Check read-only ERC-20 wallet readiness for a planned token spend
Check read-only ERC-20 wallet readiness for a planned token spend.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
262 msmedian answer time
$0.002listed price per call
$0.002price 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
POST https://blockchain-api.x402-chain-tools.workers.dev/chain/wallet-preflight
| Category | Market data |
|---|---|
| Provider host | blockchain-api.x402-chain-tools.workers.dev |
| Networks | eip155:8453, solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp |
| 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 |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.002 | 262 ms |
Example input (from the provider)
{
"body": {
"amount": "10.5",
"spender": "0x0000000000000000000000000000000000000003",
"token": "0x0000000000000000000000000000000000000002",
"wallet": "0x0000000000000000000000000000000000000001"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"amount": {
"description": "Positive decimal string without scientific notation. Exact fractional precision depends on the token decimals() response.",
"pattern": "^[0-9]+(?:\\.[0-9]+)?$",
"type": "string"
},
"spender": {
"description": "Planned spender address.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
},
"token": {
"description": "ERC-20 token contract address on Base.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
},
"wallet": {
"description": "Base wallet address.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
}
},
"required": [
"wallet",
"token",
"spender",
"amount"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"additionalProperties": false,
"properties": {
"allowance": {
"additionalProperties": false,
"properties": {
"formatted": {
"pattern": "^[0-9]+(?:\\.[0-9]+)?$",
"type": "string"
},
"raw": {
"pattern": "^[0-9]+$",
"type": "string"
},
"sufficient": {
"type": "boolean"
},
"unlimited": {
"type": "boolean"
}
},
"required": [
"raw",
"formatted",
"unlimited",
"sufficient"
],
"type": "object"
},
"issues": {
"items": {
"enum": [
"NO_NATIVE_GAS_BALANCE",
"INSUFFICIENT_TOKEN_BALANCE",
"INSUFFICIENT_ALLOWANCE",
"SPENDER_NOT_CONTRACT"
]
},
"type": "array"
},
"limitations": {
"maxItems": 2,
"minItems": 2,
"prefixItems": [
{
"const": "native gas check only verifies a non-zero ETH balance"
},
{
"const": "transaction execution is not simulated"
}
],
"type": "array"
},
"native_balance": {
"additionalProperties": false,
"properties": {
"eth": {
"pattern": "^[0-9]+(?:\\.[0-9]+)?$",
"type": "string"
},
"has_native_gas_balance": {
"type": "boolean"
},
"wei": {
"pattern": "^[0-9]+$",
"type": "string"
}
},
"required": [
"wei",
"eth",
"has_native_gas_balance"
],
"type": "object"
},
"network": {
"const": "eip155:8453",
"type": "string"
},
"ok": {
"const": true,
"type": "boolean"
},
"ready": {
"type": "boolean"
},
"requested_amount": {
"additionalProperties": false,
"properties": {
"decimals": {
"maximum": 255,
"minimum": 0,
"type": "integer"
},
"formatted": {
"pattern": "^[0-9]+(?:\\.[0-9]+)?$",
"type": "string"
},
"raw": {
"pattern": "^[0-9]+$",
"type": "string"
}
},
"required": [
"formatted",
"raw",
"decimals"
],
"type": "object"
},
"spender": {
"description": "Spender address.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
},
"spender_is_contract": {
"type": "boolean"
},
"token": {
"description": "Token contract address.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
},
"token_balance": {
"additionalProperties": false,
"properties": {
"formatted": {
"pattern": "^[0-9]+(?:\\.[0-9]+)?$",
"type": "string"
},
"raw": {
"pattern": "^[0-9]+$",
"type": "string"
},
"sufficient": {
"type": "boolean"
}
},
"required": [
"raw",
"formatted",
"sufficient"
],
"type":