND" || echo "FOUND: $CLAUDE_BIN"

If NOT_FOUND, stop and tell the user: "Claude CLI not found. Install Claude Code, then re-run this skill."

Check auth:

if [ -f "$HOME/.claude/.credentials.json" ] || [ -n "${ANTHROPIC_API_KEY:-}" ]; then
  echo "AUTH_FOUND"
else
  echo "AUTH_MISSING"
fi

If AUTH_MISSING, stop and tell the user: "No Claude authentication found. Run claude interactively to log in, or export ANTHROPIC_API_KEY, then re-run this skill."

---

Safety Boundary

Nested Claude must stay focused on the user's repository and must not run gstack skills from inside this skill.

All claude -p calls MUST include:

• --disable-slash-commands
• Review/challenge: --tools ""
• Consult: --allowedTools Read,Grep,Glob --disallowedTools Bash,Edit,Write

Never pass Bash, Edit, or Write to nested Claude in this skill.

All prompts MUST be written to a temp file and fed through stdin. Never interpolate user text directly into the shell command.

---

Step 1: Detect Mode

Parse the user's input:

1. $review --mode Deep --module claude review or $review --mode Deep --module claude review <instructions> - Review mode (Step 2A)
2. $review --mode Deep --module claude challenge or $review --mode Deep --module claude challenge <focus> - Challenge mode (Step 2B)
3. $review --mode Deep --module claude with no arguments, or $review --mode Deep --module claude <anything else> - Consult mode (Step 2C)

If no mode is obvious and a diff exists, ask whether to review, challenge, or consult.

---

Shared Helpers

Use these shell snippets in every mode.

Create temp files:

PROMPT_FILE=$(mktemp /tmp/gstack-claude-prompt-XXXXXX)
RESP_FILE=$(mktemp /tmp/gstack-claude-response-XXXXXX.json)
ERR_FILE=$(mktemp /tmp/gstack-claude-error-XXXXXX.txt)

Cleanup at the end of every mode:

rm -f "$PROMPT_FILE" "$RESP_FILE" "$ERR_FILE"

Parse JSON output:

python3 - "$RESP_FILE" <<'PY'
import json, sys
path = sys.argv[1]
try:
    obj = json.load(open(path))
except Exception as exc:
    print(f"CLAUDE_JSON_PARSE_ERROR: {exc}")
    sys.exit(0)

if obj.get("is_error"):
    print("CLAUDE_ERROR: true")

result = obj.get("result") or obj.get("response") or ""
if result:
    print(result)

usage = obj.get("usage") or {}
input_tokens = usage.get("input_tokens", 0) or 0
output_tokens = usage.get("output_tokens", 0) or 0
cache_read = usage.get("cache_read_input_tokens", 0) or 0
model = obj.get("model") or "unknown"
session_id = obj.get("session_id") or ""

print(f"\nTokens: input={input_tokens} output={output_tokens} cache_read={cache_read} | Model: {model}")
if session_id:
    print(f"SESSION_ID:{session_id}")
PY

If stderr contains auth, login, or unauthorized, tell the user: "Claude authentication failed. Run claude interactively to authenticate or export ANTHROPIC_API_KEY."

---

Step 2A: Review Mode

Review the current branch diff with nested Claude in tool-less mode.

1. Fetch base and capture diff:

_REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
cd "$_REPO_ROOT"
DIFF_FILE=$(mktemp /tmp/gstack-claude-diff-XXXXXX.patch)
git fetch origin <base> --quiet 2>/dev/null || true
git diff "origin/<base>" > "$DIFF_FILE" 2>/dev/null || git diff "<base>" > "$DIFF_FILE"

If the diff file is empty, stop and say: "Nothing to review - no changes against the base branch."

2. Write the prompt file:

cat > "$PROMPT_FILE" <<'EOF'
You are a brutally honest Claude Code reviewer. Review this git diff for bugs,
production failure modes, security issues, missing tests, and maintainability
problems. Be direct. No compliments. Reference files and changed code where possible.

