One endpoint for everything (OpenRouter-style): describe what you need and pass the input;

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x318d34fa0bd69eff17fac648d2df8cf7a88b3dbe",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "20000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "input": {
            "amount": 100,
            "base": "USD",
            "quote": "MXN"
          },
          "need": "convert 100 US dollars to Mexican pesos"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "example": {
          "executed": true,
          "result": {
            "converted": 1842
          },
          "tool": {
            "name": "fx_rate",
            "price": "$0.001"
          }
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "body": {
              "additionalProperties": false,
              "properties": {
                "input": {
                  "additionalProperties": true,
                  "description": "Input for the chosen tool (must match its schema)",
                  "type": "object"
                },
                "maxPriceUsd": {
                  "default": 0.01,
                  "description": "Do not execute tools priced above this; return the match instead",
                  "maximum": 1,
                  "minimum": 0,
                  "type": "number"
                },
                "need": {
                  "description": "What you need, in plain language",
                  "maxLength": 500,
                  "minLength": 3,
                  "type": "string"
                },
                "tool": {
                  "description": "Force a specific tool id (skip routing)",
                  "type": "string"
                }
              },
              "required": [
                "need",
                "input"
              ],
              "type": "object"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://toll402.dev/v1/do"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://toll402.dev/v1/do");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://toll402.dev/v1/do")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header