What is mainframe-skills?

A plugin package containing one add-on called review-as. It studies a GitHub user's past code-review comments and uses that style when reviewing changes in chat.

Use it to review a change as a selected GitHub user, based on up to a year of their review comments.

It helps produce reviews that match a particular reviewer's known preferences without posting anything to GitHub.

mainframe-skills — Plugin by mainframecomputer

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.

Claude Code

/plugin marketplace add mainframecomputer/skills

agentmods

npx agentmods add plugins/mainframecomputer/skills/marketplace

Clone the repo

git clone --depth 1 https://github.com/mainframecomputer/skills

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.

When invoked not measured Not applicable: nothing here is loaded into a session.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

mainframe-skills 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 yesterday.

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.

.claude-plugin/marketplace.json · 21 lines

What it actually says

{
  "name": "mainframe-skills",
  "owner": {
    "name": "Mainframe",
    "url": "https://github.com/mainframecomputer"
  },
  "metadata": {
    "description": "Agent skills from the Mainframe team",
    "version": "0.1.0"
  },
  "plugins": [
    {
      "name": "review-as",
      "description": "Learn how a GitHub user reviews code from up to a year of their real review comments, then review a change as that person — in chat only, never posted to GitHub.",
      "source": "./",
      "strict": false,
      "skills": ["./skills/review-as"]
    }
  ]
}

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.

yesterday First seen · 21 lines scan A c263c2802d9b

Subscribe to this mod's changes

mainframe-skills is a plugin published in the GitHub repository mainframecomputer/skills (6 stars, last pushed 1mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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.

Code review agent-skills claude-code

mainframe-skills

Getting it into your agent

Grade A, and why

Nothing flagged

What it actually says

What this file has done since we first saw it

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