coding-agent

A way to run Codex CLI, Claude Code, OpenCode, or Pi Coding Agent from a terminal, including as background processes.

In plain words
What is it for?
Use it to launch coding agents in a chosen working directory, set time limits, run them in the background, and monitor their sessions.
Why use it?
It provides the terminal setup these interactive coding programs need and allows longer jobs to be monitored separately.

Skill for Claude CodeCodex

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/metaspartan/cybara/coding-agent
Any agent
npx skills add metaspartan/cybara --skill coding-agent
Clone the repo
git clone --depth 1 https://github.com/metaspartan/cybara

Made for: Claude Code, Codex.

Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,427 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
Origin 83% copy Near-identical to another mod 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 $0.00026 $0.02427
Opus 5 $0.00013 $0.01213
Sonnet 5 $0.00005 $0.00485
Haiku 4.5 $0.00003 $0.00243

Measured 2d ago against content hash 3cff4eae4e4b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

coding-agent scanned grade B with 1 finding 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 2d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

**Model:** `gpt-5.2-codex` is the default (set in ~/.codex/config.toml)
Origin

This is a copy

83% identical to coding-agent — 100 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/coding-agent/SKILL.md · 279 lines

How it starts

The opening of the file, as written. The whole thing — 279 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Coding Agent (bash-first)

Use bash (with optional background mode) for all coding agent work. Simple and effective.

⚠️ PTY Mode Required!

Coding agents (Codex, Claude Code, Pi) are interactive terminal applications that need a pseudo-terminal (PTY) to work correctly. Without PTY, you'll get broken output, missing colors, or the agent may hang.

Always use pty:true when running coding agents:

# ✅ Correct - with PTY
bash pty:true command:"codex exec 'Your prompt'"

# ❌ Wrong - no PTY, agent may break
bash command:"codex exec 'Your prompt'"

Bash Tool Parameters

Parameter Type Description
command string The shell command to run
pty boolean Use for coding agents! Allocates a pseudo-terminal for interactive CLIs
workdir string Working directory (agent sees only this folder's context)
background boolean Run in background, returns sessionId for monitoring
timeout number Timeout in seconds (kills process on expiry)
elevated boolean Run on host instead of sandbox (if allowed)

Process Tool Actions (for background sessions)

Action Description
list List all running/recent sessions
poll Check if session is still running
log Get session output (with optional offset/limit)
write Send raw data to stdin
submit Send data + newline (like typing and pressing Enter)
send-keys Send key tokens or hex bytes
paste Paste text (with optional bracketed mode)
kill Terminate the session

Quick Start: One-Shot Tasks

For quick prompts/chats, create a temp git repo and run:

# Quick chat (Codex needs a git repo!)
SCRATCH=$(mktemp -d) && cd $SCRATCH && git init && codex exec "Your prompt here"

# Or in a real project - with PTY!
bash pty:true workdir:~/Projects/myproject command:"codex exec 'Add error handling to the API calls'"

Why git init? Codex refuses to run outside a trusted git directory. Creating a temp repo solves this for scratch work.

Read the full file on GitHub · 279 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. 2d ago First seen · 279 lines · 26 tokens per session scan B 3cff4eae4e4b

Subscribe to this mod's changes

coding-agent is a skill published in the GitHub repository metaspartan/cybara (23 stars, last pushed 3d ago), licensed MIT. It adds 26 tokens to every session and 2,427 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). It is 83% identical to coding-agent, differing in 100 lines, and is treated as a copy.