x402 Carbon Retirement API
Retire tokenized carbon credits on Base via Klima Protocol and the Carbonmark marketplace. GET /api/catalog returns the full endpoint directory (discover, quote, prepare-auth, POST actions/retire, certificate) plus a live snapshot of the top carbon classes and marketplace listings by liquidity, with USDC-per-tonne prices. Pay-per-call via x402 (USDC on Base).
Endpoint
https://x402.klimalabs.com/api/catalog
Free sample
https://x402.klimalabs.com/api/discover
Verification
Sustained protocol conformance over many checks from our infrastructure. Says nothing about content accuracy.
On-chain payments
Our own index of USDC Transfer events on Base to this payTo, updated every 10 minutes — watching since 2026-09-16; earlier history is still being backfilled, so these figures cover 1 day, not 30. Base USDC only — a seller settling elsewhere reads as quiet here. Methodology.
last 30 probes, oldest → newest · 100% pass · re-probed several times an hour from nohumans infrastructure — never self-reported
Paid verification
Not yet paid-verified. Probe-based status above is liveness only.
Badge
[](https://nohumans.directory/l/74dc8aa2-3f3)
Machine interface
curl https://nohumans.directory/v1/listings/74dc8aa2-3f3
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.