agentmods.dev

codex

codex is an agent for Claude Code from roarista/awesome-harness. It costs 68 tokens per session (1,351 once invoked), scanned A, original, MIT.

A coding worker that sends one clearly defined unit of work to Codex, an AI coding tool, which edits files and returns the resulting changes.

In plain words
What is it for?
Building one feature, fix, refactor, or module at a time from a written specification, with a runnable check when none is provided.
Why use it?
It separates planning and dispatch from implementation and makes clear that a task is unfinished until an actual file change exists.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter; reads .claude/ paths; runs codex exec.

not rated 1repo changed 23d ago A scan 68 tokens original MIT

Good fit Building one feature, fix, refactor, or module at a time from a written specification, with a runnable check when none is provided.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/roarista/awesome-harness/codex
View source ↗ roarista/awesome-harness
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.

Clone the repo
git clone --depth 1 https://github.com/roarista/awesome-harness

Made for: Claude Code.

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

README.md
[![agentmods](https://agentmods.dev/badge/agents/roarista/awesome-harness/codex/github.svg)](https://agentmods.dev/agents/roarista/awesome-harness/codex)
Your own site
<a href="https://agentmods.dev/agents/roarista/awesome-harness/codex"><img src="https://agentmods.dev/badge/agents/roarista/awesome-harness/codex/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for codex

Your own site · 80×15
<a href="https://agentmods.dev/agents/roarista/awesome-harness/codex"><img src="https://agentmods.dev/badge/agents/roarista/awesome-harness/codex.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 68 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,351 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00068 $0.01351
Opus 5.5 $0.00027 $0.00540
Sonnet 5.5 $0.00014 $0.00270
Haiku 4.5 $0.00007 $0.00135

Measured 23d ago against content hash 3c2e0d443202, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

codex 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 23d 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.

agents/codex.md · 93 lines

How it starts

The opening of the file, as written. The whole thing — 93 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the BUILDER. You dispatch exactly ONE unit to GPT via codex exec and stop.

Non-negotiable

  • You have no Read/Write/Edit/Glob/Grep tools. The ONLY way to change a file is codex exec. You are physically unable to write code in Claude — do not try, and never report BUILT-BY: self.
  • A build is DONE only when a real diff exists on disk. A receipt, a task id, a "handed off to the runtime" message, or a background job reference is NOT done. If you ever find yourself returning one, the unit FAILED — say so.
  • Never git commit, never git push, never touch .northstar.md.
  • Structure is the orchestrator's: codex creates/splits exactly what the unit's FILE PLAN names, nothing unplanned. If a file would exceed its line budget, return STATUS: FAILED with the reason; do not split it.
  • Work only inside the repo cwd. Smallest diff that satisfies GOAL (Ponytail).

Procedure

  1. Read the spec (CONTEXT / CHANGE / GOAL / VERIFY). If VERIFY is missing, invent one runnable check.
  2. Dispatch via codex-companion plugin:
    • Resolve: CODEX_PLUGIN_ROOT="$(ls -d "$HOME"/.claude/plugins/cache/openai-codex/codex/*/ | sort -V | tail -1)"
    • cd into target repo root (sandbox = cwd)
    • Run: node "$CODEX_PLUGIN_ROOT/scripts/codex-companion.mjs" task --write --model gpt-6.1-sol --effort <EFFORT> "<spec>" (Ro 2026-10-14: every Codex run is gpt-6.1-sol. = the spec's EFFORT line, else medium; max → xhigh.)
    • Fallback to codex exec -C <root> -m gpt-6.1-sol -c model_reasoning_effort=<EFFORT> only if plugin path missing
    • Multi-root units: run once per root via codex-companion, never fall back to editing in Claude
  3. VERIFY: run the check (py_compile / test / script) via Bash. Paste its real output.
  4. Confirm the diff exists: git status --porcelain and git diff --stat.

Return contract — EXACTLY 8 lines, no preamble

UNIT: STATUS: DONE | FAILED FILES: DIFFSTAT: <git diff --stat one-liner> VERIFY: <command run + its real result> BUILT-BY: codex-companion (one call per root) DEVIATIONS: <anything you did differently from the spec, or none> NEXT: <one thing, or none>

Read the full file on GitHub · 93 lines

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. 23d ago Changed · +1 lines 3c2e0d443202
  2. 1mo ago Changed · +5 lines · -174 tokens per session cc1a3a39a3ad
  3. 2mo ago First seen · 87 lines · 242 tokens per session scan A b2dbb35d948e

Subscribe to this mod's changes

codex is an agent published in the GitHub repository roarista/awesome-harness (1 stars, last pushed 4d ago), licensed MIT. It adds 68 tokens to every session and 1,351 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-08-31.

Building agents
Related

codex compared with agents from other repositories

codex next to 6 agents from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
codexroarista/awesome-harnessAgent14d agoMITA68Claude Code
playwright-test-generatormicrosoft/playwrightAgent99ktodayApache-2.0A151Claude Code
.NET-Notebook-Migration-Agentmicrosoft/ai-agents-for-beginnersAgent79ktodayMITA33Claude Code
code-revieweranthropics/claude-cookbooksAgent54k2d agoMITA52Claude Code
AVM Owner Triagegithub/awesome-copilotAgent41ktodayMITA61Claude Code
Ultimate Transparent Thinking Beast Modegithub/awesome-copilotAgent41ktodayMITA11Claude Code
WinForms Expertgithub/awesome-copilotAgent41ktodayMITA19Claude Code