Hearth Onchain Data

ERC20 token balance on Base. ERC20 balance of any wallet on Base, Ethereum, Arbitrum or Optimism (USDC by default) via balanceOf, with decimals applied. Deterministic, no LLM. Example output: {"chain":"base","wallet":"0x…","token":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","raw":"1500000","decimals":6,"balance":"1.5"}. Price: $0.0025 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "wallet": {
      "type": "string",
      "description": "Wallet address"
    },
    "token": {
      "type": "string",
      "description": "Token contract (default USDC)"
    }
  },
  "required": [
    "wallet"
  ]
}

ERC20 token metadata on Base. Name, symbol, decimals, total supply and bytecode presence for a token contract on Base, Ethereum, Arbitrum or Optimism. Deterministic, no LLM. Example output: {"chain":"base","address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","name":"USD Coin","symbol":"USDC","decimals":6,"totalSupply":"…","isContract":true}. Price: $0.004 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "address": {
      "type": "string",
      "description": "Token contract"
    }
  },
  "required": [
    "address"
  ]
}

Transaction status on Base. Status of a transaction on Base, Ethereum, Arbitrum or Optimism: pending/success/failed, block, confirmations, from/to, gas used, log count. Deterministic, no LLM. Example output: {"chain":"base","hash":"0x…","status":"success","blockNumber":1,"confirmations":10,"from":"0x…","to":"0x…","gasUsed":"21000","logs":0}. Price: $0.004 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "hash": {
      "type": "string",
      "description": "Transaction hash"
    }
  },
  "required": [
    "hash"
  ]
}

Wallet snapshot on Base. Native ETH balance, nonce (tx count) and whether the address is a contract, on Base, Ethereum, Arbitrum or Optimism. Deterministic, no LLM. Example output: {"chain":"base","address":"0x…","ethWei":"0","eth":"0","nonce":0,"isContract":false,"block":1}. Price: $0.0025 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "address": {
      "type": "string",
      "description": "Address"
    }
  },
  "required": [
    "address"
  ]
}

Gas price and fee estimate. Current gas price, base fee, suggested priority fee and EIP-1559 maxFee for Base, Ethereum, Arbitrum or Optimism, plus a 21000-gas transfer cost in native units. Deterministic, no LLM. Example output: {"chain":"base","block":1,"gasPriceGwei":"0.01","baseFeeGwei":"0.005","priorityFeeGwei":"0.001","maxFeeGwei":"0.011","transferCostEth":"0.00000021"}. Price: $0.001 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    }
  },
  "required": []
}

Latest block or block by number. Block number, timestamp, hash, tx count, gas used/limit and base fee for the latest (or given) block on Base, Ethereum, Arbitrum or Optimism. Deterministic, no LLM. Example output: {"chain":"base","number":1,"hash":"0x…","timestamp":1700000000,"iso":"2026-01-01T00:00:00.000Z","txCount":100,"gasUsed":"1","gasLimit":"1","baseFeeGwei":"0.01"}. Price: $0.001 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "number": {
      "type": "string",
      "description": "Block number (default latest)"
    }
  },
  "required": []
}

Token USD price. Current USD price for a token contract on Base, Ethereum, Arbitrum or Optimism (or the chain's native ETH if no address), with symbol, decimals and confidence. Aggregated from public DeFi price feeds. Deterministic, no LLM. Example output: {"chain":"base","address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","symbol":"USDC","priceUsd":0.9997,"decimals":6,"confidence":0.99,"timestamp":1700000000}. Price: $0.0035 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "address": {
      "type": "string",
      "description": "Token contract (omit for ETH)"
    }
  },
  "required": []
}

ENS / Basename resolve. Resolve an ENS name (vitalik.eth) or Basename (jesse.base.eth) to an address, or an address to its verified primary ENS name. On-chain, deterministic, no LLM. Example output: {"input":"vitalik.eth","name":"vitalik.eth","address":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","registry":"ethereum"}. Price: $0.0045 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "input": {
      "type": "string",
      "description": "Name (.eth / .base.eth) or 0x address"
    }
  },
  "required": [
    "input"
  ]
}

