web-fetch
Fetches web content as clean markdown by preferring markdown-native responses and falling back to selector-based HTML extraction. Use for documentation, articles, and reference pages at http/https URLs.
How do I install this agent skill?
npx skills add https://github.com/0xbigboss/claude-code --skill web-fetchIs this agent skill safe to install?
- Gen Agent Trust Hubpass
The web-fetch skill allows for the extraction of web content into markdown format but lacks safeguards against Indirect Prompt Injection and Server-Side Request Forgery (SSRF) when processing untrusted external URLs and content.
- Socketpass
No alerts
- Snykwarn
Risk: MEDIUM · No issues
- Runlayerpass
1/4 files flagged
What does this agent skill do?
Web Content Fetching
Fetch web content in this order:
- Prefer markdown-native endpoints (
content-type: text/markdown) - Use selector-based HTML extraction for known sites
- Use the bundled Bun fallback script when selectors fail
Prerequisites
Verify required tools before extracting:
command -v curl >/dev/null || echo "curl is required"
command -v html2markdown >/dev/null || echo "html2markdown is required for HTML extraction"
command -v bun >/dev/null || echo "bun is required for fetch.ts fallback"
Install Bun dependencies for the bundled script:
cd ~/.claude/skills/web-fetch && bun install
Default Workflow
Use this as the default flow for any URL:
URL="<url>"
CONTENT_TYPE="$(curl -sIL "$URL" | awk -F': ' 'tolower($1)=="content-type"{print tolower($2)}' | tr -d '\r' | tail -1)"
if echo "$CONTENT_TYPE" | grep -q "markdown"; then
curl -sL "$URL"
else
curl -sL "$URL" \
| html2markdown \
--include-selector "article,main,[role=main]" \
--exclude-selector "nav,header,footer,script,style"
fi
Known Site Selectors
| Site | Include Selector | Exclude Selector |
|---|---|---|
| platform.claude.com | #content-container | - |
| docs.anthropic.com | #content-container | - |
| developer.mozilla.org | article | - |
| github.com (docs) | article | nav,.sidebar |
| Generic | article,main,[role=main] | nav,header,footer,script,style |
Example:
curl -sL "<url>" \
| html2markdown \
--include-selector "#content-container" \
--exclude-selector "nav,header,footer"
Finding the Right Selector
When a site isn't in the patterns list:
# Check what content containers exist
curl -s "<url>" | grep -o '<article[^>]*>\|<main[^>]*>\|id="[^"]*content[^"]*"' | head -10
# Test a selector
curl -sL "<url>" | html2markdown --include-selector "<selector>" | head -30
# Check line count
curl -sL "<url>" | html2markdown --include-selector "<selector>" | wc -l
Universal Fallback Script
When selectors produce poor output, run the bundled parser:
bun ~/.claude/skills/web-fetch/fetch.ts "<url>"
If already in the skill directory:
bun fetch.ts "<url>"
Options Reference
--include-selector "CSS" # Keep only matching elements
--exclude-selector "CSS" # Remove matching elements
--domain "https://..." # Convert relative links to absolute
Troubleshooting
Empty output with selectors: The page might be markdown-native. Check headers first:
curl -sIL "<url>" | grep -i '^content-type:'
Wrong content selected: The site may have multiple article/main regions:
curl -s "<url>" | grep -o '<article[^>]*>'
html2markdown not found: Install it, then retry selector-based extraction.
bun or script deps missing: Run cd ~/.claude/skills/web-fetch && bun install.
Missing code blocks: Check if the site uses non-standard code formatting.
Client-rendered content: If HTML only has "Loading..." placeholders, the content is JS-rendered. Neither curl nor the Bun script can extract it; use browser-based tools.
How can the creator link this skill?
Add the canonical catalog link to the repository README so users can inspect current installs and available audits. The publishing guide covers the complete discovery path.
<a href="https://skillzs.dev/skills/0xbigboss/claude-code/web-fetch">View web-fetch on skillZs</a>