signer 0xa036e2e3e19c6d02f30b3a9eb0acd057e6d9a5c8 ✓ attested by 0xc59c85e6…
Settlement
PayAI primary Dexter fallback* *premium tools only
01 · Operator checklist
progress: 0% — state persists in this browser
02 · The 402 handshake (live protocol trace)
actual exchange, actual values from this deployment
03 · Economics simulator (real curve, real params)
Simulation of p(t) under Poisson demand at the slider velocity — decay to floor between sales, ×bump on each settle, capped at ×5. Reference line: floor. This is the actual pricing formula the worker runs, not an illustration.
04 · Buyer integration (SDK snippets)
OFFICIAL SDK
CURL
MCP
VERIFY RECEIPT
npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";
const client = new x402Client();
client.register("eip155:*", new ExactEvmScheme(privateToAccount));
const api = wrapFetchWithPayment(fetch, client);
const r = await api("https://api.code402.dev/v1/tools/iban-check/call", {
method: "POST", headers: { "content-type": "application/json" },
body: JSON.stringify({ input: { iban: "GB82 WEST 1234 5698 7654 32" } }),
});
// 402 -> auto-sign (EIP-3009) -> auto-settle (USDC, Base) -> 200 + XDR-1 receipt
# 1 — call; the 402 body IS the payment quote
curl -s -X POST https://api.code402.dev/v1/tools/iban-check/call \
-H "content-type: application/json" \
-d '{"input":{"iban":"GB82 WEST 1234 5698 7654 32"}}'
# 2 — sign accepts[0] (EIP-3009 TransferWithAuthorization, USDC on Base)
# 3 — retry with X-PAYMENT: base64(voucher) -> 200 + receipt + tx
POST https://api.code402.dev/mcp (JSON-RPC 2.0)
{ "method": "tools/list" } // 28 tools, schemas, live
{ "method": "tools/call", "params": { "name": "iban_check",
"arguments": { "iban": "GB82 WEST 1234 5698 7654 32" } } }
// paywall arrives as isError:true carrying the x402 challenge —
// sign it, retry with the payment header, receipt comes with the result
receipt = { v:"XDR-1", tool, input_hash, output_hash, payer,
recipient, amount, nonce, ts, tier, signature, signer }
canonical = [v, tool, tool_version, input_hash, output_hash, payer,
recipient, amount, nonce, ts, tier].join("|")
recover(keccak256(canonical), signature) == signer // authentic
signer == published receipt_signing_address // ours (attested)
// every field verifiable offline — no trust in this server required
05 · Live price board (quotes at render)
Tool
Live quote
Floor
Ξ premium
receipt-verify
0.000000 USDC
0.000000
+0%
simulate-spend-sentinel
0.005000 USDC
0.005000
+0%
create-ap2-pilot
0.005000 USDC
0.005000
+0%
iban-check
0.005000 USDC
0.005000
+0%
assured-quote
0.005000 USDC
0.005000
+0%
assured-create
0.005000 USDC
0.005000
+0%
reconcile
0.010000 USDC
0.010000
+0%
lei-check
0.005000 USDC
0.005000
+0%
vat-mod97-check
0.005000 USDC
0.005000
+0%
company-number-format
0.005000 USDC
0.005000
+0%
rent-deposit-guard
0.020000 USDC
0.020000
+0%
rental-listing-risk
0.020000 USDC
0.020000
+0%
rental-verdict
0.050000 USDC
0.050000
+0%
batch-validate
0.050000 USDC
0.050000
+0%
swift-bic-check
0.005000 USDC
0.005000
+0%
aba-routing-check
0.005000 USDC
0.005000
+0%
ein-format-check
0.005000 USDC
0.005000
+0%
ifsc-check
0.005000 USDC
0.005000
+0%
abn-check
0.005000 USDC
0.005000
+0%
luhn-check
0.005000 USDC
0.005000
+0%
isbn-check
0.005000 USDC
0.005000
+0%
e164-check
0.005000 USDC
0.005000
+0%
sedol-check
0.005000 USDC
0.005000
+0%
cnpj-check
0.005000 USDC
0.005000
+0%
uscc-check
0.005000 USDC
0.005000
+0%
japan-corp-check
0.005000 USDC
0.005000
+0%
kra-pin-check
0.005000 USDC
0.005000
+0%
rfc-check
0.005000 USDC
0.005000
+0%
iso4217-currency-check
0.005000 USDC
0.005000
+0%
pre-disbursement-guard
0.005000 USDC
0.005000
+0%
vendor-onboarding-pack
0.020000 USDC
0.020000
+0%
india-supplier-check
0.020000 USDC
0.020000
+0%
china-supplier-check
0.020000 USDC
0.020000
+0%
japan-supplier-check
0.020000 USDC
0.020000
+0%
latam-supplier-check
0.020000 USDC
0.020000
+0%
gulf-supplier-check
0.020000 USDC
0.020000
+0%
africa-supplier-check
0.020000 USDC
0.020000
+0%
settlement-history-check
0.020000 USDC
0.020000
+0%
balance-check
0.005000 USDC
0.005000
+0%
erc20-balance
0.005000 USDC
0.005000
+0%
tx-activity
0.005000 USDC
0.005000
+0%
block-info
0.010000 USDC
0.010000
+0%
isin-check
0.005000 USDC
0.005000
+0%
ean13-check
0.005000 USDC
0.005000
+0%
gstin-check
0.005000 USDC
0.005000
+0%
crypto-ticker
0.010000 USDC
0.010000
+0%
context-distill
0.005000 USDC
0.005000
+0%
instant-json-schema-verifier
0.005000 USDC
0.005000
+0%
clean-markdown-scraper
0.015000 USDC
0.015000
+0%
fx-spot-price-oracle
0.010000 USDC
0.010000
+0%
create-b2b-invoice
0.005000 USDC
0.005000
+0%
get-b2b-invoice
0.005000 USDC
0.005000
+0%
calculate-fx-savings
0.005000 USDC
0.005000
+0%
aci-trust-lookup
0.005000 USDC
0.005000
+0%
dip-file-dispute
0.010000 USDC
0.010000
+0%
pod-verify-delivery
0.005000 USDC
0.005000
+0%
csp-commitment-create
0.005000 USDC
0.005000
+0%
iso20022-validate
0.010000 USDC
0.010000
+0%
iso20022-to-x402-intent
0.005000 USDC
0.005000
+0%
list-approved-insurers
0.005000 USDC
0.005000
+0%
quote-3rd-party-insurance
0.005000 USDC
0.005000
+0%
bind-insurance-policy
0.010000 USDC
0.010000
+0%
upi-vpa-check
0.005000 USDC
0.005000
+0%
pan-format-check
0.005000 USDC
0.005000
+0%
uae-trn-check
0.005000 USDC
0.005000
+0%
ofac-sdn-check
0.005000 USDC
0.005000
+0%
06 · Facilitator chain (probed at render — measured, not claimed)
probing…
Latency = client-side round-trip to each /supported at page load. Role = position in the worker's failover chain. *Dexter enforces a ~$0.00108 settlement floor — fallback viable for premium tools only.