Simulate a Base mainnet transaction before submitting it — real eth_estimateGas
Simulate a Base mainnet transaction before submitting it — real eth_estimateGas + eth_call against the given {to, data, value}, returns whether it would succeed, estimated gas, and estimated cost. POST body required. Experimental/informational only — not financial advice.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
293 msmedian answer time
$0.001listed price per call
$0.001price 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://api.nexismvp.com/market/gas-preflight
| Category | Market data |
|---|---|
| Provider host | api.nexismvp.com |
| 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 |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.001 | 293 ms |
Example input (from the provider)
{
"body": {
"chain": "base",
"data": "0x",
"to": "0x3B59f268EbC38c5F43B8B9bE37238bf43378Ad87",
"value": "0x0"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"properties": {
"chain": {
"description": "Only 'base' supported currently",
"enum": [
"base"
],
"type": "string"
},
"data": {
"description": "Call data, 0x-prefixed hex (default 0x)",
"type": "string"
},
"to": {
"description": "Target address",
"type": "string"
},
"value": {
"description": "Value in wei, 0x-prefixed hex (default 0x0)",
"type": "string"
}
},
"required": [
"to"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST",
"PUT",
"PATCH"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"properties": {
"estimated_cost_eth": {
"type": "number"
},
"estimated_gas": {
"type": "integer"
},
"revert_reason": {
"type": [
"string",
"null"
]
},
"will_succeed": {
"type": "boolean"
}
},
"required": [
"will_succeed"
],
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}