Codex

What it does

When your agent uses it

• Development work in your project

Example prompts

• “/codex”

Requirements

• Node.js
• A credential in OPENAI_API_KEY

Workflow steps

7 steps, taken from the first numbered list in SKILL.md.

1. 1Always use pty=true — Codex is an interactive terminal app and hangs without a PTY
2. 2Git repo required — Codex won't run outside a git directory. Use mktemp -d && git init for scratch
3. 3Use exec for one-shots — codex exec "prompt" runs and exits cleanly
4. 4sandbox workspace-write for building — auto-approves changes within the sandbox (--full-auto is deprecated for this)
5. 5Background for long tasks — use background=true and monitor with process tool
6. 6Don't interfere — monitor with poll/log, be patient with long-running tasks
7. 7Parallel is fine — run multiple Codex processes at once for batch work

What it can do on your machine

Read from SKILL.md and the folder at commit 0e37a43. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • git
  • codex
  • gh
  • npm

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • github.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • OPENAI_API_KEY

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Codex loads about 1.5k tokens when it runs. Until then it costs about 15 tokens; SKILL.md has 412 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~15

When it runs · the whole SKILL.md, loaded when a task matches

~1.5k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from NousResearch/hermes-agent at commit 0e37a43, republished under its MIT licence (© NousResearch). 412 words, ~1,459 tokens.

name

codex

description

Delegate coding to OpenAI Codex CLI (features, PRs).

version

1.0.1

author

Hermes Agent

license

MIT

platforms

linux, macos, windows

terminal(command="codex exec 'Add dark mode toggle to settings'", workdir="~/project", pty=true)

terminal(command="cd $(mktemp -d) && git init && codex exec 'Build a snake game in Python'", pty=true)

# Start in background with PTY
terminal(command="codex exec --sandbox workspace-write 'Refactor the auth module'", workdir="~/project", background=true, pty=true)
# Returns session_id

# Monitor progress
process(action="poll", session_id="<id>")
process(action="log", session_id="<id>")

# Send input if Codex asks a question
process(action="submit", session_id="<id>", data="yes")

# Kill if needed
process(action="kill", session_id="<id>")

codex exec --sandbox danger-full-access "<task>"

terminal(command="REVIEW=$(mktemp -d) && git clone https://github.com/user/repo.git $REVIEW && cd $REVIEW && gh pr checkout 42 && codex review --base origin/main", pty=true)

# Create worktrees
terminal(command="git worktree add -b fix/issue-78 ~/.hermes/cache/scratch/issue-78 main", workdir="~/project")
terminal(command="git worktree add -b fix/issue-99 ~/.hermes/cache/scratch/issue-99 main", workdir="~/project")

# Launch Codex in each
terminal(command="codex --sandbox workspace-write exec 'Fix issue #78: <description>. Commit when done.'", workdir="~/.hermes/cache/scratch/issue-78", background=true, pty=true)
terminal(command="codex --sandbox workspace-write exec 'Fix issue #99: <description>. Commit when done.'", workdir="~/.hermes/cache/scratch/issue-99", background=true, pty=true)

# Monitor
process(action="list")

# After completion, push and create PRs
terminal(command="cd ~/.hermes/cache/scratch/issue-78 && git push -u origin fix/issue-78")
terminal(command="gh pr create --repo user/repo --head fix/issue-78 --title 'fix: ...' --body '...'")

# Cleanup
terminal(command="git worktree remove ~/.hermes/cache/scratch/issue-78", workdir="~/project")

# Fetch all PR refs
terminal(command="git fetch origin '+refs/pull/*/head:refs/remotes/origin/pr/*'", workdir="~/project")

# Review multiple PRs in parallel
terminal(command="codex exec 'Review PR #86. git diff origin/main...origin/pr/86'", workdir="~/project", background=true, pty=true)
terminal(command="codex exec 'Review PR #87. git diff origin/main...origin/pr/87'", workdir="~/project", background=true, pty=true)

# Post results
terminal(command="gh pr comment 86 --body '<review>'", workdir="~/project")

© NousResearch, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/autonomous-ai-agents/codex of NousResearch/hermes-agent.

Open the folder on GitHubat commit 0e37a43

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in NousResearch/hermes-agent, which our catalogue first saw on October 7, 2026.

• johnson7788/MultiUserClawhermes-agent/skills/autonomous-ai-agents/codex