Arithym — Precision Math Engine for AI Agents

Exact arithmetic, tolerance-tracked results, zero hallucination. One MCP connection gives your AI agent 203 precision math methods across 22 domains.

Website · Documentation · Research Paper

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What is Arithym?

Arithym is a computation layer that eliminates math errors in AI agents. Instead of letting your LLM guess at arithmetic, Arithym handles every calculation with exact fraction math — no floating point, no silent rounding, no accumulated drift.

Every approximate result carries exact tolerance bounds so your agent knows not just the answer, but how precise it is.

Works with Claude, ChatGPT, Cursor, Windsurf, and any MCP client.

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Connect in Seconds

Claude or ChatGPT (OAuth — easiest)

1. Go to Settings → Connectors (Claude) or Settings → Apps (ChatGPT)
2. Add custom connector: https://arithym.xyz/mcp
3. Enter your email on the authorize page
4. Connected — no API key, no config files

Claude Desktop (API Key)

Edit claude_desktop_config.json:

{
  "mcpServers": {
    "arithym": {
      "url": "https://arithym.xyz/sse",
      "headers": {
        "Authorization": "Bearer YOUR_API_KEY"
      }
    }
  }
}

Get your API key at arithym.xyz → click Start → enter email → verify.

Cursor / Windsurf / Other MCP Clients

Server URL:  https://arithym.xyz/sse
Transport:   SSE
Header:      Authorization: Bearer YOUR_API_KEY

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Examples

1. Exact Arithmetic

compute("12847", "93", "multiply")
→ { "answer": "1194771", "exact": true }

2. The Classic Float Test

fraction_math("0.1", "0.2", "add")
→ { "answer": "0.3", "exact": true }

Python returns 0.30000000000000004. Arithym returns 0.3.

3. Multi-Step Calculation

scratch_math([
  {"values": ["99.95", "1.0825"], "read": "multiply", "label": "with_tax"},
  {"values": ["$with_tax", "3"], "read": "multiply", "label": "total"},
  {"values": ["$total", "20.50"], "read": "subtract"}
])
→ { "answer": "304.087625", "exact": true }

4. Tolerance Propagation (Measurements)

field_create()
field_add("length", "9.81", sig_figs="3")     → ±0.005
field_add("width", "20.5", sig_figs="3")      → ±0.05
field_derive("length, width", "multiply", "area")
→ { "value": "201.105", "tolerance": "±593/1000" }

5. Compute Graphs with Sensitivity

graph_define({
  "name": "pricing",
  "inputs": {"units": {"value": "1000"}, "cost": {"value": "45"}, "margin": {"value": "1/4"}},
  "graph": [
    {"name": "base", "op": "multiply", "from": ["units", "cost"]},
    {"name": "markup", "op": "multiply", "from": ["base", "margin"]},
    {"name": "revenue", "op": "add", "from": ["base", "markup"]}
  ],
  "outputs": ["revenue"]
})
graph_sensitivity("units") → { "revenue": "225/4" }
graph_solve("units", "revenue", "100000") → { "solution": "1778" }

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Capabilities

203 methods across 22 domains: Arithmetic, Trigonometry, Calculus, Finance, Matrix, Statistics, Chemistry, Physics, Units, Geometry, Signals, Complex Numbers, Number Theory, Algebra, Materials, Medical, Quantum, and more.

Call help() for the full system overview. Call discover("keyword") to search all 203 methods.

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Pricing

Tier	Daily Limit	Price
Explorer	50 computations	Free
Pro	500 computations	$5/mo
Engineer	2,000 computations	$20/mo
Enterprise	Custom	Contact

All tiers access all 203 methods. Sign up at arithym.xyz.

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Authentication

• OAuth 2.1 — For Claude and ChatGPT Connectors. Zero-config, PKCE-secured.
• API Key — For Claude Desktop, Cursor, and other MCP clients. Bearer token.

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Privacy & Security

• Does not log, store, or retain computational inputs or outputs
• API keys stored as SHA-256 hashes
• SSL/TLS encryption for all data in transit
• Privacy Policy · Terms of Service

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Support

Email: jacob@arithym.xyz · Docs: arithym.xyz/docs.html · Research: arithym.xyz/research.pdf

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