Codex Oracle

Use OpenAI Codex CLI as a read-only oracle — planning, review, and analysis only. Codex provides its perspective; you synthesize and present results to the user.

Sandbox is always read-only. Codex must never implement changes.

Arguments

Parse $ARGUMENTS for:

• query — the main question or task (everything not a flag). Required — if empty, tell the user to provide a query and stop.
• --reasoning <level> — override reasoning effort (low, medium, high, xhigh). Optional; default is auto-selected based on complexity.

Prerequisites

Run the check script before any Codex invocation:

scripts/check-codex.sh

If it exits non-zero, display the error and stop. Use the wrapper for all codex exec calls:

scripts/run-codex-exec.sh

Configuration

Setting	Default	Override
Model	gpt-5.3-codex	Allowlist only (see references/codex-flags.md)
Reasoning	Auto	--reasoning <level> or user prose
Sandbox	read-only	Not overridable

Reasoning Effort

Complexity	Effort	Timeout	Criteria
Simple	low	300000ms	<3 files, quick question
Moderate	medium	300000ms	3–10 files, focused analysis
Complex	high	600000ms	Multi-module, architectural thinking
Maximum	xhigh	600000ms	Full codebase, critical decisions

For xhigh tasks that may exceed 10 minutes, use run_in_background: true on the Bash tool and set CODEX_OUTPUT so you can read the output later.

See references/codex-flags.md for full flag documentation.

Workflow

1. Parse and Validate

1. Parse $ARGUMENTS for query and --reasoning
2. Run scripts/check-codex.sh — abort on failure
3. Assess complexity to select reasoning effort (unless overridden)

2. Construct Prompt

Build a focused prompt from the user's query and any relevant context (diffs, file contents, prior conversation). Keep it direct — state what you want Codex to analyze and what kind of output you need. Do not implement; request analysis and recommendations only.

3. Execute

Invoke via the wrapper with HEREDOC. Set the Bash tool timeout per the reasoning effort table above.

EFFORT="<effort>" \
CODEX_OUTPUT="/tmp/codex-${RANDOM}${RANDOM}.txt" \
scripts/run-codex-exec.sh <<'EOF'
[constructed prompt]
EOF

For xhigh, consider run_in_background: true on the Bash tool call, then read CODEX_OUTPUT when done.

4. Present Results

Read the output file and present with attribution:

## Codex Analysis

[Codex output — summarize if >200 lines]

---
Model: gpt-5.3-codex | Reasoning: [effort level]

Synthesize key insights and actionable items for the user.