FETCH402
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Resource / 257

healthy

WebberSites x402 Data API.

GET https://api.webbersites.com/api/calc ↗

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.

Eligibility
probeable
Failures
0
Last quote
2026-08-12 22:00:02 UTC
Last probe
2026-08-12 22:00:02 UTC
Payment requirements / accepts[] 1 options
State Network Scheme Atomic amount Asset payTo / untrusted
active eip155:8453 exact 1000 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 0xdd5fcEa81CA6f1EB39FEd5B973DE794293B81ba6

All advertised payment options are stored. Base (`eip155:8453`) is the operational network for ranking and canaries; non-Base options remain visible for transparency.

Probe evidence 1 recent
healthy 2026-08-12 22:00:02 UTC GET · HTTP 402 · 29ms · accepts 1 · base 1 ok
Request
GET https://api.webbersites.com/api/calc
Robots
error
Note
robots_error:{:robots_http_status, 404};http_402;accepts=1;base=1
Accepts fingerprint
762a8ed43e08d5daa643a2efb9cabaea37e5ccb22871d8f900a7880c697542f6

Accepts snapshot

[
  {
    "amount": "1000",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "assetTransferMethod": null,
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "maxTimeoutSeconds": 300,
    "network": "eip155:8453",
    "payTo": "0xdd5fcEa81CA6f1EB39FEd5B973DE794293B81ba6",
    "paymentFlow": null,
    "raw": {
      "amount": "1000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "maxTimeoutSeconds": 300,
      "max_timeout_seconds": 300,
      "network": "eip155:8453",
      "payTo": "0xdd5fcEa81CA6f1EB39FEd5B973DE794293B81ba6",
      "pay_to": "0xdd5fcEa81CA6f1EB39FEd5B973DE794293B81ba6",
      "scheme": "exact"
    },
    "scheme": "exact"
  }
]

PaymentRequired raw 

{
  "accepts": [
    {
      "amount": "1000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "maxTimeoutSeconds": 300,
      "network": "eip155:8453",
      "payTo": "0xdd5fcEa81CA6f1EB39FEd5B973DE794293B81ba6",
      "scheme": "exact"
    }
  ],
  "error": "Payment required",
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "method": "GET",
          "queryParams": {
            "expr": "8347293847 * 9928374652"
          },
          "type": "http"
        },
        "output": {
          "example": {
            "expr": "8347293847 * 9928374652",
            "precision": "50 significant digits",
            "result": "82875060643350366244",
            "type": "BigNumber"
          },
          "type": "json"
        }
      },
      "schema": {
        "$schema": "https://json-schema.org/draft/2020-12/schema",
        "properties": {
          "input": {
            "additionalProperties": false,
            "properties": {
              "method": {
                "enum": [
                  "GET"
                ],
                "type": "string"
              },
              "queryParams": {
                "properties": {
                  "expr": {
                    "description": "Math expression, max 400 chars — e.g. '2^128', 'sqrt(2)', '12 inch to cm'",
                    "type": "string"
                  }
                },
                "required": [
                  "expr"
                ],
                "type": "object"
              },
              "type": {
                "const": "http",
                "type": "string"
              }
            },
            "required": [
              "type",
              "method"
            ],
            "type": "object"
          },
          "output": {
            "properties": {
              "example": {
                "properties": {
                  "expr": {
                    "type": "string"
                  },
                  "result": {
                    "description": "exact result as a string",
                    "type": "string"
                  },
                  "result_number": {
                    "description": "float64 companion when finite",
                    "type": "number"
                  },
                  "type": {
                    "type": "string"
                  }
                },
                "type": "object"
              },
              "type": {
                "type": "string"
              }
            },
            "required": [
              "type"
            ],
            "type": "object"
          }
        },
        "required": [
          "input"
        ],
        "type": "object"
      }
    }
  },
  "resource": {
    "description": "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.",
    "iconUrl": "https://x402.webbersites.com/webbersites-icon.png",
    "mimeType": "application/json",
    "serviceName": "WebberSites x402 Data API",
    "tags": [
      "Math"
    ],
    "url": "https://api.webbersites.com/api/calc"
  },
  "x402Version": 2
}

