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
— 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
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
Parse
$ARGUMENTS
for query and
--reasoning
Run
scripts/check-codex.sh
— abort on failure
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
=
""
\
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.