Grounded Docs is an MCP server that builds a local, version-aware index of documentation from websites, code repositories, package registries, local files, and archives for AI coding assistants. It helps assistants retrieve current project-specific documentation and supports MCP-compatible clients such as Claude, Cline, and similar tools. The catalogue add-ons provide skills, commands, and instructions for working with this documentation server.
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.
npx skills add arabold/docs-mcp-server --skill fetch-urlgit clone --depth 1 https://github.com/arabold/docs-mcp-serverWrote 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.
[](https://agentmods.dev/skills/arabold/docs-mcp-server/fetch-url)<a href="https://agentmods.dev/skills/arabold/docs-mcp-server/fetch-url"><img src="https://agentmods.dev/badge/skills/arabold/docs-mcp-server/fetch-url/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/arabold/docs-mcp-server/fetch-url"><img src="https://agentmods.dev/badge/skills/arabold/docs-mcp-server/fetch-url.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 7 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium MCP Rug Pull · line 7 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 29 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 53 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 56 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 60 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 63 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 80 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00051 | $0.00842 |
| Opus 5.5 | $0.00020 | $0.00337 |
| Sonnet 5.5 | $0.00010 | $0.00168 |
| Haiku 4.5 | $0.00005 | $0.00084 |
Grade A, and why
fetch-url 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.
How it starts
The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Fetch URL
Fetch one URL and print its content as Markdown. Nothing is added to the documentation index.
When to use
- You need to read a single web page as Markdown.
- You want to look at a documentation page before deciding whether to index it.
- You need the text of a URL for summarizing or analysis.
To index content for repeated searching, use the docs-manage skill
(scrape command) instead.
Command
npx @arabold/docs-mcp-server@latest fetch-url <url> [options]
<url> is an http://, https:// or file:// URL.
| Flag | Default | Description |
|---|---|---|
--no-follow-redirects |
follows redirects | Fail on an HTTP redirect instead of following it |
--scrape-mode auto|fetch|playwright |
auto |
How HTML pages are processed |
--header "Name: Value" |
Custom HTTP header (repeatable) | |
--quiet |
Log errors only | |
--verbose |
Log debug output |
Scrape modes
| Mode | Behavior |
|---|---|
auto |
Default. Renders HTML pages in headless Chromium, like playwright. |
playwright |
Renders HTML pages in headless Chromium, so content built by JavaScript is included. |
fetch |
Converts the HTML as the server sent it. Faster, but misses content built by JavaScript. |
In every mode, a site that refuses the plain request (HTTP 403 or 429) is fetched again through the browser.
Examples
# Fetch a documentation page
npx @arabold/docs-mcp-server@latest fetch-url https://react.dev/reference/react/useEffect
# Send an auth header
npx @arabold/docs-mcp-server@latest fetch-url https://docs.example.com/api \
--header "Authorization: Bearer tok_xxx"
# Skip browser rendering for a static page
npx @arabold/docs-mcp-server@latest fetch-url https://example.com/docs/page.html --scrape-mode fetch
# Fail instead of following a redirect
npx @arabold/docs-mcp-server@latest fetch-url https://example.com/old-page --no-follow-redirects
Output
The content goes to stdout. HTML pages and documents such as PDF or Word
files are converted to Markdown. JSON, XML and plain text are printed
unchanged. The --output flag has no effect on this command.
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 Changed · +10 lines · +6 tokens per session 4b93cd2d22cd
- 1mo ago First seen · 84 lines · 45 tokens per session scan A d4c068a66688
fetch-url is a skill published in the GitHub repository arabold/docs-mcp-server (1,817 stars, last pushed today), licensed MIT. It adds 51 tokens to every session and 842 once invoked, about $0.0002 per session on Opus 5.5. 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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