MCPFax On-Chain Toolkit

FREE, no payment. Describe in your own words the data you are trying to buy — anything, not just on-chain data — and get back whether we operate a service that supplies it, with the MCP endpoint if so. Every request is catalogued so repeatedly-requested data gets built. Nothing identifying is stored, only the words of the request.

{
  "type": "object",
  "properties": {
    "need": {
      "type": "string",
      "description": "What you are looking for.",
      "examples": [
        "live electricity spot prices by ZIP"
      ]
    }
  },
  "required": [
    "need"
  ],
  "additionalProperties": false
}

FREE, no payment. The aggregate of what agents have told us they are looking for, most-requested first, with the categories nothing available yet serves.

{
  "type": "object",
  "properties": {
    "days": {
      "type": "string",
      "description": "Window in days, default 30, max 90.",
      "examples": [
        "30"
      ]
    }
  },
  "additionalProperties": false
}

Live gas price on Ethereum, Base, Arbitrum, Optimism or Polygon — in wei and gwei, plus what a plain 21,000-gas transfer would cost in the native token, which is the number you actually budget with. Pass several chains comma-separated to compare where to execute. Call this immediately before sending a transaction: gas moves every block, so the answer is good for seconds, not minutes. Costs $0.005 USDC per call via x402 on Base.

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "One or more of ethereum, base, arbitrum, optimism, polygon — comma-separated, e.g. 'base,ethereum'. Defaults to base.",
      "examples": [
        "base"
      ]
    }
  },
  "additionalProperties": false
}

Read an ERC-20's name, symbol, decimals and total supply straight from the contract on the chain you name, and confirm the address actually has code there. Use before quoting an amount or building a transfer: getting decimals wrong is the classic way to send 1,000,000x the intended value. An address with no code, or a contract that is not an ERC-20, is reported as such and is NOT charged. Costs $0.005 USDC per call via x402 on Base.

{
  "type": "object",
  "properties": {
    "address": {
      "type": "string",
      "description": "0x-prefixed 20-byte contract address.",
      "examples": [
        "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
      ]
    },
    "chain": {
      "type": "string",
      "description": "ethereum, base, arbitrum, optimism or polygon. Defaults to base.",
      "examples": [
        "base"
      ]
    }
  },
  "required": [
    "address"
  ],
  "additionalProperties": false
}

Status of a transaction by hash: success, failed or still pending, with the block it landed in, sender and recipient, value moved, gas used, the fee actually paid, and how many logs it emitted. Use to confirm an action you took really settled rather than assuming it did. An unknown hash is reported as not_found and is NOT charged. Costs $0.005 USDC per call via x402 on Base.

{
  "type": "object",
  "properties": {
    "hash": {
      "type": "string",
      "description": "0x-prefixed 32-byte transaction hash.",
      "examples": [
        "0x08001b920b214572ff2e7a4fc4560bafa717619b00b91561425ef6a325fdfedb"
      ]
    },
    "chain": {
      "type": "string",
      "description": "ethereum, base, arbitrum, optimism or polygon. Defaults to base.",
      "examples": [
        "base"
      ]
    }
  },
  "required": [
    "hash"
  ],
  "additionalProperties": false
}

Native balance, the next nonce to use, and whether the address holds contract code — the three things needed before sending from or to an address. Pass 'token' as well to read an ERC-20 balance for the same address in the same call. Values are read at the latest block, so a reorg can change them. Costs $0.008 USDC per call via x402 on Base.

{
  "type": "object",
  "properties": {
    "address": {
      "type": "string",
      "description": "0x-prefixed 20-byte address.",
      "examples": [
        "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"
      ]
    },
    "chain": {
      "type": "string",
      "description": "ethereum, base, arbitrum, optimism or polygon. Defaults to base.",
      "examples": [
        "base"
      ]
    },
    "token": {
      "type": "string",
      "description": "Optional ERC-20 contract address to also report that token's balance.",
      "examples": [
        "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
      ]
    }
  },
  "required": [
    "address"
  ],
  "additionalProperties": false
}