Check an unsigned Base mainnet transaction before signing or broadcasting
Check an unsigned Base mainnet transaction before signing or broadcasting. Simulates with eth_call, estimates gas, checks sender balance and target bytecode, decodes supported token transfers and approvals, flags unlimited approvals and suspicious transaction shapes, and returns PASS, REVIEW, or FAIL. Never signs or broadcasts.
Not tested: has real-world effectsour last check, 2026-09-24
0 of 0checks answered this week
n/amedian answer time
$0.01listed price per call
n/aprice it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
GET https://machinemint-native-x402-production.up.railway.app/v1/base-preflight
| Category | Market data |
|---|---|
| Provider host | machinemint-native-x402-production.up.railway.app |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 3 from 3 payers (the provider's figure, not ours) |
Our checks, last 30 days
We never call tools that send, buy, move money or file anything, not even without paying.
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"data": "0x",
"from": "0x4200000000000000000000000000000000000006",
"to": "0x1111111111111111111111111111111111111111",
"value": "0"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET"
],
"type": "string"
},
"queryParams": {
"additionalProperties": false,
"description": "Optional GET query parameters. Omit all fields to request the deterministic marketplace-verification sample.",
"properties": {
"chain": {
"default": "base",
"enum": [
"base",
"base-mainnet"
],
"type": "string"
},
"data": {
"default": "0x",
"description": "0x-prefixed calldata.",
"pattern": "^0x(?:[0-9a-fA-F]{2})*$",
"type": "string"
},
"from": {
"description": "Sender wallet for the unsigned transaction.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
},
"to": {
"description": "Target contract or account.",
"pattern": "^0x[0-9a-fA-F]{40}$",
"type": "string"
},
"value": {
"default": "0",
"description": "Native value in wei.",
"type": [
"string",
"integer"
]
}
},
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"action": {
"type": "object"
},
"canonical_endpoint": {
"type": "string"
},
"chain": {
"type": "object"
},
"gas": {
"type": "object"
},
"provenance": {
"type": "object"
},
"reason_codes": {
"items": {
"type": "string"
},
"type": "array"
},
"request_mode": {
"enum": [
"provided_transaction",
"marketplace_verification_sample"
],
"type": "string"
},
"risks": {
"items": {
"type": "object"
},
"type": "array"
},
"sender": {
"type": "object"
},
"service": {
"const": "machinemint.evm.preflight"
},
"simulation": {
"type": "object"
},
"target": {
"type": "object"
},
"transaction": {
"type": "object"
},
"verdict": {
"enum": [
"PASS",
"REVIEW",
"FAIL"
],
"type": "string"
}
},
"required": [
"service",
"verdict"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}