NFT owner (ERC-721). Current owner of an ERC-721 token (ownerOf) on Base, Ethereum, Arbitrum or Optimism. Deterministic, no LLM. Example output: {"chain":"base","contract":"0x…","tokenId":"1","owner":"0x…"}. Price: $0.0025 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "contract": {
      "type": "string",
      "description": "NFT contract"
    },
    "tokenId": {
      "type": "string",
      "description": "Token id (decimal)"
    }
  },
  "required": [
    "contract",
    "tokenId"
  ]
}

NFT metadata. tokenURI and resolved JSON metadata (name, description, image, attributes) for an ERC-721 or ERC-1155 token on Base, Ethereum, Arbitrum or Optimism. IPFS/Arweave resolved. Deterministic, no LLM. Example output: {"chain":"base","contract":"0x…","tokenId":"1","tokenUri":"ipfs://…","metadata":{"name":"…","image":"ipfs://…","imageUrl":"https://ipfs.io/ipfs/…","attributes":[]}}. Price: $0.007 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "contract": {
      "type": "string",
      "description": "NFT contract"
    },
    "tokenId": {
      "type": "string",
      "description": "Token id (decimal)"
    }
  },
  "required": [
    "contract",
    "tokenId"
  ]
}

Solana SOL balance. Native SOL balance (lamports and SOL) for any Solana address. Deterministic, no LLM. Example output: {"chain":"solana","address":"…","lamports":1000000000,"sol":"1","slot":1}. Price: $0.0025 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "address": {
      "type": "string",
      "description": "Solana address (base58)"
    }
  },
  "required": [
    "address"
  ]
}

Token safety / honeypot / rug-risk check. Scam check for an ERC20 on Base, Ethereum, Arbitrum or Optimism: honeypot, buy/sell tax, mintable, owner can change balances, proxy, blacklist, open source, holder concentration, LP lock. Returns a 0-100 risk score, a verdict (low/medium/high) and the flags behind it. Use before buying or accepting a token. Deterministic, no LLM. Example output: {"chain":"base","address":"0x8335…2913","name":"USD Coin","symbol":"USDC","riskScore":5,"verdict":"low","flags":["proxy contract"],"buyTax":0,"sellTax":0,"holders":11378198,"top10HolderPercent":41.2,"isHoneypot":false,"source":"goplus+onchain"}. Price: $0.009 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "address": {
      "type": "string",
      "description": "Token contract address"
    }
  },
  "required": [
    "address"
  ]
}

Multi-chain wallet portfolio with USD values. One call: ETH, WETH, USDC and USDT balances for an address across Base, Ethereum, Arbitrum and Optimism, each with a USD value, plus the total USD value and per-chain subtotals. Deterministic, no LLM. Example output: {"address":"0xd8dA…6045","totalUsd":15234.12,"chains":{"base":{"usd":120.5,"assets":[{"symbol":"ETH","amount":"0.05","usd":116.3}]}},"ethPriceUsd":2326}. Price: $0.008 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "address": {
      "type": "string",
      "description": "EVM wallet address"
    }
  },
  "required": [
    "address"
  ]
}

Recent ERC20 transfers for a token or wallet. Recent ERC20 Transfer events (decoded: from, to, amount with decimals, symbol, tx hash, block) for a token contract, a wallet, or both, over the last ~2,000 blocks on Base, Arbitrum or Optimism (~500 on Ethereum). Up to 50 newest. Deterministic, no LLM. Example output: {"chain":"base","fromBlock":1,"toBlock":2,"count":1,"transfers":[{"token":"0x…","symbol":"USDC","from":"0x…","to":"0x…","amount":"12.5","tx":"0x…","block":2}]}. Price: $0.0045 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "token": {
      "type": "string",
      "description": "Token contract (optional if wallet given)"
    },
    "wallet": {
      "type": "string",
      "description": "Wallet to filter (from or to)"
    },
    "blocks": {
      "type": "string",
      "description": "Lookback blocks (max 2000)"
    }
  },
  "required": []
}

