x402-unit-convert

Live 402 challenge

Captured by the enrichment pass, not read just now. Prices can change — always read the 402 the endpoint answers with.

{
  "error": "payment_required",
  "accepts": [
    {
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "extra": {
        "name": "USD Coin",
        "version": "2"
      },
      "payTo": "0x6f60659390aDA1D02B14024d8c9d0C889f2F89c3",
      "scheme": "exact",
      "network": "base",
      "mimeType": "application/json",
      "resource": "https://x402-catalog-history.ai-business-surface.workers.dev/convert",
      "description": "Unit conversion in one GET, without an LLM or a calculator: length, mass, volume, data and time, plus temperature. curl: GET /convert?value=1&from=km&to=m (from/to are unit names; temperature uses c|f|k). Response: {\"input\":{\"value\":1,\"from\":\"km\",\"to\":\"m\"},\"category\":\"length\",\"result\":1000,\"unit\":\"m\",\"formula\":\"1 km = 1000 m\"}. The definitions are fixed in this Worker; no external service is called. Unknown units and cross-category pairs are refused with 400 before payment. 0.001 USDC, no account, no key, one GET, one delivery. A purchase is two calls by design: this first call returns 402 with the price and the payment terms, and you then repeat the same request with the PAYMENT-SIGNATURE header to receive the 200 delivery.",
      "maxAmountRequired": "1000",
      "maxTimeoutSeconds": 60
    }
  ],
  "receive": {
    "note": "One payment buys one delivery. The amount in this 402 is the current price; nothing is paid until you sign.",
    "step_1": "pay accepts[0] (0.001 USDC on Base, eip155:8453) with any x402 client; the client keeps the transaction hash",
    "step_2": "send the same request again with the PAYMENT-SIGNATURE header — the 200 body that comes back is the delivery, and it carries your tx and payer under delivery.payment so you can match it on chain. An x402 client library does this second call for you.",
    "free_preview": null,
    "what_you_get": "one delivery of /convert: the 200 response body, returned by the request that carries your payment (nothing is delivered by the 402 itself)",
    "free_catalogue": "https://x402-catalog-history.ai-business-surface.workers.dev/",
    "free_preview_note": "This route has no separate free sample; the catalogue at / states its exact input, output and price before you pay.",
    "if_you_do_not_resend": {
      "credit": "POST https://x402-catalog-history.ai-business-surface.workers.dev/credit/claim with {\"tx\":\"0x<your tx hash>\"} — the transfer is read on Base. Exactly 0.01 USDC comes back as the /digest delivery itself (one call, no credit id). Other amounts from 0.01 USDC return a credit id (5 USDC or more issues the 110-call pack). Then send X-CREDIT: <credit_id> on this route and the 200 body is the delivery — no 402 body and no second payment needed.",
      "human_route": "https://x402-catalog-history.ai-business-surface.workers.dev/preflight/buy and https://x402-catalog-history.ai-business-surface.workers.dev/ja/services are the operator's human-facing pages: the same measurements can be bought with a plain USDC transfer and a claim, with no x402 client at all.",
      "delivery_record": "https://x402-catalog-history.ai-business-surface.workers.dev/delivery-receipt?format=json (free) explains the record that matches one settled payment to one delivery, and the track record on https://x402-catalog-history.ai-business-surface.workers.dev/ (free) lists the totals (orders, amount, per product) of the deliveries this service recorded, and no buyer identifier is published — so a settled payment can be checked against a delivery by tx or payer instead of by guessing from the clock."
    },
    "pay_less_or_fixed_amount": {
      "note": "if you pay a fixed amount and do not read this body, use the cheapest route above and send the same request again with your payment: the 200 body is the delivery and it carries your tx and payer under delivery.payment",
      "cheapest_route": {
        "path": "/gas",
        "method": "GET",
        "price_usd": 0.001,
        "price_atomic": "1000"
      },
      "this_route_costs_usd": 0.001,
      "this_route_costs_atomic": "1000",
      "accept_less_is_not_possible": "the facilitator settles exactly one amount per payment and this Worker verifies it against this route's price, so a smaller transfer cannot buy this route",
      "routes_at_or_below_this_price": [
        {
          "path": "/gas",
          "method": "GET",
          "price_usd": 0.001,
          "price_atomic": "1000",
          "free_of_extra_parameters": false
        },
        {
          "path": "/random",
          "method": "GET",
          "price_usd": 0.001,
          "price_atomic": "1000",
          "free_of_extra_parameters": true
        },
        {
          "path": "/convert",
          "method": "GET",
          "price_usd": 0.001,
          "price_atomic": "1000",
          "free_of_extra_parameters": false
        },
        {
          "path": "/ts",
          "method": "GET",
          "price_usd": 0.001,
          "price_atomic": "1000",
          "free_of_extra_parameters": false
        }
      ]
    }
  },
  "resource": {
    "url": "https://x402-catalog-history.ai-business-surface.workers.dev/convert",
    "tags": [
      "unit-conversion",
      "convert",
      "measurement",
      "temperature",
      "calculator"
    ],
    "mimeType": "application/json",
