Polymath Megablaster Mcp

io.github.headlessherm-creatorPublished by GitHub account headlessherm-creatorv3.1.0Updated Oct 29, 2026

Local deterministic calc MCP: exact math, dates, unit conversion, stats, subnet math.

VerifiedSTDIODesktop onlyDeveloper ToolsData & Analytics

Overview

AI-generated overview

Local MCP server giving assistants exact, deterministic math, date, unit, statistics, subnet and UUID tools with no network calls.

What you can do
  • Evaluate arbitrary-precision math expressions, factorials, permutations and combinations, and compute statistics on number lists
  • Add, subtract and diff dates with business days and leap years, and convert times across IANA time zones
  • Convert units of length, weight, volume and temperature, and convert numbers between decimal, hex, binary and octal
  • Calculate subnet details from CIDR and classify IPv4 addresses as private or reserved
  • Measure great-circle distance between coordinates and compute Levenshtein edit distance and similarity
  • Count GPT tokens for context budgeting and generate cryptographically random v4 UUIDs
When to use it
Worth adding when an assistant, especially a smaller or local model, gets exact arithmetic, date arithmetic, unit conversion or CIDR math subtly wrong and you want deterministic answers instead of model reasoning.
Requirements
Runs as a local process via npm; needs Node.js v18 or later and an MCP client config pointing at the installed entry point. No API keys, accounts or network access are required.
Before you install
The README describes installing from a cloned repository and running npm install, so review the source and dependencies before running it. All tools are read-only computations; no credentials are requested and no data is sent to third parties.

Installation

In SourceWeft

  1. Open Polymath Megablaster Mcp in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

Polymath MegaBlaster MCP — Deterministic Math, Date, Unit Conversion & Networking Tools for AI Agents

A free, local, 16-tool MCP server that gives AI agents exact, deterministic answers for math, date arithmetic, unit conversion, subnet/networking calculations, statistics, token counting, and real random UUID generation — no network calls, no API keys, no telemetry.

If your AI agent is miscounting days between dates, rounding large numbers incorrectly, getting unit conversions slightly wrong, or messing up subnet/CIDR math, this MCP server exists specifically to fix that class of problem.

The problem this solves

Local and open-weight models (Llama, Qwen, Mistral, etc.) are consistently unreliable at exact math, date arithmetic, unit conversion, and similar deterministic tasks — they "reason" their way to an answer instead of computing it, and get it subtly wrong. (Frontier hosted models like Claude and GPT-4 already handle most of this correctly unaided — this toolkit is aimed at closing the gap for smaller/local models, not replacing what those already do well.) Every tool here uses classical deterministic methods instead of model reasoning, so the answer is always exactly right.

Everyday things it fixes:

  • Exact math on huge numbers, no float rounding errors
  • Correct date math, including leap years and "last day of the month" edge cases
  • Unit conversion (km/miles, °C/°F, kg/lb) without approximation
  • Subnet/CIDR math for networking tasks
  • Great-circle distance between coordinates

More technical tools:

  • Arbitrary-precision arithmetic, factorials, permutations, combinations (no float64 overflow)
  • Statistics (mean, median, stdev, variance, percentiles) on a list of numbers
  • Base conversion (decimal, hex, binary, octal)
  • Levenshtein edit distance and similarity ratio (deterministic fuzzy matching)
  • IANA-aware time zone conversion
  • GPT tokenizer-based token counting, so an agent can manage its own context budget
  • Real cryptographically-random UUID (v4) generation — LLMs reliably fabricate plausible-looking but non-random, potentially colliding UUID strings instead

Why local

Most AI dev tool MCP servers either charge a subscription or call out to a remote API. This one never touches the network. Every tool is pure local computation, verifiable directly in the source: open src/tools.js — there is no fetch or http import anywhere in it.

