Entry point to the x402 carbon retirement API on Base
Entry point to the x402 carbon retirement API on Base. Returns every endpoint you need (free discover, quote and certificate; prepare-auth + POST actions/retire to retire with a signed USDC authorization) plus a live snapshot of the top 3 carbon classes and marketplace listings by liquidity. Start with /api/discover and /api/quote; full spec at /openapi.json.
1000 (raw units)
price
2
calls / 30d
2
unique payers
2026-09-17
updated
Provider
x402.klimalabs.com · discovered, not yet claimed by its owner
Payment (x402 accepts[])
[
{
"scheme": "exact",
"network": "eip155:8453",
"payTo": "0xf624f9Fe1D3165c5Ca32c7Fbdbf82f4a5b1D2d0e",
"asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
"amount": "1000",
"maxTimeoutSeconds": 300
}
]Output schema
{
"bazaar": {
"info": {
"input": {
"method": "GET",
"queryParams": {},
"type": "http"
},
"output": {
"example": {
"asOf": "2026-09-15T00:00:00.000Z",
"catalogNote": "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.",
"classes": [],
"endpoints": {
"actionsRetire": {
"method": "POST",
"url": "https://x402.klimalabs.com/api/actions/retire"
},
"certificate": {
"method": "GET",
"url": "https://x402.klimalabs.com/api/certificate"
},
"discover": {
"method": "GET",
"url": "https://x402.klimalabs.com/api/discover"
},
"manifest": {
"method": "GET",
"url": "https://x402.klimalabs.com/.well-known/x402.json"
},
"note": "Start here: every carbon retirement goes through these endpoints. discover, quote, prepare/retire, prepare-auth and certificate are free to call. Retiring pays the credit price plus the on-chain protocol fee (and executor gas when relayed through actions/retire), funded by your wallet or signed authorization. Full request and response schemas: https://x402.klimalabs.com/openapi.json",
"openapi": {
"method": "GET",
"url": "https://x402.klimalabs.com/openapi.json"
},
"prepareAuth": {
"method": "GET",
"url": "https://x402.klimalabs.com/api/prepare-auth"
},
"prepareRetire": {
"method": "GET",
"url": "https://x402.klimalabs.com/api/prepare/retire"
},
"quote": {
"method": "GET",
"url": "https://x402.klimalabs.com/api/quote"
}
},
"listings": []
},
"type": "json"
}
},
"schema": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"additionalProperties": false,
"properties": {},
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"additionalProperties": false,
"properties": {
"asOf": {
"type": "string"
},
"catalogNote": {
"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": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"certificate": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"discover": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"manifest": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"note": {
"type": "string"
},
"openapi": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"prepareAuth": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"prepareRetire": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
},
"quote": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"POST"
],
"type": "string"
},
"url": {
"type": "string"
}
},
"required": [
"url",
"method"
],
"type": "object"
}
},
"required": [
"note",
"discover",
"quote",
"prepareRetire",
"prepareAuth",
"actionsRetire",
"certificate",
"openapi",
"manifest"
],
"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"
}
},
"required": [
"asOf",
"endpoints",
"classes",
"listings",
"catalogNote"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}
}
}Use it
curl
curl "https://x402.klimalabs.com/api/catalog" # -> 402 Payment Required, accepts[] lists how to pay # retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://x402.klimalabs.com/api/catalog");
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.get("https://x402.klimalabs.com/api/catalog")
if res.status_code == 402:
accepts = res.json()["accepts"]
# pay one of accepts[] via an x402 client, then retry with the payment headerMachine-readable
Everything on this page is also available as clean JSON at /resources/7711.json, and this resource appears in /discovery/resources and /discovery/search.