Codex Architect Skill (Third Brain)

Codex Architect Skill (Third Brain)

Trigger

• Keywords: architecture design, solution evaluation, tech selection, third brain, Codex advice, design consulting, ask Codex, second opinion

When NOT to Use

• Code implementation (use /​codex-implement)
• Code review (use /​codex-review)
• Deep discussion/​exhaustive exploration (use /​codex-brainstorm)

Usage

/​codex-architect "<question>"
/​codex-architect "Evaluate this design" --context src/​xxx.ts --mode review
/​codex-architect "Redis vs MongoDB?" --mode compare

Modes

Core Principle

User -> Claude -> Codex -> Integrate
          |         |         |
    Initial thinking  Third perspective  Combined advice

Codex Prompt Template

When using mcp__codex__codex, must include the following:

mcp__codex__codex({
  prompt: `You are a senior architect. Please provide architecture advice for the following question.

## Question
${QUESTION}

## Mode
${MODE} (design/​review/​compare)

## IMPORTANT: You must independently research the project

Before providing architecture advice, you **must** perform the following research:

### Research Steps
1. Understand project structure: \`ls src/\`, \`ls src/​service/\`, \`ls src/​provider/\`
2. Search related modules: \`grep -r "keyword" src/ --include="*.ts" -l | head -10\`
3. Read existing implementations: \`cat <relevant files> | head -150\`
4. Understand existing architecture patterns and conventions

### Verification Focus
- What does the existing architecture look like?
- What are the existing code style and patterns?
- What similar features can be referenced?

## Output Requirements

1. First describe which files you researched
2. Provide advice based on current project state
3. Consider consistency with existing architecture

...(other review dimensions)`,
  sandbox: 'read-only',
  'approval-policy': 'never',
});

Workflow Integration

/​codex-architect -> /​tech-spec -> /​review-spec -> /​codex-implement -> /​codex-review-fast
    Design           Plan          Review          Implement          Code Review

Verification

• Report includes Codex advice + Claude perspective
• Consensus and divergence points clearly marked
• Final recommendation integrates both perspectives

References

• references/​project-knowledge.md - Project architecture knowledge + report template

Examples

Input: /​codex-architect "How to design a high-concurrency cache?"
Action: Codex analysis -> Claude supplement -> Integrated output

Input: /​codex-architect "Any issues with this API design?" --mode review
Action: Codex evaluation -> Claude verification -> Output issues + recommendations