tools-plus-plus MCP server

tools++

An MCP server with 55 small tools that add to the ones Claude already has, so everyday tasks get simpler and take fewer steps: a calculator that doesn't round, a calendar that knows German holidays, CSV and SQLite queries, PDF text, archives, ports, ffmpeg helpers and so on.

I built this because Claude kept doing arithmetic in its head, guessing today's date and writing a new throwaway script every time it had to look at a CSV. Now it just calls a tool.

Nothing here replaces Claude's own tools. Files, shell commands and web search stay with them. tools++ covers what's left: the things Claude would otherwise guess, estimate or script by hand.

No dependencies, only Node.js. Runs on Windows, macOS and Linux. Tool schemas are loaded when a tool is first needed, so having the plugin installed costs almost nothing.

Setup

1. Install Node.js

You need Node.js 20.3 or newer (22.5+ if you want the sqlite tool). Get it from nodejs.org and check that it works:

node --version

2. Optional: install ffmpeg

Only the media tools need it. Everything else works without it.

winget install Gyan.FFmpeg     # Windows
brew install ffmpeg            # macOS
sudo apt install ffmpeg        # Debian/Ubuntu

3. Add the plugin to Claude Code

Run these two commands inside Claude Code:

/plugin marketplace add Kessler833/tools-plus-plus
/plugin install tools-plus-plus@tools-plus-plus

4. Check that it works

Start a new session (or run /reload-plugins) and ask something like "what's 2^100 exactly?" or "how many working days are left this year in Bavaria?". Claude should call calc or holidays instead of answering from memory.

Other MCP clients

It's a normal stdio MCP server, so it also works in Claude Desktop, Cursor, VS Code, Windsurf, Cline, Zed, Codex CLI, Gemini CLI etc. Clone the repo:

git clone https://github.com/Kessler833/tools-plus-plus.git

and add this to the client's MCP config, with the path to where you cloned it:

{
  "mcpServers": {
    "tools-plus-plus": {
      "command": "node",
      "args": ["/path/to/tools-plus-plus/server/index.mjs"]
    }
  }
}

ChatGPT can't use it directly, since it only connects to remote (HTTP) MCP servers.

Or just ask your AI agent

Paste this into Claude Code, Cursor or whatever agent you use:

Install the tools++ MCP server from https://github.com/Kessler833/tools-plus-plus for me and check that it works.

Tools

Math

Tool
calc	Exact math with fractions and big integers (0.1 + 0.2 is 0.3, 1000! works), percent, variables. Says when a result is only approximate.
solve	Linear equations and systems exactly, real roots of nonlinear equations
matrix	Determinant, inverse, rank, rref etc. with exact fractions
number_theory	Prime test, factorization, divisors, base conversion
finance	Compound interest, loans with amortization, NPV, IRR, CAGR
stats	Mean, median, sd, quartiles, outliers, histogram, correlation, regression. Works on lists and CSV columns.
convert_units	Units (also things like km/h or L/100km to mpg), temperatures, currencies (ECB rates)
random	Random numbers, picks, shuffles, UUIDs, passwords, dice

Dates

Tool
time_now	Current date and time, ISO week, other time zones
time_convert	Time zone conversion, handles DST gaps
date_diff, date_add	Differences and date math, business days
holidays	Public holidays (DE with all states, AT, CH, US, GB, FR, others online), business days without holidays
calendar	Month view, "last friday of november", ISO weeks
cron	Explains a cron expression and lists the next runs

Text and data

Tool
text_stats	Words, characters, tokens, reading time, hidden characters, mixed line endings
text_transform	camelCase/snake_case/slugs, sort, dedupe, wrap, Unicode cleanup
token_count	Rough token count of a file or folder
diff	Line diff or word/char diff
regex	Test a regex, see groups and replacements. Hanging patterns get killed after a timeout.
extract	Pull URLs, emails, dates, amounts etc. out of text
markdown	Lint, table of contents, link check, table formatting
encode, hash	base64, URL, HTML, JWT and so on, checksums
json, schema	Validation with line/column, queries, JSON Schema
table, table_convert	Filter, group and join CSV/JSON/Markdown tables, convert between formats
sqlite	Look into SQLite files (read-only)
pdf_text	Text of a PDF per page, or search in it
color	Color conversions, contrast check, palettes

Files and system

Tool
disk_usage	What takes up the space in a folder
find_duplicates	Identical files (doesn't delete anything)
batch_rename	Rename many files with a preview and undo
archive	zip, tar, tar.gz, gz. Refuses paths that would escape the target folder.
snapshot	Save a folder's state before risky changes and restore it
secret_scan	Finds API keys and passwords before you commit them
env_compare	.env against .env.example
log_summary	Errors first, then the most common lines of a log
processes	Which process uses port 3000, process list, kill
sysinfo	OS, CPU, RAM, disk space, installed dev tools
run_parallel	Run several commands at once
benchmark	Time commands and compare them
wait_for	Wait for a file, port, URL or process
deps_check	Outdated and deprecated packages in package.json, requirements.txt, pyproject.toml, Cargo.toml

Web

Tool
http	Send a request, see status, timing and response
net	DNS, port reachability, TLS certificate expiry
package_info	Latest version of an npm/PyPI/crates package or GitHub repo
weather	Weather via Open-Meteo
wikipedia	Wikipedia summaries

Media (needs ffmpeg)

Tool
media_info	Codec, resolution, duration etc.
video_frames	Pulls frames out of a video so Claude can actually look at it
audio_analyze	Loudness, clipping, silence, waveform image
image_compare	Pixel diff between two images
image_edit	Resize, crop, rotate, convert

What goes online

Everything runs locally. These tools make network requests, and only when they're called: convert_units for currencies (frankfurter.dev), holidays for countries that aren't built in (date.nager.at), package_info and deps_check (npm, PyPI, crates.io, GitHub), weather (open-meteo.com), wikipedia, and http, net and wait_for for whatever address you give them.

Development

node test/run.mjs            # tests, offline
node test/run.mjs --online   # including the web tools

Each tool is one entry in server/tools.mjs, the code lives in server/lib/.

License

MIT © Hannes Kapsch