Market Data · x402 · early usage

Live snapshot of the most liquid carbon credits retirable on Base: the top 3 Klima Prot…

by x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app · discovered, not yet claimed by its owner · updated 2026-10-10

30d calls4

30d payers4

MethodGET

Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Live snapshot of the most liquid carbon credits retirable on Base: the top 3 Klima Protocol carbon classes and the top 3 Carbonmark marketplace listings, with USDC-per-tonne prices and tonnes available. Additionally, the additional endpoints to quote and retire carbon are included; query those endpoints for further discovery, quotes, and retirements. Query /.well-known, /openapi, and /discover to get started.

Tags: carbon · climate · base · bazaar

Call contract

Method: GET
Input: query parameters
Output: json
Last paid call: 2026-10-10

Input example from Bazaar metadata

{}

Output example

{
  "asOf": "2026-09-15T00:00:00.000Z",
  "classes": [],
  "endpoints": {
    "actionsRetire": "https://x402.klimalabs.com/api/actions/retire",
    "certificate": "https://x402.klimalabs.com/api/certificate",
    "discover": "https://x402.klimalabs.com/api/discover",
    "openapi": "https://x402.klimalabs.com/openapi.json",
    "prepareAuth": "https://x402.klimalabs.com/api/prepare-auth",
    "prepareRetire": "https://x402.klimalabs.com/api/prepare/retire",
    "quote": "https://x402.klimalabs.com/api/quote"
  },
  "listings": [],
  "note": "Prices are USDC per tonne before the on-chain protocol fee. Class prices are indicative live quotes; listing prices are the seller's firm ask. To retire: GET quote, then either GET prepare/retire and send the transactions from your own wallet, or GET prepare-auth, sign its typedData and POST actions/retire. None of those charge an API fee. GET discover returns the full catalog for free."
}

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/36453.json for the price and payment options.
Pay. Call GET https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.001 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base
Demand: 4 calls · 4 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.001	0xf624f9Fe1D3165c5Ca32c7Fbdbf82f4a5b1D2d0e	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xf624f9Fe1D3165c5Ca32c7Fbdbf82f4a5b1D2d0e",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "amountUsd": 0.001,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)

{
  "properties": {
    "example": {
      "additionalProperties": false,
      "properties": {
        "asOf": {
          "type": "string"
        },
        "classes": {
          "items": {
            "additionalProperties": false,
            "properties": {
              "carbonClassId": {
                "type": "string"
              },
              "category": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "country": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "creditCount": {
                "type": "number"
              },
              "liquidityTonnes": {
                "type": "string"
              },
              "name": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "priceBasis": {
                "const": "indicative",
                "type": "string"
              },
              "priceUsdcPerTonne": {
                "type": "string"
              },
              "priceUsdcPerTonneFormatted": {
                "type": "string"
              }
            },
            "required": [
              "carbonClassId",
              "name",
              "category",
              "country",
              "priceUsdcPerTonne",
              "priceUsdcPerTonneFormatted",
              "priceBasis",
              "liquidityTonnes",
              "creditCount"
            ],
            "type": "object"
          },
          "type": "array"
        },
        "endpoints": {
          "additionalProperties": false,
          "properties": {
            "actionsRetire": {
              "type": "string"
            },
            "certificate": {
              "type": "string"
            },
            "discover": {
              "type": "string"
            },
            "openapi": {
              "type": "string"
            },
            "prepareAuth": {
              "type": "string"
            },
            "prepareRetire": {
              "type": "string"
            },
            "quote": {
              "type": "string"
            }
          },
          "required": [
            "discover",
            "quote",
            "prepareRetire",
            "prepareAuth",
            "actionsRetire",
            "certificate",
            "openapi"
          ],
          "type": "object"
        },
        "listings": {
          "items": {
            "additionalProperties": false,
            "properties": {
              "category": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "country": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "creditId": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "expiresAt": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "leftToSellTonnes": {
                "type": "string"
              },
              "listingId": {
                "type": "string"
              },
              "minFillTonnes": {
                "type": "string"
              },
              "priceBasis": {
                "const": "firm",
                "type": "string"
              },
              "priceUsdcPerTonne": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "priceUsdcPerTonneFormatted": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "projectName": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "registry": {
                "anyOf": [
                  {
                    "type": "string"
                  },
                  {
                    "type": "null"
                  }
                ]
              },
              "vintage": {
                "anyOf": [
                  {
                    "type": "number"
                  },
                  {
                    "type": "null"
                  }
                ]
              }
            },
            "required": [
              "listingId",
              "projectName",
              "creditId",
              "registry",
              "vintage",
              "country",
              "category",
              "priceUsdcPerTonne",
              "priceUsdcPerTonneFormatted",
              "priceBasis",
              "leftToSellTonnes",
              "minFillTonnes",
              "expiresAt"
            ],
            "type": "object"
          },
          "type": "array"
        },
        "note": {
          "type": "string"
        }
      },
      "required": [
        "asOf",
        "classes",
        "listings",
        "endpoints",
        "note"
      ],
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}

Example shape — generated from the schema, not a captured live response

{
  "example": {
    "asOf": "string",
    "classes": [
      {
        "carbonClassId": "string",
        "category": null,
        "country": null,
        "creditCount": 0,
        "liquidityTonnes": "string",
        "name": null,
        "priceBasis": "string",
        "priceUsdcPerTonne": "string",
        "priceUsdcPerTonneFormatted": "string"
      }
    ],
    "endpoints": {
      "actionsRetire": "string",
      "certificate": "string",
      "discover": "string",
      "openapi": "string",
      "prepareAuth": "string",
      "prepareRetire": "string",
      "quote": "string"
    },
    "listings": [
      {
        "category": null,
        "country": null,
        "creditId": null,
        "expiresAt": null,
        "leftToSellTonnes": "string",
        "listingId": "string",
        "minFillTonnes": "string",
        "priceBasis": "string",
        "priceUsdcPerTonne": null,
        "priceUsdcPerTonneFormatted": null,
        "projectName": null,
        "registry": null,
        "vintage": null
      }
    ],
    "note": "string"
  },
  "type": "string"
}

Examples

curl

curl -X GET 'https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog", {
  "method": "GET"
});
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.request("GET", "https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app
Endpoint: https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog
Machine-readable: /resources/36453.json