DEX swap quote (Uniswap v3). Best Uniswap v3 single-hop quote for swapping amountIn of tokenIn to tokenOut on Base, Ethereum, Arbitrum or Optimism, checking all fee tiers (0.01/0.05/0.3/1%). Returns amountOut, effective price, best fee tier, gas estimate. Tokens: ETH, USDC, USDT or 0x address. Read-only quote; no swap is executed. Deterministic, no LLM. Example output: {"chain":"base","tokenIn":"WETH","tokenOut":"USDC","amountIn":"1","amountOut":"2325.41","price":2325.41,"feeTier":500,"gasEstimate":"90000","venue":"uniswap-v3"}. Price: $0.0045 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "tokenIn": {
      "type": "string",
      "description": "ETH, USDC, USDT or 0x address"
    },
    "tokenOut": {
      "type": "string",
      "description": "ETH, USDC, USDT or 0x address"
    },
    "amountIn": {
      "type": "string",
      "description": "Human amount of tokenIn, e.g. 1.5"
    }
  },
  "required": [
    "tokenIn",
    "tokenOut",
    "amountIn"
  ]
}

Contract verification and ABI. Whether a contract on Base, Ethereum, Arbitrum or Optimism is source-verified (Sourcify), its name, compiler, full ABI, function and event signatures, and its EIP-1967 proxy implementation (also looked up). Deterministic, no LLM. Example output: {"chain":"base","address":"0x…","isContract":true,"verified":true,"match":"exact_match","name":"FiatTokenProxy","compiler":"0.6.12","proxyImplementation":"0x…","functions":["admin()"],"events":["Upgraded(address)"],"abi":[]}. Price: $0.004 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "address": {
      "type": "string",
      "description": "Contract address"
    }
  },
  "required": [
    "address"
  ]
}

Explain a transaction in plain English (AI). Plain-English explanation of any transaction on Base, Ethereum, Arbitrum or Optimism: what happened, who sent what to whom (decoded token transfers with amounts and symbols), the method called, fee paid, and success/failure. Returns a summary plus the structured facts it is based on. Example output: {"chain":"base","hash":"0x…","summary":"Wallet 0xa729… sent 0.0009 USDC to 0x1074… (an x402 payment), settled by a facilitator. Succeeded; fee ~$0.0001.","facts":{"status":"success","method":"0xe3ee160e","transfers":[]}}. Price: $0.015 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "chain": {
      "type": "string",
      "description": "Chain: base (default), ethereum, arbitrum, optimism"
    },
    "hash": {
      "type": "string",
      "description": "Transaction hash"
    }
  },
  "required": [
    "hash"
  ]
}

Summarize a web page (AI). Fetch a public web page and return a concise summary: title, 3-7 key points, a one-paragraph TL;DR and the page's main entities. Good for research agents that need the gist of a URL cheaply. Example output: {"url":"https://example.com","title":"Example Domain","tldr":"…","keyPoints":["…"],"entities":["IANA"]}. Price: $0.015 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL"
    },
    "focus": {
      "type": "string",
      "description": "Optional focus/question"
    }
  },
  "required": [
    "url"
  ]
}

Extract structured JSON from a web page (AI). Fetch a public web page and extract the fields you name into clean JSON (e.g. fields=name,price,currency,availability or company,ceo,founded). Missing values come back as null. Up to 20 fields. Example output: {"url":"https://example.com","data":{"title":"Example Domain","contact_email":null,"description":"…"}}. Price: $0.02 USDC on Base via x402 (pass the payment in _meta["x402/payment"]).

{
  "type": "object",
  "properties": {
    "url": {
      "type": "string",
      "description": "Public http(s) URL"
    },
    "fields": {
      "type": "string",
      "description": "Comma-separated field names (max 20)"
    }
  },
  "required": [
    "url",
    "fields"
  ]
}