Diverge Codex

Diverge → Codex

Delegate a task to Codex (GPT-5.4) with explicit creative divergence instructions. Claude structures the prompt; Codex brainstorms; Claude presents the options for selection; Codex implements the chosen approach. Running the brainstorm on a second model family widens the space of approaches beyond what one model proposes.

Heritage and scope

Cross-model sibling of diverge, grounded in Creative Preference Optimization (Ismayilzada et al., 2025; background in ../diverge/reference/creative-preference-optimization.md). Same brainstorm-then-select discipline, run on a different model whose blind spots differ from Claude's.

Codex invocation mechanism

Plain Claude Code has no native codex:codex-rescue subagent. Every "ask Codex" step below means: use the Bash tool to call codex exec directly (the same mechanism paper-review-lite-codex uses). Requirements:

• < /dev/null — closes stdin. Without it, codex exec hangs on "Reading additional input from stdin…" even when the prompt is passed as a CLI argument. This is the single most common failure mode.
• --skip-git-repo-check so it runs regardless of git state, and --sandbox set per phase: read-only for brainstorming (no file writes), workspace-write for implementation.
• timeout: 600000 (10 min) on the Bash call as a backstop.

The result returns on stdout — read it directly from the Bash output. Treat a non-zero exit, or empty output, as a Codex failure: report it and offer to fall back to /diverge (Claude-only).

Steps

1. Take the task. Use $ARGUMENTS. If empty, ask the user what they want to solve.

2. Clarify if needed. If the task is ambiguous about the goal (not the implementation), ask one focused question before delegating. Skip if clear.

3. Brainstorm via Codex. Run the brainstorm prompt through codex exec (read-only sandbox), substituting TASK with the user's request verbatim:

   codex exec --sandbox read-only --skip-git-repo-check "$(cat <<'CODEXEOF'
   <brainstorm prompt template below, with TASK substituted>
   CODEXEOF
   )" < /dev/null
   

4. Present approaches to the user verbatim — do not paraphrase or filter them. Ask which to pursue, or whether to synthesize.

5. Implement via Codex. Run the implementation prompt through codex exec (workspace-write sandbox, -C set to the project directory), substituting TASK and SELECTED_APPROACH:

   codex exec --sandbox workspace-write --skip-git-repo-check -C "<project dir>" "$(cat <<'CODEXEOF'
   <implementation prompt template below, with TASK and SELECTED_APPROACH substituted>
   CODEXEOF
   )" < /dev/null
   

Brainstorm prompt template

<task>
Before implementing, generate 3–5 conceptually distinct approaches to:

TASK

Label each approach:
  [Novel]       — different conceptual basis from the conventional solution
  [Surprising]  — violates the obvious assumption; not the first answer
  [Diverse]     — maximally different from the other options in this list
  [Conventional]— the expected path, for contrast

For each approach provide:
- Core mechanism (1 sentence)
- How it works and what makes it distinct (2–3 sentences)
- Main tradeoff (1 sentence)

Do not implement. Present all approaches and stop.
</task>

<constraints>
At least one approach must be [Surprising].
At least one must be [Novel].
Approaches must differ in underlying mechanism, not just vocabulary.
Prioritize novelty and surprise over immediate quality.
Do not write any implementation code.
</constraints>

<structured_output_contract>
Numbered list only. No preamble. No implementation code.
Format each: number, label, mechanism line, explanation, tradeoff line.
</structured_output_contract>

Implementation prompt template

<task>
Implement the following approach to: TASK

Selected approach: SELECTED_APPROACH

Implement it fully. Edit files in place where applicable.
</task>

Notes

• Always brainstorm first — never ask Codex to implement on the first delegation.
• Do not inject your own implementation preferences — let Codex generate the approaches.
• Present Codex's approaches verbatim; do not paraphrase or filter them.
• If Codex is unavailable or errors, fall back to /diverge (Claude-only).