# Explainer

Explain a GitHub issue or pull request at 100, 200, and 300 level.

- Repository: https://github.com/agentic-community/mcp-gateway-registry (1032 stars)
- Category: Git and review
- License: Apache-2.0
- Last updated: 2026-11-01
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add agentic-community/mcp-gateway-registry --skill explainer -g -a claude-code -y`
Codex: `npx skills add agentic-community/mcp-gateway-registry --skill explainer -g -a codex -y`
Cursor: `npx skills add agentic-community/mcp-gateway-registry --skill explainer -g -a cursor -y`
Gemini CLI: `npx skills add agentic-community/mcp-gateway-registry --skill explainer -g -a gemini-cli -y`

## Description

Explain a GitHub issue or pull request at 100, 200, and 300 level. Verifies every claim against the code, then writes a markdown and a self-contained HTML version into .scratchpad/issue-NNNN/ or .scratchpad/pr-NNNN/ and opens it for preview. Starts no server; offers a command for anyone who wants one. Use when asked to explain, write up, or produce an explainer for an issue or PR.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Explainer Skill

Turn a GitHub issue or pull request into an explainer a colleague can read at whatever depth they need. Three levels, one document: 100 for anyone, 200 for how it works, 300 for the code.

Apply the [writing](../writing/SKILL.md) skill to every word of prose. Invoke it, then run its revision pass before you write the file. No emojis and no em-dashes anywhere, per the repo rules.

## Inputs

Accept any of these and resolve to a number plus a kind:

- A full URL: `https://github.com/agentic-community/mcp-gateway-registry/issues/1832`
- A PR URL: `.../pull/1711`
- A bare reference: `#1832`, `1832`, `owner/repo#1832`

A URL containing `/pull/` is a PR. Everything else needs a check, because `gh issue view` succeeds on PRs too. Run `gh pr view <n> --json number` and treat a clean exit as a PR.

Write output to `.scratchpad/issue-NNNN/` or `.scratchpad/pr-NNNN/`. Create it with `mkdir -p`. `.scratchpad/` is gitignored, so nothing you write here can be committed.

## Step 1: gather

For an issue:

```bash
gh issue view <n> --json number,title,state,labels,author,createdAt,body,comments
```

For a PR, get the discussion and the diff:

```bash
gh pr view <n> --json number,title,state,author,createdAt,body,comments,files,additions,deletions,baseRefName,headRefName
gh pr diff <n>
```

Record the commit you verified against, and use it to pin every code link:

```bash
git rev-parse --short HEAD
```

## Step 2: verify before you explain

This step is what separates a useful explainer from a paraphrase. Do not restate the author's claims. Check them.

For every factual claim in the issue or PR body:

The rest: https://github.com/agentic-community/mcp-gateway-registry/blob/HEAD/.claude/skills/explainer/SKILL.md