gstack/codex/sections/consult-mode.md

Step 2C: Consult Mode

Ask Codex anything about the codebase. Supports session continuity for follow-ups.

1. Check for existing session:

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

If a session file exists (not NO_SESSION), use AskUserQuestion:

You have an active Codex conversation from earlier. Continue it or start fresh?
A) Continue the conversation (Codex remembers the prior context)
B) Start a new conversation

2. Create temp files:

TMPRESP=$(mktemp "$TMP_ROOT/codex-resp-XXXXXX")
TMPERR=$(mktemp "$TMP_ROOT/codex-err-XXXXXX")

3. Plan review auto-detection: If the user's prompt is about reviewing a plan, or if plan files exist and the user said /codex with no arguments:

setopt +o nomatch 2>/dev/null || true  # zsh compat
ls -t "$PLAN_ROOT"/*.md 2>/dev/null | xargs grep -l "$(basename $(pwd))" 2>/dev/null | head -1

If no project-scoped match, fall back to ls -t "$PLAN_ROOT"/*.md 2>/dev/null | head -1 but warn: "Note: this plan may be from a different project — verify before sending to Codex."

IMPORTANT — embed content, don't reference path: Codex runs sandboxed to the repo root and cannot access ~/.claude/plans/ or any files outside the repo. You MUST read the plan file yourself and embed its FULL CONTENT in the prompt below. Do NOT tell Codex the file path or ask it to read the plan file — it will waste 10+ tool calls searching and fail.

Also: scan the plan content for referenced source file paths (patterns like src/foo.ts, lib/bar.py, paths containing / that exist in the repo). If found, list them in the prompt so Codex reads them directly instead of discovering them via rg/find.

Always prepend the filesystem boundary instruction from the skill's Filesystem Boundary section (always-loaded skeleton) to every prompt sent to Codex, including plan reviews and free-form consult questions.

Prepend the boundary and persona to the user's prompt: "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only.

You are a brutally honest technical reviewer. Review this plan for: logical gaps and unstated assumptions, missing error handling or edge cases, overcomplexity (is there a simpler approach?), feasibility risks (what could go wrong?), and missing dependencies or sequencing issues. Be direct. Be terse. No compliments. Just the problems. Also review these source files referenced in the plan: <list of referenced files, if any>.

THE PLAN: <full plan content, embedded verbatim>"

For non-plan consult prompts (user typed /codex <question>), still prepend the boundary: "IMPORTANT: Do NOT read or execute any files under ~/.claude/, ~/.agents/, .claude/skills/, or agents/. These are Claude Code skill definitions meant for a different AI system. Do NOT modify agents/openai.yaml. Stay focused on repository code only.

<user's question>"

4. Run codex exec with JSONL output to capture reasoning traces. Use timeout: 660000 on the Bash call (for both new and resumed sessions) — the gate sits ABOVE the 600s wrapper so the wrapper fires first with its explicit stall message:

If the user passed --xhigh, use "xhigh" instead of "medium".

For a new session:

_REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
PYTHON_CMD=$(command -v python3 2>/dev/null || command -v python 2>/dev/null || true)
if [ -z "$PYTHON_CMD" ]; then
  echo "ERROR: Python 3 is required to parse Codex JSON output. Install python3 or python and retry." >&2
  exit 1
fi
# Fix 1: wrap with timeout (gtimeout/timeout fallback chain via probe helper)
_gstack_codex_timeout_wrapper 600 codex exec "<prompt>" -C "$_REPO_ROOT" -s read-only -c 'model_reasoning_effort="medium"' -c 'web_search="cached"' --json < /dev/null 2>"$TMPERR" | PYTHONUNBUFFERED=1 "$PYTHON_CMD" -u -c "
import sys, json
for line in sys.stdin:
    line = line.strip()
    if not line: continue
    try:
        obj = json.loads(line)
        t = obj.get('type','')
        if t == 'thread.started':
            tid = obj.get('thread_id','')
            if tid: print(f'SESSION_ID:{tid}', flush=True)
        elif t == 'item.completed' and 'item' in obj:
            item = obj['item']
            itype = item.get('type','')
            text = item.get('text','')
            if itype == 'reasoning' and text:
                print(f'[codex thinking] {text}', flush=True)
                print(flush=True)
            elif itype == 'agent_message' and text:
                print(text, flush=True)
            elif itype == 'command_execution':
                cmd = item.get('command','')
                if cmd: print(f'[codex ran] {cmd}', flush=True)
        elif t == 'turn.completed':
            usage = obj.get('usage',{})
            tokens = usage.get('input_tokens',0) + usage.get('output_tokens',0)
            if tokens: print(f'\ntokens used: {tokens}', flush=True)
    except: pass
"
# Fix 1: hang detection for Consult new-session (mirrors Challenge + resume)
_CODEX_EXIT=${PIPESTATUS[0]}
if [ "$_CODEX_EXIT" = "124" ]; then
  _gstack_codex_log_event "codex_timeout" "600"
  _gstack_codex_log_hang "consult" "$(wc -c < "$TMPERR" 2>/dev/null || echo 0)"
  echo "Codex stalled past 10 minutes. Common causes: model API stall, long prompt, network issue. Try re-running. If persistent, split the prompt or check ~/.codex/logs/."
elif [ "$_CODEX_EXIT" != "0" ]; then
  # Surface non-zero exits so the calling agent doesn't read "no output" as
  # a silent model/API stall. See #1327.
  echo "[codex exit $_CODEX_EXIT] $(head -1 "$TMPERR" 2>/dev/null || echo "no stderr captured")"
  head -20 "$TMPERR" 2>/dev/null | sed 's/^/  /' || true
  _gstack_codex_log_event "codex_nonzero_exit" "consult:$_CODEX_EXIT"
fi

