ToolAssay

Return bounded factual eth_estimateGas units and recent eth_feeHistory execution

Return bounded factual eth_estimateGas units and recent eth_feeHistory execution-fee evidence for one unsigned Ethereum or Base transaction. Not execution, signing, custody, trading, or a guaranteed final cost. Call when you need point-in-time gas units and recent execution-fee context before signing or submitting.

Answeringour last check, 2026-09-24
1 of 1checks answered this week
232 msmedian answer time
$0.005listed price per call
$0.005price 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.agentmercantile.com/v1/transaction-gas-preflight

CategoryCode and developer
Provider hostapi.agentmercantile.com
Networkseip155:8453
Payment schemesexact
Self-reported calls, 30 days2 from 2 payers (the provider's figure, not ours)

Our checks, last 30 days

DayResultHTTPAskedTime
2026-09-24 valid payment request 402$0.005 232 ms

Example input (from the provider)

{
  "body": {
    "chain": "eip155:8453",
    "data": "0x",
    "to": "0x0000000000000000000000000000000000000001",
    "value_wei": "0"
  },
  "bodyType": "json",
  "method": "POST",
  "type": "http"
}

Promised output schema (from the provider)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "properties": {
    "input": {
      "additionalProperties": false,
      "properties": {
        "body": {
          "additionalProperties": false,
          "properties": {
            "chain": {
              "description": "Analysis chain only. Payment remains Base eip155:8453.",
              "enum": [
                "eip155:1",
                "eip155:8453"
              ],
              "type": "string"
            },
            "data": {
              "description": "Optional 0x-prefixed even-length hex calldata. Default 0x. Maximum 8192 bytes. Request body maximum 20480 bytes.",
              "maxLength": 16386,
              "pattern": "^0x(?:[0-9a-fA-F]{2})*$",
              "type": "string"
            },
            "from": {
              "description": "Optional 0x-prefixed 20-byte sender used only as an eth_estimateGas field. No ownership is implied.",
              "pattern": "^0x[0-9a-fA-F]{40}$",
              "type": "string"
            },
            "to": {
              "description": "Required 0x-prefixed 20-byte destination. Contract creation is not supported.",
              "pattern": "^0x[0-9a-fA-F]{40}$",
              "type": "string"
            },
            "value_wei": {
              "description": "Optional unsigned base-10 integer string in the uint256 range. Default 0. JSON Schema cannot express the full uint256 upper bound; runtime validation rejects values above 2^256-1.",
              "pattern": "^(0|[1-9][0-9]*)$",
              "type": "string"
            }
          },
          "required": [
            "chain",
            "to"
          ],
          "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": true,
          "properties": {
            "chain": {
              "type": "object"
            },
            "fee_history": {
              "description": "Recent eth_feeHistory execution-fee evidence.",
              "type": [
                "object",
                "null"
              ]
            },
            "gas_estimate": {
              "description": "eth_estimateGas units when estimable.",
              "type": [
                "object",
                "null"
              ]
            },
            "illustrative_execution_fees": {
              "description": "Illustrative L2 execution-fee observations, not a guaranteed final cost.",
              "type": [
                "object",
                "null"
              ]
            },
            "limitations": {
              "items": {
                "type": "string"
              },
              "type": "array"
            },
            "machine": {
              "enum": [
                "VM06"
              ],
              "type": "string"
            },
            "methodology_version": {
              "enum": [
                "transaction-gas-preflight-0.1.0"
              ],
              "type": "string"
            },
            "request_shape": {
              "type": "object"
            },
            "status": {
              "enum": [
                "OK",
                "PARTIAL",
                "UNESTIMABLE",
                "HOLD"
              ],
              "type": "string"
            }
          },
          "required": [
            "status",
            "machine",
            "methodology_version",
            "chain",
            "gas_estimate",
            "limitations"
          ],
          "type": "object"
        },
        "type": {
          "type": "string"
        }
      },
      "required": [
        "type"
      ],
      "type": "object"
    }
  },
  "required": [
    "input"
  ],
  "type": "object"
}

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