gh-cli

gh-cli

A Claude Code plugin that intercepts GitHub URL fetches and redirects Claude to use the authenticated gh CLI instead.

Problem

Claude Code's WebFetch tool, MCP fetch tools (Exa's web_fetch_exa and similar), and Bash curl/wget commands don't use the user's GitHub authentication. This means:

• Private repos: Fetches fail with 404 errors
• Rate limits: Unauthenticated requests are limited to 60/hour (vs 5,000/hour authenticated)
• Missing data: Some API responses are incomplete without authentication

Solution

This plugin provides:

1. PreToolUse hooks that intercept GitHub URL access via WebFetch, MCP fetch/scrape/crawl/extract tools, or curl/wget, and suggest the correct gh CLI command
2. A gh PATH shim that blocks anti-patterns: API /contents/ fetching and non-session-scoped temp directory clones
3. A SessionEnd hook that automatically cleans up cloned repositories when the session ends

What Gets Intercepted

The fetch hook matches WebFetch plus any MCP tool whose name contains fetch, scrape, crawl, or extract — mcp__exa__web_fetch_exa, mcp__firecrawl__firecrawl_scrape, mcp__tavily__tavily_extract, and equivalents from other MCP servers. Web tools named something else entirely (browser navigation, for instance) are not covered; hooks/matcher.bats records exactly which names match.

It reads both fetch payload shapes — WebFetch's single url, and the urls field MCP fetch tools use to batch several pages into one call, whether that field arrives as an array or a bare string. Because a tool call is atomic, one GitHub URL anywhere in a batch denies the whole call; the denial names each offending URL alongside its suggestion. WebFetch's prompt field is deliberately not scanned, so a prompt that merely mentions a GitHub URL is not denied.

Tool	Pattern	Suggestion
WebFetch, MCP fetch	github.com/{owner}/{repo}	gh repo view owner/repo
WebFetch, MCP fetch	github.com/.../blob/...	gh repo clone + Read
WebFetch, MCP fetch	github.com/.../tree/...	gh repo clone + Read/Glob/Grep
WebFetch, MCP fetch	github.com/.../pull/{n}	gh pr view
WebFetch, MCP fetch	github.com/.../issues/{n}	gh issue view
WebFetch, MCP fetch	github.com/.../releases/download/...	gh release download
WebFetch, MCP fetch	api.github.com/repos/.../pulls	gh pr list / gh pr view
WebFetch, MCP fetch	api.github.com/repos/.../issues	gh issue list / gh issue view
WebFetch, MCP fetch	api.github.com/repos/.../contents/...	gh repo clone + Read
WebFetch, MCP fetch	api.github.com/repos/.../releases	gh release list
WebFetch, MCP fetch	api.github.com/repos/.../actions	gh run list
WebFetch, MCP fetch	api.github.com/... (anything else)	gh api <endpoint>
WebFetch, MCP fetch	raw.githubusercontent.com/...	gh repo clone + Read
WebFetch, MCP fetch	gist.github.com/...	gh gist view
Bash	curl https://api.github.com/...	gh api <endpoint>
Bash	curl https://raw.githubusercontent.com/...	gh repo clone + Read
Bash	wget https://github.com/...	gh release download
Bash (shim)	gh api repos/.../contents/...	gh repo clone + Read
Bash (shim)	gh repo clone ... /tmp/... (non-session-scoped)	Session-scoped clone path

What Passes Through

• Non-GitHub URLs (any domain that isn't github.com, api.github.com, raw.githubusercontent.com, or gist.github.com)
• GitHub Pages sites (*.github.io)
• Commands already using gh (except anti-patterns blocked by the shim; see table above)
• Git commands (git clone, git push, etc.)
• Search commands that mention GitHub URLs (grep, rg, etc.)

Note: When hooks deny blob/tree/raw URLs, the denial message explicitly warns against using gh api to fetch and base64-decode file contents as a fallback — clone the repo instead.

Automatic Cleanup

Cloned repositories are stored in session-scoped temp directories ($TMPDIR/gh-clones-<session-id>/). A SessionEnd hook automatically removes them when the session ends, so there's no manual cleanup needed and concurrent sessions don't interfere with each other.

Prerequisites

• GitHub CLI (gh) must be installed and authenticated (gh auth login)
• If gh is not installed, the hooks pass through without disruption

Installation

/plugin marketplace add trailofbits/skills
/plugin install gh-cli