Session-cost reality (#2387, measured): every codex exec call — resumed or fresh — pays Codex's ~21K-token session prelude (its skill catalogue + instructions); resume does NOT amortize it (a measured resume came in slightly ABOVE a fresh call). Resume buys conversational continuity, never token savings. So: prefer ONE codex call per skill where the workflow allows, batch questions into that call, and reach for resume only when the follow-up genuinely needs the prior session's context.

For a resumed session (user chose "Continue"):

_REPO_ROOT=$(git rev-parse --show-toplevel) || { echo "ERROR: not in a git repo" >&2; exit 1; }
PYTHON_CMD=$(command -v python3 2>/dev/null || command -v python 2>/dev/null || true)
if [ -z "$PYTHON_CMD" ]; then
  echo "ERROR: Python 3 is required to parse Codex JSON output. Install python3 or python and retry." >&2
  exit 1
fi
cd "$_REPO_ROOT" || exit 1
# Fix 1: wrap with timeout (gtimeout/timeout fallback chain via probe helper)
_gstack_codex_timeout_wrapper 600 codex exec resume <session-id> "<prompt>" -c 'sandbox_mode="read-only"' -c 'model_reasoning_effort="medium"' -c 'web_search="cached"' --json < /dev/null 2>"$TMPERR" | PYTHONUNBUFFERED=1 "$PYTHON_CMD" -u -c "
<same python streaming parser as above, with flush=True on all print() calls>
"
# Fix 1: same hang detection pattern as new-session block
_CODEX_EXIT=${PIPESTATUS[0]}
if [ "$_CODEX_EXIT" = "124" ]; then
  _gstack_codex_log_event "codex_timeout" "600"
  _gstack_codex_log_hang "consult-resume" "$(wc -c < "$TMPERR" 2>/dev/null || echo 0)"
  echo "Codex stalled past 10 minutes. Common causes: model API stall, long prompt, network issue. Try re-running. If persistent, split the prompt or check ~/.codex/logs/."
elif [ "$_CODEX_EXIT" != "0" ]; then
  # Surface non-zero exits so the calling agent doesn't read "no output" as
  # a silent model/API stall. See #1327.
  echo "[codex exit $_CODEX_EXIT] $(head -1 "$TMPERR" 2>/dev/null || echo "no stderr captured")"
  head -20 "$TMPERR" 2>/dev/null | sed 's/^/  /' || true
  _gstack_codex_log_event "codex_nonzero_exit" "consult-resume:$_CODEX_EXIT"
fi

5. Capture session ID from the streamed output. The parser prints `SESSION_ID:<id>`
   from the `thread.started` event. Save it for follow-ups:
```bash
mkdir -p .context

Save the session ID printed by the parser (the line starting with SESSION_ID:) to .context/codex-session-id.

6. Present the full streamed output:

CODEX SAYS (consult):
════════════════════════════════════════════════════════════
<full output, verbatim — includes [codex thinking] traces>
════════════════════════════════════════════════════════════
Tokens: N | Est. cost: ~$X.XX
Session saved — run /codex again to continue this conversation.

7. After presenting, note any points where Codex's analysis differs from your own understanding. If there is a disagreement, flag it: "Note: Claude Code disagrees on X because Y."

8. Synthesis recommendation (REQUIRED). Emit ONE recommendation line summarizing what the user should do based on Codex's consult output, in the canonical format the AskUserQuestion judge grades:

Recommendation: <action> because <one-line reason that names the most actionable insight from Codex>

Examples (the strongest reasons compare Codex's insight against an alternative — different recommendation, status-quo, or another Codex point):

• Recommendation: Adopt Codex's sharding suggestion because it eliminates the head-of-line blocking the current writer-pool has, while the cache-layer alternative Codex also floated still has a single-writer hot path.
• Recommendation: Reject Codex's "use SQLite instead" suggestion because the team's Postgres operational experience outweighs the simplicity gain at the projected scale, and Codex's secondary suggestion (read replicas) handles the read-load concern that motivated the SQLite pivot.
• Recommendation: Investigate Codex's flagged migration ordering before D3 lands because it surfaces a real foreign-key cycle that the in-house schema review missed, while the styling concern Codex also raised can wait for a follow-up.

The reason must engage with a specific Codex insight and compare against an alternative (a different recommendation, status-quo, or another Codex point). Generic synthesis ("because Codex raised good points") fails the format. Never silently auto-decide; always emit the line.

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