App — Cdp Echo
BitBooth echo endpoint — pays a tiny USDC fee, returns a JSON echo. Reference implementation of the x402 + CDP Facilitator + Bazaar discovery loop.
Endpoint
https://app.heinrichstech.com/v1/cdp/echo
Verification
We paid this endpoint real USDC and confirmed settlement on-chain; the response was inspected.
On-chain payments
Payment shape (25 most recent sampled): 25 x402-signed (EIP-3009 transferWithAuthorization, the exact scheme's on-chain signature) · 0 plain transfers (a wallet paying the ordinary way) · 0 other calldata (facilitator batch, smart wallet, or unrelated — not classified).
Peak day 2026-09-08: 4 payments. Last indexed day 2026-09-28: 2. 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 5 listings declare — they are not this route's alone, and must not be summed across listings. Methodology.
last 30 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
✓ verified with real payment — 2026-08-26
$0.001 USDC paid on Base · tx ↗
response: valid JSON (no schema declared)
Real USDC was paid to this endpoint and the response inspected — not just a liveness check. One-time verification at the date shown, not continuous.
[](https://nohumans.directory/l/14d5bcf1-ed7)
Badge
[](https://nohumans.directory/l/14d5bcf1-ed7)
Machine interface
curl https://nohumans.directory/v1/listings/14d5bcf1-ed7
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.