headlessherm-creator/polymath-megablaster-mcp

Local and open-weight models (Llama, Qwen, Mistral, etc.) are consistently bad at exact math, date arithmetic, unit conversion, and a dozen other deterministic tasks. (Frontier hosted models like Claude and GPT-4 handle most of this correctly unaided already — this tool is aimed at closing the gap for smaller/local models, not replacing what those already do well.)
This is a local toolkit of 15 free tools that give AI agents a way to offload the kinds of computations reasoning models generally do not perform very well, computations are offloaded onto a calculator that uses classical deterministic methods to ascertain needed values. Fully offline, deterministic and 100% local, no network calls, no telemetry, no API keys. Fully open source and built lean.
**Useful things it does:**
- Does exact math on huge numbers without rounding errors
- Figures out dates correctly, including leap years and "the last day of the month" edge cases
- Converts between units (km/miles, C/F, kg/lb) without approximating
- Works out subnet math for networking
- Computes distance between two coordinates (great-circle)
**More technical things it does:**
- Arbitrary-precision arithmetic, factorials, permutations, combinations (avoids 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)
- Time zone conversion (IANA zone aware)
- Token counting (GPT tokenizer) so an agent can manage its own context budget
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 in the source: read src/tools.js, there is no fetch or http import anywhere in it.
Setup
**1. Install Node.js** (v18 or newer) if you don't have it: https://nodejs.org
**2. Clone this repo and install dependencies:**
**3. Point your MCP client at the local path:**
Add that to your MCP client's config and restart it. Setup docs for common clients:
- Claude Desktop: https://modelcontextprotocol.io/quickstart/user
- Cursor: https://docs.cursor.com/context/model-context-protocol
- Claude Code: https://docs.claude.com/en/docs/claude-code/mcp
Tools (15, 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)