Response headers

{
  "access-control-allow-origin": "*",
  "access-control-expose-headers": "Payment-Required, X-Payment-Response, Payment-Response, Link, WWW-Authenticate",
  "alt-svc": "h3=\":443\"; ma=86400",
  "cf-cache-status": "DYNAMIC",
  "cf-ray": "a2a2c0278d54744b-IAD",
  "connection": "keep-alive",
  "content-type": "application/json; charset=utf-8",
  "date": "Wed, 12 Aug 2026 22:00:02 GMT",
  "etag": "W/\"1dd-DK0CgsFtlXZKl40rAbPX8Mfno6Q\"",
  "link": "<https://api.webbersites.com/openapi.json>; rel=\"service-desc\"; type=\"application/json\", <https://api.webbersites.com/.well-known/x402>; rel=\"payment-method\"; type=\"application/json\", <https://api.webbersites.com/.well-known/l402.json>; rel=\"payment-method\"; type=\"application/json\", <https://api.webbersites.com/.well-known/mpp.json>; rel=\"payment-method\"; type=\"application/json\", <https://x402.webbersites.com/docs/>; rel=\"service-doc\"; type=\"text/html\"",
  "payment-required": "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",
  "rndr-id": "2379469b-f505-447b",
  "server": "cloudflare",
  "transfer-encoding": "chunked",
  "vary": "Accept-Encoding",
  "www-authenticate": "Payment id=\"aTLhiSKxrK6WKthMxGCqyPvH1svQ3ySgpnqV7X2Y-BI\", realm=\"x402-data-api.onrender.com\", method=\"evm\", intent=\"charge\", request=\"eyJhbW91bnQiOiIxMDAwIiwiY3VycmVuY3kiOiIweDgzMzU4OWZDRDZlRGI2RTA4ZjRjN0MzMkQ0ZjcxYjU0YmRBMDI5MTMiLCJtZXRob2REZXRhaWxzIjp7ImNoYWluSWQiOjg0NTMsImNyZWRlbnRpYWxUeXBlcyI6WyJhdXRob3JpemF0aW9uIl0sImRlY2ltYWxzIjo2fSwicmVjaXBpZW50IjoiMHhkZDVmY0VhODFDQTZmMUVCMzlGRWQ1Qjk3M0RFNzk0MjkzQjgxYmE2In0\", description=\"WebberSites API /api/calc\", expires=\"2026-08-12T22:05:02.503Z\"",
  "x-powered-by": "Express",
  "x-render-origin-server": "Render"
}

Response body 

{
  "agent_tip": "One call, finished deliverables: GET /api/seo/full-audit runs 7 analyses with a 0-100 score for $0.02; /api/seo/site-audit covers up to 8 pages for $0.05; POST /api/brand/kit returns logo + app icon + social card + palette for $0.05; POST /api/website/build ships up to 6 consistent HTML pages for $0.05.",
  "reward": "Bought anything over $0.001 in the last 24 hours? Add header X-Wallet: 0xYourAddress (or ?wallet=) and this call costs $0.0005 instead of $0.001."
}

Request headers

{
  "accept": "*/*",
  "user-agent": "Fetch402Bot/0.1 (+https://fetch402.com/crawler; contact: crawler@fetch402.com)"
}

Machine contract

Schemas.

InputJSON
{
  "method": "GET",
  "queryParams": {
    "expr": "8347293847 * 9928374652"
  },
  "type": "http"
}
OutputJSON
{
  "example": {
    "expr": "8347293847 * 9928374652",
    "precision": "50 significant digits",
    "result": "82875060643350366244",
    "type": "BigNumber"
  },
  "type": "json"
}