Setup

1. Install Node.js (v18+) if you don't have it: https://nodejs.org

2. Clone this repo and install dependencies:

bash
git clone https://github.com/headlessherm-creator/polymath-megablaster-mcp.gitcd polymath-megablaster-mcpnpm install

3. Point your MCP client at the local path:

json
{  "mcpServers": {    "polymath": {      "command": "node",      "args": ["/absolute/path/to/polymath-megablaster-mcp/src/index.js"]    }  }}

Add that to your MCP client's config and restart it. Setup docs for common clients:

Tools (16, all free)

  • Deterministic math: calculate (arbitrary-precision expression evaluator), factorial, permutations, combinations (all arbitrary-precision, avoid float64 overflow), compute_statistics (mean, median, stdev, variance, percentiles)
  • Date and time: date_add, date_diff (leap years, month boundaries, business days handled correctly), convert_timezone
  • Conversion: convert_unit (length, weight, volume, temperature), convert_base (decimal, hex, binary, octal)
  • Networking: calc_subnet (CIDR math), check_ip_type (private/reserved range lookup)
  • Text: levenshtein_distance (exact edit distance and similarity ratio)
  • Geo: haversine_distance (exact great-circle distance between coordinates)
  • Agent utility: count_tokens (GPT tokenizer, for managing context budget before a large prompt), generate_uuid (real cryptographically-random v4 UUIDs, 1-100 at a time)

Dependencies

All installed automatically by npm install. None of them make network calls at runtime.

Keywords

deterministic math MCP server, MCP date calculator, MCP unit converter, subnet CIDR calculator MCP, local MCP server no API key, Claude MCP math tools, AI agent exact arithmetic, token counter MCP server.

Related tools

Same local-first philosophy, different problems:

License

MIT

Source: README.md at commit 4e2f25a

Tools

16

calc_subnet

Calculate subnet details (network, broadcast, usable hosts, mask) from a CIDR like 192.168.1.0/24

Parameterscidrrequired

check_ip_type

Check if an IPv4 address is private/reserved and identify which range it falls in

Parametersiprequired

calculate

Evaluate an arbitrary-precision math expression exactly (fixes LLM multi-digit arithmetic errors). Supports +,-,*,/,^,sqrt(),sin(),log(), etc.

Parametersexpressionrequired

count_tokens

Count tokens in text using the GPT-3.5/4 (cl100k_base) tokenizer. Useful for managing context budget before sending a large prompt

Parameterstextrequired

date_add

Add or subtract days/weeks/months/years/businessDays from a date, handling leap years and month boundaries correctly

Parametersdaterequiredunitrequiredamountrequired

date_diff

Compute the exact difference between two dates in days, business days, and hours

Parametersarequiredbrequired

convert_timezone

Convert a UTC/ISO date into a formatted date+time string for any IANA time zone

ParametersdaterequiredtimeZonerequired

compute_statistics

Compute mean, median, stdev, variance, min/max, and percentiles (25/75/90) for a list of numbers

Parametersnumbersrequired

convert_unit

Convert a value between units of length, weight, volume, or temperature (fixes LLM unit-math errors)

ParametersvaluerequiredtoUnitrequiredfromUnitrequired

haversine_distance

Compute exact great-circle distance in km/miles between two lat/long coordinates

Parameterslat1requiredlat2requiredlon1requiredlon2required

factorial

Compute n! exactly using arbitrary-precision integer math (avoids float64 overflow past ~18)

Parametersnrequired

permutations

Compute nPr (permutations) exactly using arbitrary-precision integer math

Parametersnrequiredrrequired

combinations

Compute nCr (combinations) exactly using arbitrary-precision integer math

Parametersnrequiredrrequired

convert_base

Convert a number between decimal, hex, binary, and octal

ParametersvaluerequiredtoBaserequiredfromBaserequired

levenshtein_distance

Compute exact edit distance and similarity ratio between two strings (deterministic fuzzy matching)

Parametersarequiredbrequired

generate_uuid

Generate real cryptographically-random UUIDs (v4). Fixes LLMs fabricating plausible-looking but non-random, potentially colliding UUID strings instead of real random ones.

Parameterscount

Version history

2
  1. v3.1.0LatestOct 22, 2026
  2. v3.0.2Sep 16, 2026

Score

90% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts
  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts