coding-agent

coding-agent is a skill for Claude Code, Codex from mastra-ai/mastra. It costs 81 tokens per session (1,938 once invoked), scanned A, original, no licence file.

A guide for building agents that write, edit, review, or refactor software code.

In plain words
What is it for?
Use it when creating an agent to write scripts, generate code, review pull requests, refactor code, fix bugs, or write tests.
Why use it?
It helps define how an agent should handle common programming tasks and requests.

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

Made for: Claude Code, Codex.

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 coding-agent

README.md
[![agentmods](https://agentmods.dev/badge/skills/mastra-ai/mastra/coding-agent.svg)](https://agentmods.dev/skills/mastra-ai/mastra/coding-agent)
Your own site
<a href="https://agentmods.dev/skills/mastra-ai/mastra/coding-agent"><img src="https://agentmods.dev/badge/skills/mastra-ai/mastra/coding-agent.svg" alt="Measured on agentmods" height="20"></a>
Per session 81 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,938 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00081 $0.01938
Opus 5 $0.00041 $0.00969
Sonnet 5 $0.00016 $0.00388
Haiku 4.5 $0.00008 $0.00194

Measured 5d ago against content hash d67d681277aa, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

coding-agent 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 5d 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.

packages/editor/src/ee/workspace/skills/coding-agent/SKILL.md · 141 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 5d ago First seen · 141 lines · 81 tokens per session scan A d67d681277aa

Subscribe to this mod's changes

coding-agent is a skill published in the GitHub repository mastra-ai/mastra (27,707 stars, last pushed today), with no licence file. It adds 81 tokens to every session and 1,938 once invoked, about $0.0004 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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