majiayu000 Consult Codex
Multi-turn consultation with Codex CLI. Maintains a conversation across multiple turns using session persistence, unlike single-shot /codex-exec.
Step 1: Gather Context
Identify the 2-5 files most relevant to the problem. Formulate a clear, specific question. Include what has been tried and relevant constraints.
Step 2: Start Session
Run codex exec with -o to capture the response cleanly. Default to -s read-only for safety. Use -s workspace-write when the consultation requires running code or reading files outside the workspace.
All codex Bash calls require dangerouslyDisableSandbox: true (network access to OpenAI API). Use .turbo/ as the temp directory — it is in the working directory (sandbox-writable), gitignored, and avoids $TMPDIR path mismatches between sandbox and non-sandbox mode.
Non-piped codex exec invocations require < /dev/null to avoid hanging on stdin. Codex reads from stdin whenever stdin is non-TTY, and in subprocess contexts the harness leaves stdin connected to a pipe that never EOFs — codex blocks forever, printing only Reading additional input from stdin.... The piped form (cat file | codex exec "...") is safe — cat closes the pipe after the file.
Generate a random session tag at the start to keep files unique for parallel use:
CODEX_TAG=$(head -c 4 /dev/urandom | xxd -p) && mkdir -p .turbo/codex
codex exec -s read-only -o ".turbo/codex/$CODEX_TAG.txt" "<question with full context>" < /dev/null
Prompt Shaping
Structure the question using XML tags for clearer Codex responses:
<task>: The concrete question and relevant context.<compact_output_contract>: Desired output shape and brevity requirements.<structured_output_contract>: Same purpose but for structured/schema responses.<grounding_rules>: When claims must be evidence-based (review, research, root-cause analysis).<dig_deeper_nudge>: Push past surface-level findings to check for second-order failures.<verification_loop>: When correctness matters — ask Codex to verify before finalizing.
Example prompt for a diagnosis question:
<task>Diagnose why the auth middleware rejects valid tokens after the session refactor.</task>
<compact_output_contract>Return: (1) most likely root cause, (2) evidence, (3) smallest safe next step.</compact_output_contract>
<grounding_rules>Ground every claim in the provided context or tool outputs. Label hypotheses explicitly.</grounding_rules>
For correctness-critical questions, add <verification_loop> asking Codex to verify its answer before finalizing.
Keep prompts compact, with tight output contracts. One clear task per Codex turn.
For long context that won't fit inline, write a context file and pipe it via stdin. The prompt stays as the argument, context pipes in as <stdin> automatically:
cat > ".turbo/codex/$CODEX_TAG-ctx.txt" << 'EOF'
<long context here>
EOF
cat ".turbo/codex/$CODEX_TAG-ctx.txt" | codex exec -s read-only -o ".turbo/codex/$CODEX_TAG.txt" "<question>"
Parse the session id: line from the CLI output. This UUID is needed for follow-up turns.
Use a generous timeout (30 minutes / 1800000ms per turn).
Step 3: Read and Evaluate Response
The -o file contains only Codex's response (cleaner than stdout, which includes CLI chrome and tool-use logs). Read from .turbo/codex/$CODEX_TAG.txt. If the output is too large for the Read tool, read stdout from the Bash tool result instead.
Assess whether:
- The answer is sufficient and actionable
- Follow-up questions would improve the answer
- The response contradicts known project facts (verify before accepting)
If no follow-up is needed, skip to the Synthesize step.
Step 4: Follow Up
Resume the session with the parsed session ID (not --last, which is unsafe for parallel use):
codex exec resume <session-id> -o ".turbo/codex/$CODEX_TAG.txt" "<follow-up question>" < /dev/null
The -s flag is not available for resume. It inherits sandbox settings from the original session.
Return to Step 3. Cap at 5 turns to prevent runaway conversations.
Step 5: Synthesize
Summarize the key insights from the consultation. Cross-reference suggestions with project documentation and conventions before applying. Codex suggestions are starting points, not guaranteed solutions.