Cruncher
Give your coding agent a safe scientific calculator for stats, trig, and unit conversions without hallucinating numbers.
Overview
Cruncher is a MCP server for the Build phase that gives coding agents 43 schema-validated scientific calculator tools over stdio.
What is this MCP server?
- 43 tools across 8 categories: arithmetic, trigonometry, statistics, and unit conversion
- Exposure tiers via CRUNCHER_TOOL_SET: minimal (5), standard (34, default), or full (43)
- Zero-dependency pure Node.js with worker-thread isolation and configurable CRUNCHER_TIMEOUT
- Strict JSON-Schema validation, MCP 2025-11-25 compliant, tool safety annotations
- Fuzzy tool name matching and LRU result caching for repeated agent calls
- 43 tools across 8 categories in full tier
- Tool tiers: minimal 5, standard 34 (default), full 43
- MCP spec 2025-11-25 compliant; version 1.2.29
What problem does it solve?
Agents often invent or round numbers when you need exact trig, stats, or unit conversions mid-task.
Who is it for?
Indie builders who want dependable math in agent workflows without pasting formulas into chat.
Skip if: Teams that only need occasional arithmetic and are fine with a desktop calculator app.
What do I get? / Deliverables
After you register Cruncher, your agent can call real calculator tools with tiers and timeouts so numeric answers stay auditable.
- Registered stdio MCP server with 5, 34, or 43 calculator tools exposed to the agent
- Validated numeric tool results usable in pricing models, code, and analytics prompts
- Configurable isolation and timeouts for heavier statistical computations
Recommended MCP Servers
Journey fit
Calculator MCPs are wired into the agent stack during build, but builders reuse them whenever the product needs verified math. integrations is the canonical shelf for stdio MCP servers that extend Claude Code, Cursor, or Codex with callable tools.
How it compares
MCP calculator integration with 43 tools, not a spreadsheet skill or Jupyter notebook workflow.
Common Questions / FAQ
Who is Cruncher for?
Cruncher is for solo and indie builders using Claude Code, Cursor, Codex, or similar agents who need verified scientific math during development and analysis.
When should I use Cruncher?
Use it whenever your agent must compute statistics, trig, conversions, or multi-step arithmetic and you want worker-isolated, schema-checked tool calls instead of mental math in the prompt.
How do I add Cruncher to my agent?
Install @slbdn/cruncher-mcp from npm, add the stdio MCP entry in your agent config, and optionally set CRUNCHER_TOOL_SET and CRUNCHER_TIMEOUT for tier size and heavy-calc limits.