    "description": "Unit conversion in one GET, without an LLM or a calculator: length, mass, volume, data and time, plus temperature. curl: GET /convert?value=1&from=km&to=m (from/to are unit names; temperature uses c|f|k). Response: {\"input\":{\"value\":1,\"from\":\"km\",\"to\":\"m\"},\"category\":\"length\",\"result\":1000,\"unit\":\"m\",\"formula\":\"1 km = 1000 m\"}. The definitions are fixed in this Worker; no external service is called. Unknown units and cross-category pairs are refused with 400 before payment. 0.001 USDC, no account, no key, one GET, one delivery. A purchase is two calls by design: this first call returns 402 with the price and the payment terms, and you then repeat the same request with the PAYMENT-SIGNATURE header to receive the 200 delivery.",
    "serviceName": "x402-unit-convert"
  },
  "extensions": {
    "bazaar": {
      "info": {
        "input": {
          "type": "http",
          "method": "GET",
          "queryParams": {
            "to": "m",
            "from": "km",
            "value": "1"
          }
        },
        "output": {
          "type": "json",
          "example": {
            "unit": "m",
            "input": {
              "to": "m",
              "from": "km",
              "value": 1
            },
            "result": 1000,
            "source": "fixed unit definitions in this Worker",
            "formula": "1 km = 1000 m",
            "category": "length",
            "product_id": "x402-unit-convert",
            "converted_at": "2026-10-18T00:00:00.000Z",
            "schema_version": 1
          }
        }
      },
      "schema": {
        "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",
                  "HEAD",
                  "DELETE"
                ],
                "type": "string"
              },
              "queryParams": {
                "type": "object",
                "properties": {
                  "to": {
                    "type": "string"
                  },
                  "from": {
                    "type": "string"
                  },
                  "value": {
                    "type": "string"
                  }
                }
              }
            },
            "additionalProperties": false
          },
          "output": {
            "type": "object",
            "required": [
              "type"
            ],
            "properties": {
              "type": {
                "type": "string"
              },
              "example": {
                "type": "object"
              }
            }
          }
        }
      }
    }
  },
  "x402Version": 1,
  "payment_required_v2": {
    "error": "payment_required",
    "accepts": [
      {
        "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        "extra": {
          "name": "USD Coin",
          "version": "2"
        },
        "payTo": "0x6f60659390aDA1D02B14024d8c9d0C889f2F89c3",
        "amount": "1000",
        "scheme": "exact",
        "network": "eip155:8453",
        "maxTimeoutSeconds": 60
      }
    ],
    "resource": {
      "url": "https://x402-catalog-history.ai-business-surface.workers.dev/convert",
      "tags": [
        "unit-conversion",
        "convert",
        "measurement",
        "temperature",
        "calculator"
      ],
      "mimeType": "application/json",
      "description": "Unit conversion in one GET, without an LLM or a calculator: length, mass, volume, data and time, plus temperature. curl: GET /convert?value=1&from=km&to=m (from/to are unit names; temperature uses c|f|k). Response: {\"input\":{\"value\":1,\"from\":\"km\",\"to\":\"m\"},\"category\":\"length\",\"result\":1000,\"unit\":\"m\",\"formula\":\"1 km = 1000 m\"}. The definitions are fixed in this Worker; no external service is called. Unknown units and cross-category pairs are refused with 400 before payment. 0.001 USDC, no account, no key, one GET, one delivery. A purchase is two calls by design: this first call returns 402 with the price and the payment terms, and you then repeat the same request with the PAYMENT-SIGNATURE header to receive the 200 delivery.",
      "serviceName": "x402-unit-convert"
    },
    "extensions": {
      "bazaar": {
        "info": {
          "input": {
            "type": "http",
            "method": "GET",
            "queryParams": {
              "to": "m",
              "from": "km",
              "value": "1"
            }
          },
          "output": {
            "type": "json",
            "example": {
              "unit": "m",
              "input": {
                "to": "m",
                "from": "km",
                "value": 1
              },
              "result": 1000,
              "source": "fixed unit definitions in this Worker",
              "formula": "1 km = 1000 m",
              "category": "length",
              "product_id": "x402-unit-convert",
              "converted_at": "2026-10-18T00:00:00.000Z",
              "schema_version": 1
            }
          }
        },
        "schema": {
          "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",
                    "HEAD",
                    "DELETE"
                  ],
                  "type": "string"
                },
                "queryParams": {
                  "type": "object",
                  "properties": {
                    "to": {
                      "type": "string"
                    },
                    "from": {
                      "type": "string"
                    },
                    "value": {
                      "type": "string"
                    }
                  }
                }
              },
              "additionalProperties": false
            },
            "output": {
              "type": "object",
              "required": [
                "type"
              ],
              "properties": {
                "type": {
                  "type": "string"
                },
                "example": {
                  "type": "object"
                }
              }
            }
          }
        }
      }
    },
    "x402Version": 2
  }
}

