On April 17, 2026, OracleNet sent $0.005 USDC on Base to Headless Oracle and received five Ed25519-signed market-state attestations. No human in the loop. No account, no invoice, no purchase order. This page proves it — the signatures verify in your own browser.
Six interactions. Two participants. One protocol. Roughly 90 seconds.
Every detail is public. Click through to Basescan — the transaction is final.
Each receipt is an attestation of an exchange's live market status. Headless Oracle's public key is loaded from their /v5/keys endpoint ↗. Click verify on any card — your browser rebuilds the canonical payload, runs Ed25519.verify() locally with @noble/ed25519, and shows the result. Nothing is fetched from this server to determine validity.
The SHA-256 hash of the full deal record is committed to XRPL as a signed memo. If anyone ever modifies this page's data, the hash won't match — and the ledger never changes.
We sent the exact USDC on Base. The transaction confirmed. The Coinbase @x402/fetch SDK produced a valid EIP-3009 signature. LimitGuard's facilitator rejected it with Invalid signature — they run a custom validator with a non-standard payload shape. Three attempts with different header casings, three rejections. The USDC is still in their wallet.
So today we picked a counterparty that advertises X-X402-Foundation: compatible and publishes its spec. Their /v5/sandbox endpoint also turns any on-chain payment into a persistent API key — the perfect first-time-buyer path. First attempt: failed (the SDK's canonical path had a network-naming quirk). Second attempt via the raw-JSON direct path: success.
The M2M economy is real. The protocols haven't fully converged yet. We learn by trying.
Every step, including the failures before success.
The minimum viable M2M deal. You need a Base-compatible wallet with at least $0.005 USDC.
# 1. Send USDC on Base (any method: viem, ethers, MetaMask) # To: 0x26D4Ffe98017D2f160E2dAaE9d119e3d8b860AD3 Amount: 5000 units # 2. Exchange the TX hash for a persistent API key curl -X POST https://headlessoracle.com/v5/sandbox \ -H "Content-Type: application/json" \ -H 'X-Payment: {"txHash":"0x...","network":"base","amount":"5000","paymentAddress":"0x26D4Ffe98017D2f160E2dAaE9d119e3d8b860AD3"}' \ -d '{}' # 3. Use the key (1 call per credit) curl 'https://headlessoracle.com/v5/batch?mics=XNYS,XNAS,XLON' \ -H 'X-Oracle-Key: ho_crd_...'
x402 + EVM + cryptographic attestations compose cleanly when both sides implement the standard. The signing works. The server issues signed data. The buyer verifies locally.
5,000 units of USDC is the price of a signed market attestation. Everything above that is margin or brand. Machine-provided proof-carrying data costs fractions of a cent.
Headless Oracle's /v5/sandbox — "pay any amount, get a key" — is the cleanest onboarding path we've seen. New buyers don't fight the spec, they just transfer USDC.
Because the receipts are Ed25519-signed with a published key, neither seller nor buyer has to be trusted. This page doesn't ask you to trust us. The crypto on your device is the audit.
MCP infrastructure for AI agents. 100+ servers, 1,200+ tools. Made this call as a dependency-discovery test: what external x402 counterparties exist, and do they work?
Pre-trade market-state verification for 28 global exchanges. Ed25519-signed receipts with 60-second TTL, SEC/CFTC technical framework compliant.