API integration engineering · api-integration
Evaluate caller-supplied x402 payment requirements before a wallet signs them. Use after receiving HTTP 402 to enforce a maximum USDC amount, allowed networks, exact scheme, recipient presence, and an optional expiry buffer. Returns eligible accepts and explicit blockers for $0.002 USDC via x402 on Base; it never signs, pays, stores, or echoes a payment signature.
One-command purchase
No account or API key. AgentCash reads the 402 challenge, pays no more than the declared cap, retries the request and returns the result.
npx agentcash@latest fetch https://api.delx.ai/api/v1/x402/payment-preflight -m POST -H 'x-delx-source: product-page' --max-amount 0.002 -b '{"requirements":{"accepts":[{"scheme":"exact","network":"eip155:8453","amount":"1000","payTo":"0x1111111111111111111111111111111111111111","expires":1786272600}]},"max_amount_usdc":0.002,"allowed_networks":["eip155:8453"],"now_epoch_seconds":1786272500}'{
"requirements": {
"accepts": [
{
"scheme": "exact",
"network": "eip155:8453",
"amount": "1000",
"payTo": "0x1111111111111111111111111111111111111111",
"expires": 1786272600
}
]
},
"max_amount_usdc": 0.002,
"allowed_networks": [
"eip155:8453"
],
"now_epoch_seconds": 1786272500
}{
"schema": "delx/util-x402-payment-preflight/v1",
"approved": true,
"evaluated_count": 1,
"eligible_count": 1,
"selected": {
"index": 0,
"scheme": "exact",
"network": "eip155:8453",
"amount_usdc": "0.001",
"pay_to": "0x1111111111111111111111111111111111111111",
"expiry_status": "ok"
},
"evaluations": [
{
"index": 0,
"scheme": "exact",
"network": "eip155:8453",
"amount_usdc": "0.001",
"pay_to_present": true,
"expiry_status": "ok",
"blockers": []
}
],
"policy": {
"max_amount_usdc": "0.002",
"allowed_networks": [
"eip155:8453"
],
"asset_decimals": 6,
"min_expiry_seconds": 30,
"expiry_checked": true
}
}Machine-readable evidence