Ultron.
Tool reference / Ultron

simulate_call

Execute eth_call on a pinned Robinhood block. No signatures, spending permissions or broadcast.

Updated September 8, 2026 · Independent beta

Simulate a call

Execute eth_call on a pinned Robinhood block. No signatures, spending permissions or broadcast.

Permission and calling convention

Required scope: chain:read. This tool reads data or account-owned state.

This tool does not sign or broadcast a transaction. Check errors, source timestamps and explicit unavailable fields before using the result.

POST /api/tools/simulate_call
Authorization: Bearer <ULTRON_ACCESS_KEY>
Content-Type: application/json

Input schema

Inputs are validated against this current schema. Use exact values from live source results rather than substituting a ticker for a contract or a different chain.

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "to": {
      "type": "string",
      "pattern": "^0x[0-9a-fA-F]{40}$"
    },
    "from": {
      "type": "string",
      "pattern": "^0x[0-9a-fA-F]{40}$"
    },
    "data": {
      "type": "string",
      "maxLength": 8194,
      "pattern": "^0x([0-9a-fA-F]{2})*$"
    },
    "valueRaw": {
      "default": "0",
      "type": "string",
      "pattern": "^\\d{1,50}$"
    }
  },
  "required": [
    "to",
    "from",
    "data",
    "valueRaw"
  ],
  "additionalProperties": false
}

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