Accepts

The payment requirements as published to the catalog. Read the live 402 before paying — a price here is a claim, not a quote.

[
  {
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "extra": {
      "name": "USD Coin",
      "version": "2"
    },
    "payTo": "0x6f60659390aDA1D02B14024d8c9d0C889f2F89c3",
    "amount": "1000",
    "scheme": "exact",
    "network": "eip155:8453",
    "maxTimeoutSeconds": 60
  }
]

Extensions

{
  "bazaar": {
    "info": {
      "input": {
        "type": "http",
        "method": "GET",
        "queryParams": {
          "to": "m",
          "from": "km",
          "value": "1"
        }
      },
      "output": {
        "type": "json",
        "example": {
          "unit": "m",
          "input": {
            "to": "m",
            "from": "km",
            "value": 1
          },
          "result": 1000,
          "source": "fixed unit definitions in this Worker",
          "formula": "1 km = 1000 m",
          "category": "length",
          "product_id": "x402-unit-convert",
          "converted_at": "2026-10-18T00:00:00.000Z",
          "schema_version": 1
        }
      }
    },
    "schema": {
      "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",
                "HEAD",
                "DELETE"
              ],
              "type": "string"
            },
            "queryParams": {
              "type": "object",
              "properties": {
                "to": {
                  "type": "string"
                },
                "from": {
                  "type": "string"
                },
                "value": {
                  "type": "string"
                }
              }
            }
          },
          "additionalProperties": false
        },
        "output": {
          "type": "object",
          "required": [
            "type"
          ],
          "properties": {
            "type": {
              "type": "string"
            },
            "example": {
              "type": "object"
            }
          }
        }
      }
    }
  }
}

Provenance

Seen in the source catalog

2026-10-17 17:20Z

Last indexed by Roundhouse

2026-10-26 13:46Z

Last enriched (probe, favicon, geo)

2026-10-18 01:45Z

x402 version

2

Max timeout

60s

Liveness probe

HTTP 402