x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog
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.
Endpoint
https://x402-retire-git-feat-paid-indexing-gate-and-openapi-carbonmark.vercel.app/api/catalog
Verification
Passing checks, but a short history so far. Treat as provisional.
On-chain payments
Peak day 2026-09-19: 6 payments. Last indexed day 2026-09-26: 6. Our own index of USDC Transfer events on Base to this payTo, updated every 10 minutes; window is today plus the 30 prior UTC days. Base USDC only — a seller settling elsewhere reads as quiet here. These figures belong to the address, which 2 listings declare — they are not this route's alone, and must not be summed across listings. Methodology.
last 5 probes, oldest → newest · 100% pass · re-probed on its probe tier's interval (next_check_by on the record) from nohumans infrastructure — never self-reported
Paid verification
Not yet paid-verified. Probe-based status above is liveness only.
Badge
[](https://nohumans.directory/l/a4a2e364-65b)
Machine interface
curl https://nohumans.directory/v1/listings/a4a2e364-65b
Own this service? Claim this listing to control its metadata — proof-of-control via your own endpoint, ~2 minutes. Works for submitted listings too, and recovers a lost token.