Additional user instructions, if any:
<custom review instructions>

DIFF:
EOF
cat "$DIFF_FILE" >> "$PROMPT_FILE"

3. Run Claude:

cat "$PROMPT_FILE" | claude -p --output-format json --disable-slash-commands --tools "" > "$RESP_FILE" 2>"$ERR_FILE"

4. Present the parsed output:

CLAUDE SAYS (code review):
============================================================
<parsed result from RESP_FILE>
============================================================

5. Cleanup:

rm -f "$DIFF_FILE" "$PROMPT_FILE" "$RESP_FILE" "$ERR_FILE"

---

Step 2B: Challenge Mode

Run an adversarial failure-mode review with nested Claude in tool-less mode.

1. Capture the diff using the same diff commands from Review mode.

2. Write the prompt:

cat > "$PROMPT_FILE" <<'EOF'
You are an adversarial Claude Code reviewer. Try to break this change before users do.
Find edge cases, race conditions, security holes, resource leaks, silent data
corruption, bad error handling, and operational failure modes. Be thorough. No
compliments. If the user provided a focus area, prioritize it.

Focus area, if any:
<focus>

DIFF:
EOF
cat "$DIFF_FILE" >> "$PROMPT_FILE"

3. Run Claude:

cat "$PROMPT_FILE" | claude -p --output-format json --disable-slash-commands --tools "" > "$RESP_FILE" 2>"$ERR_FILE"

4. Present the parsed output:

CLAUDE SAYS (adversarial challenge):
============================================================
<parsed result from RESP_FILE>
============================================================

5. Cleanup:

rm -f "$DIFF_FILE" "$PROMPT_FILE" "$RESP_FILE" "$ERR_FILE"

---

Step 2C: Consult Mode

Ask Claude about the repository. Consult mode may inspect files, but only with read-only tools.

1. Check for an existing Claude session:

cat .context/claude-session-id 2>/dev/null || echo "NO_SESSION"

If a session exists, ask the user whether to continue it or start fresh.

2. Write the prompt:

cat > "$PROMPT_FILE" <<'EOF'
You are Claude Code acting as an independent outside voice for this repository.
Answer the user's question directly. You may inspect repository files with Read,
Grep, and Glob only. Do not use Bash. Do not edit or write files. Do not invoke
slash commands or gstack skills.

USER QUESTION:
<user prompt>
EOF

3. Run Claude.

For a new session:

cat "$PROMPT_FILE" | claude -p --output-format json --disable-slash-commands --allowedTools Read,Grep,Glob --disallowedTools Bash,Edit,Write > "$RESP_FILE" 2>"$ERR_FILE"

For a resumed session:

cat "$PROMPT_FILE" | claude -p --resume "<session-id>" --output-format json --disable-slash-commands --allowedTools Read,Grep,Glob --disallowedTools Bash,Edit,Write > "$RESP_FILE" 2>"$ERR_FILE"

4. Parse and save the session id:

SESSION_ID=$(python3 - "$RESP_FILE" <<'PY'
import json, sys
try:
    obj = json.load(open(sys.argv[1]))
    print(obj.get("session_id") or "")
except Exception:
    print("")
PY
)
if [ -n "$SESSION_ID" ]; then
  mkdir -p .context
  printf "%s\n" "$SESSION_ID" > .context/claude-session-id
fi

5. Present the parsed output:

CLAUDE SAYS (consult):
============================================================
<parsed result from RESP_FILE>
============================================================
Session saved - run $review --mode Deep --module claude again to continue this conversation.

6. Cleanup:

rm -f "$PROMPT_FILE" "$RESP_FILE" "$ERR_FILE"

---

Error Handling

• Binary not found: Stop with install instructions.
• Auth missing: Stop with login/API key instructions.
• Auth failure from stderr: Surface the stderr line and ask the user to re-authenticate.
• JSON parse failure: Show raw stdout from $RESP_FILE and stderr from $ERR_FILE.
• Empty response: Tell the user "Claude returned no response. Check stderr for errors."
• Resume failure: Delete .context/claude-session-id and retry with a fresh session.

---

Important Rules

• Nested Claude is read-only in consult mode and tool-less in review/challenge.
• Always include --disable-slash-commands.
• Never pass nested Claude Bash, Edit, or Write.
• Never interpolate user text into a shell command.
• Present Claude's response faithfully, then add any host-agent synthesis after it.

Upstream judgment port: PR #679

Match the user language

User-language rule

Write questions, progress updates, reports, and artifacts in the language used by the user. Source material, code identifiers, commands, and quotations may remain in their original language when translating them would reduce accuracy.