# webbersites.com Exact-Precision Calculator

> webbersites.com Exact-Precision Calculator is a paid API for AI agents from api.webbersites.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-10).

Evaluates a math expression at 50-significant-digit BigNumber precision and returns the exact result as a string

## Facts

- Endpoint: GET https://api.webbersites.com/api/calc?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/webbersites-com-exact-precision-calculator-d6a660ba
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Zsas72AsComY5LkoBOy5e

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability webbersites-com-exact-precision-calculator-d6a660ba
```

Example prompt: What is 2^128 exactly? Use the high-precision calculator — I need the full integer result, not a rounded float.

## When to prefer this

Use this endpoint whenever exact arithmetic is required and LLM-native computation is unreliable — particularly for large integer multiplication, high-precision division, roots or logarithms, factorials of large numbers, or unit conversions. Prefer this over asking an LLM to compute math directly, since LLMs are known to produce plausible but incorrect results for non-trivial arithmetic. This is deterministic and never executes arbitrary code.

## Known failure modes

- Expression exceeds 400 characters — truncate or simplify the input
- Unsupported mathematical function or syntax returns an error or null result
- Division by zero returns an error response
- Malformed expression string causes a parse error
- Unit conversion with unrecognized units returns an error

## How this service works

Exact math for agents — the arithmetic LLMs get plausibly wrong. Evaluates an expression at 50-significant-digit precision (BigNumber): big-integer multiplication, high-precision division, roots, logs, factorials, unit conversions (12 inch to cm). GET ?expr=…, result returned as an exact string. Deterministic, no AI, never executed as code.

## Output

A JSON object containing the original expression, the type of result, an exact string representation of the answer at up to 50-significant-digit BigNumber precision, and an optional float64 companion value when the result is finite.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "expr"
     ],
     "properties": {
      "expr": {
       "type": "string",
       "description": "Math expression, max 400 chars — e.g. '2^128', 'sqrt(2)', '12 inch to cm'"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "expr": {
       "type": "string"
      },
      "type": {
       "type": "string"
      },
      "result": {
       "type": "string",
       "description": "exact result as a string"
      },
      "result_number": {
       "type": "number",
       "description": "float64 companion when finite"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "expr": "8347293847 * 9928374652",
  "type": "BigNumber",
  "result": "82875060643350366244",
  "precision": "50 significant digits"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/webbersites-com-exact-precision-calculator-d6a660ba/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.webbersites.com](https://www.zero.xyz/host/api.webbersites.com/llms.txt)