What is firstch-tools?

A collection of small developer tools available through MCP, a standard way for coding agents to call external tools. It covers tasks involving web content, text, code, data formats, images, security values, and time conversions.

Use it for accessibility contrast checks, WebP conversion, JSON-LD and robots.txt creation, formatting, encoding, hashing, JWT checks, QR codes, UUIDs, timestamps, SQL, Markdown tables, and related utilities.

It keeps many routine conversions, checks, and generators in one tool collection instead of requiring separate scripts or websites.

firstch-tools — Plugin for Claude Code by First-CH/firstch-tools-mcp

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.

Clone the repo

git clone --depth 1 https://github.com/First-CH/firstch-tools-mcp

Made for: Claude Code.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/plugins/first-ch/firstch-tools-mcp/firstch-tools/github.svg)](https://agentmods.dev/plugins/first-ch/firstch-tools-mcp/firstch-tools)

Your own site

<a href="https://agentmods.dev/plugins/first-ch/firstch-tools-mcp/firstch-tools"><img src="https://agentmods.dev/badge/plugins/first-ch/firstch-tools-mcp/firstch-tools/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.

Your own site · 80×15

<a href="https://agentmods.dev/plugins/first-ch/firstch-tools-mcp/firstch-tools"><img src="https://agentmods.dev/badge/plugins/first-ch/firstch-tools-mcp/firstch-tools.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

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. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Security

Grade A, and why

firstch-tools 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 today.

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.

plugins/firstch-tools/.claude-plugin/plugin.json · 14 lines

What it actually says

{
  "name": "firstch-tools",
  "displayName": "First CH Tools",
  "version": "0.42.1",
  "description": "44 local MCP tools for web production and development work, from the free browser tools at tools.first-ch.com: WCAG contrast checks, Japanese character / X-weight counting, WebP conversion, JSON-LD, llms.txt and robots.txt generation, Marp slides, encoding and format conversion (JSON/YAML/CSV/Markdown tables), wiki-export checks for duplicates, orphan pages and inconsistent terms, fitting Japanese addresses into printed boxes, and everyday developer utilities. They run on your machine via npx and send nothing. Plus 36 app_* tools (off by default; enable with FIRSTCH_ENABLE_APPS=1) that call the web apps at apps.first-ch.com and send their input (a URL, domain or text) there; the apps store nothing.",
  "author": {
    "name": "First CH LLC",
    "url": "https://first-ch.com"
  },
  "homepage": "https://tools.first-ch.com",
  "repository": "https://github.com/First-CH/firstch-tools-mcp",
  "license": "MIT"
}

Contents

What it installs

The manifest is a name and a version. 1 MCP server travel with it, and installing the plugin installs all of them. Each is measured on its own page, and each can be installed alone.

MCP server firstch-tools A not measured

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.

today Changed 8656f97eb725
2d ago Changed 92532248ae8f
3d ago Changed 73c2603d17ab
10d ago Changed 13b8332dac36
22d ago Changed 40c1792a3d16
23d ago Changed 1f89314859cf
29d ago Changed cc2c4184b50a
1mo ago Changed bfba8d47f267
1mo ago Changed 2ad20e57cb8a
1mo ago First seen · 14 lines scan A f45db7b6df29

Subscribe to this mod's changes

firstch-tools is a plugin published in the GitHub repository First-CH/firstch-tools-mcp (0 stars, last pushed today), 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.

firstch-tools

Getting it into your agent

Wrote this? Show the measurements

Grade A, and why

Nothing flagged

What it actually says

What it installs

What this file has done since we first saw it

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