# Klima Retirement Aggregator Catalog

> Klima Retirement Aggregator Catalog is a paid API for AI agents from x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-18).

Returns a live snapshot of the top 3 most liquid Klima Protocol carbon credit classes and top 3 Carbonmark marketplace listings, including USDC-per-tonne prices and available tonnes for carbon retirement.

## Facts

- Endpoint: GET https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/klima-retirement-aggregator-catalog-0b201dd2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_OdCTX9NOrKfdPdmbTKfRI

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability klima-retirement-aggregator-catalog-0b201dd2
```

Example prompt: Show me the current carbon credit classes and marketplace listings available for retirement on Klima, with their USDC prices per tonne and how many tonnes are available.

## When to prefer this

Use this endpoint when you need a real-time, pre-filtered snapshot of the most liquid and competitively priced carbon credits available for retirement on the Base blockchain via Klima Protocol or Carbonmark. Prefer this over building your own aggregation logic or querying Klima/Carbonmark APIs directly when you need a single unified view with USDC pricing ready for downstream quoting and retirement workflows.

## Known failure modes

- No carbon classes or listings available if market liquidity is zero
- Stale data if the indexer has not refreshed recently
- Payment required error (402) if the x402 payment header is missing or invalid
- Network timeout from upstream Klima or Carbonmark APIs
- Truncated listings if fewer than 3 classes or listings are currently liquid

## How this service works

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.

## Output

A JSON object with a timestamp (asOf), an array of up to 3 Klima Protocol carbon classes (each with carbonClassId, name, category, country, indicative USDC price per tonne, and liquidity in tonnes), an array of up to 3 Carbonmark marketplace listings (each with listingId, projectName, creditId, registry, vintage, country, category, firm USDC price per tonne, tonnes left to sell, minimum fill, and expiry), plus endpoint discovery links and a note.

## Request schema (JSON Schema)

```json
{
 "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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {},
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "asOf",
      "classes",
      "listings",
      "endpoints",
      "note"
     ],
     "properties": {
      "asOf": {
       "type": "string"
      },
      "note": {
       "type": "string"
      },
      "classes": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "carbonClassId",
         "name",
         "category",
         "country",
         "priceUsdcPerTonne",
         "priceUsdcPerTonneFormatted",
         "priceBasis",
         "liquidityTonnes",
         "creditCount"
        ],
        "properties": {
         "name": {
          "anyOf": [
           {
            "type": "string"
           },
           {
            "type": "null"
           }
          ]
         },
         "country": {
          "anyOf": [
           {
            "type": "string"
           },
           {
            "type": "null"
           }
          ]
         },
         "category": {
          "anyOf": [
           {
            "type": "string"
           },
           {
            "type": "null"
           }
          ]
         },
         "priceBasis": {
          "type": "string",
          "const": "indicative"
         },
         "creditCount": {
          "type": "number"
         },
         "carbonClassId": {
          "type": "string"
         },
         "liquidityTonnes": {
          "type": "string"
         },
         "priceUsdcPerTonne": {
          "type": "string"
         },
         "priceUsdcPerTonneFormatted": {
          "type": "string"
         }
        },
        "additionalProperties": false
       }
      },
      "listings": {
       "type": "array",
       "items": {
        "type": "object",
        "required": [
         "listingId",
         "projectName",
         
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/klima-retirement-aggregator-catalog-0b201dd2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app](https://www.zero.xyz/host/x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/llms.txt)