x402 authorization check on Base (chain 8453, $0.02)
x402 authorization check on Base (chain 8453, $0.02): the EIP-3009 authorization you will sign (from, to, value, validAfter, validBefore, nonce) + its 402 quote (payTo, amount, asset, network) -> SIGN/CAUTION/BLOCK: payTo / amount / asset / chain match, nonce unused, not expired, EIP-712 domain verified on-chain, look-alike USDC, balance, decoy >= $1, the digest you sign. Phrases: should I sign this, x402 authorization check, eip-3009, decoy quote. GET or POST JSON. Never charged on 4xx/5xx.
Answeringour last check, 2026-11-04
3 of 3checks answered this week
833 msmedian answer time
$0.02listed price per call
$0.02price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://agents.avasis.ai/v1/base/authorization-check
| Category | Market data |
|---|---|
| Provider host | agents.avasis.ai |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-11-04 | valid payment request | 402 | $0.02 | 848 ms |
| 2026-11-03 | valid payment request | 402 | $0.02 | 792 ms |
| 2026-11-02 | valid payment request | 402 | $0.02 | 833 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"amount": "20000",
"asset": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
"chain": "base",
"from": "0x8ec901f7e2710163387d70950f680f1ea2269d15",
"maxTimeout": 120,
"network": "eip155:8453",
"nonce": "0xa1b2c3d4a1b2c3d4a1b2c3d4a1b2c3d4a1b2c3d4a1b2c3d4a1b2c3d4a1b2c3d4",
"payTo": "0x6264191d6dd5427435b5e829077842e130ef1fc8",
"to": "0x6264191d6dd5427435b5e829077842e130ef1fc8",
"validBefore": "1793518925",
"value": "20000"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"additionalProperties": false,
"properties": {
"amount": {
"description": "the quote's accepts[].amount (v2) / maxAmountRequired (v1), atomic units: sets matches.amount",
"type": "string"
},
"asset": {
"description": "the quote's accepts[].asset (token contract)",
"type": "string"
},
"chain": {
"description": "optional; must be base / 8453 on this route",
"type": "string"
},
"domainChainId": {
"description": "optional domain.chainId of the typed data (must be this chain's)",
"minimum": 1,
"type": "integer"
},
"domainName": {
"description": "optional domain.name of the typed data (checked against the token's on-chain DOMAIN_SEPARATOR)",
"type": "string"
},
"domainVersion": {
"description": "optional domain.version of the typed data",
"type": "string"
},
"from": {
"description": "the payer: the wallet that signs (authorization.from) (0x + 40 hex)",
"type": "string"
},
"maxTimeout": {
"description": "the quote's accepts[].maxTimeoutSeconds: flags a validBefore longer than the seller asked for",
"minimum": 1,
"type": "integer"
},
"network": {
"description": "the quote's accepts[].network: base / eip155:8453 or ethereum / eip155:1",
"type": "string"
},
"nonce": {
"description": "authorization.nonce: 32 random bytes (0x + 64 hex), one per payment",
"type": "string"
},
"payTo": {
"description": "the quote's accepts[].payTo: sets matches.pay_to (BLOCK on mismatch)",
"type": "string"
},
"primaryType": {
"description": "TransferWithAuthorization or ReceiveWithAuthorization (default TransferWithAuthorization, the x402 exact scheme)",
"type": "string"
},
"to": {
"description": "the recipient (authorization.to; must equal the quote's payTo) (0x + 40 hex)",
"type": "string"
},
"validAfter": {
"description": "authorization.validAfter, unix seconds (default 0)",
"type": "string"
},
"validBefore": {
"description": "authorization.validBefore, unix seconds (x402 clients set now + maxTimeoutSeconds)",
"type": "string"
},
"value": {
"description": "authorization.value in atomic units (USDC has 6 decimals: 20000 = $0.02)",
"type": "string"
},
"verifyingContract": {
"description": "domain.verifyingContract: the token contract the typed data names (default USDC on this chain)",
"type": "string"
}
},
"required": [
"from",
"to",
"value",
"validBefore",
"nonce"
],
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"also_available": {
"type": "object"
},
"authorization": {
"type": "object"
},
"block_number": {
"type": "integer"
},
"block_timestamp": {
"type": "integer"
},
"chain": {
"type": "string"
},
"chain_id": {
"type": "integer"
},
"digest": {
"type": "object"
},
"domain": {
"type": "object"
},
"headline": {
"type": "string"
},
"kind": {
"type": "string"
},
"pay_to": {
"type": "object"
},
"payer": {
"type": "object"
},
"quote": {
"type": "object"
},
"rail": {
"type": "string"
},
"token": {
"type": "object"
},
"typed_data": {
"type": "object"
},
"verdict": {
"type": "object"
}
},
"required": [
"chain",
"verdict",
"authorization",
"quote",
"token",
"domain",
"typed_data",
"digest",
"headline"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}