# 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](https://arithym.xyz)** · **[Documentation](https://arithym.xyz/docs.html)** · **[Research Paper](https://arithym.xyz/research.pdf)**

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

Get your API key at [arithym.xyz](https://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
```

---

## 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" }
```

---

## 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](mailto:jacob@arithym.xyz) |

All tiers access all 203 methods. Sign up at [arithym.xyz](https://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](https://arithym.xyz/legal/privacy.html) · [Terms of Service](https://arithym.xyz/legal/terms.html)

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## Support

**Email:** [jacob@arithym.xyz](mailto:jacob@arithym.xyz) · **Docs:** [arithym.xyz/docs.html](https://arithym.xyz/docs.html) · **Research:** [arithym.xyz/research.pdf](https://arithym.xyz/research.pdf)

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