codex-architect

codex-architect is a skill for Claude Code, Codex from sd0xdev/sd0x-harness. It costs 53 tokens per session (762 once invoked), scanned A, original, MIT.

An architecture consultation that gives design advice, reviews an existing design, or compares technical options with a second perspective from Codex.

In plain words
What is it for?
Use it when designing a feature, checking an architecture, comparing technologies, or asking for a second opinion on a proposed solution.
Why use it?
It helps clarify important design choices before implementation and can reveal risks or trade-offs that are easy to miss.

Skill for Claude CodeCodex

Part of the sd0x-dev-flow plugin — 40 skills, 16 agents, 5 hooks shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/sd0xdev/sd0x-harness/codex-architect
Any agent
npx skills add sd0xdev/sd0x-harness --skill codex-architect
Clone the repo
git clone --depth 1 https://github.com/sd0xdev/sd0x-harness

Made for: Claude Code, Codex.

Or install sd0x-dev-flow, the plugin that ships this one along with the rest of its 40 skills, 16 agents, 5 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for codex-architect

README.md
[![agentmods](https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/codex-architect.svg)](https://agentmods.dev/skills/sd0xdev/sd0x-harness/codex-architect)
Your own site
<a href="https://agentmods.dev/skills/sd0xdev/sd0x-harness/codex-architect"><img src="https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/codex-architect.svg" alt="Measured on agentmods" height="20"></a>
Per session 53 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 762 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00053 $0.00762
Opus 5 $0.00026 $0.00381
Sonnet 5 $0.00011 $0.00152
Haiku 4.5 $0.00005 $0.00076

Measured 4d ago against content hash 8bb6b81b9949, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codex-architect scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/codex-architect/SKILL.md · 112 lines

How it starts

The opening of the file, as written. The whole thing — 112 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

Mode Purpose When
design Provide design advice Starting from scratch (default)
review Evaluate existing design Validate solution, find issues
compare Compare multiple options Tech selection

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',
});

Read the full file on GitHub · 112 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 112 lines · 53 tokens per session scan A 8bb6b81b9949

Subscribe to this mod's changes

codex-architect is a skill published in the GitHub repository sd0xdev/sd0x-harness (188 stars, last pushed today), licensed MIT. It adds 53 tokens to every session and 762 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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