Ping, x402 payment test. A paid round-trip check: returns pong and the server time. Use to test that an x402 wallet, client or MCP setup can pay and receive a result.

Token analysis, token security. One call to analyse an ERC-20 token: name, symbol, decimals and supply, USD price from the deepest Uniswap v3 pool, whether it is an upgradeable proxy and who can upgrade it, and on Base the honeypot and contract risk checks (paused transfers, blacklist, owner fees, mint rights, liquidity). Give a ticker or 0x address and the network (base, eth, arb, op or polygon). Use before buying, listing or accepting an unknown token.

EVM developer utilities toolbox. One call that works out what an EVM value is and converts it every useful way: an address gets its EIP-55 checksum and bytes32 form; a signature its 4-byte selector and event topic; calldata is decoded (ERC-20, NFT, permit, EIP-3009); a bytes32 becomes uint256, address and units; a number converts between wei, gwei, ether (or any decimals) and hex; text gets keccak256. Local, no network. Use for building or debugging contracts and agents.

Crypto research, coin brief. One call to research a single coin traded on Hyperliquid (BTC, ETH, SOL, HYPE and about 200 more): price, 24-hour change, volume and open interest, the funding rate now and over the last 3 days, order-book depth and spread, technical readings on the 4-hour and daily charts (RSI, MACD, moving averages, Bollinger, volatility), and market-wide sentiment (Fear & Greed, attributed). Use before a trade or for a coin brief.

Token transfers, Arbitrum One. List a wallet's recent transfers of one ERC-20 token (default USDC) on Arbitrum One, in and out, over the last N blocks (1-2,000, default 1,000): direction, counterparty, amount and transaction, newest first, up to 50. Use to confirm a payment arrived or see what was sent; for the current balance use arb_token_balance. Malformed addresses are rejected with 400, uncharged.

Website screenshot. Render any public web page in a real headless Chrome browser, with JavaScript executed, and get a JPEG screenshot (1280 px wide, base64) plus the final URL, HTTP status and page title. Set fullPage=true to capture up to 4000 px of page height. Use for visual checks, page previews, monitoring and feeding pages to vision models.

Sanctions check (OFAC screening). OFAC sanctions screen for a crypto wallet before you pay it: checks an address (BTC, ETH, USDT, TRX and more) or a person or company name against the US Treasury SDN list, aliases included. Returns a verdict (block on a listed address, review on a name match, pass), each match with SDN ID, programs and match strength, and the list date. A screening aid, not legal advice. Use before paying; full verdict with wallet risk: check_counterparty.

Wallet portfolio value. USD value of a wallet on Base, Ethereum, Arbitrum or Optimism: native ETH plus major tokens (USDC and WETH everywhere, the common Base tokens on Base) and up to 20 tokens you add, each priced from its deepest Uniswap v3 pool, read live from the chain. Returns holdings, total and anything that could not be priced. Not a full token inventory. Use to check what a wallet is worth before trading, lending or paying.

Arbitrum One transaction receipt. Transaction receipt on Arbitrum One (eth_getTransactionReceipt): success or reverted, gas used, effective gas price, fee paid in ETH, number of event logs and any contract created. Use to confirm a payment or call went through; for sender, value and calldata use arb_tx. Input is a 0x-prefixed 64-hex hash; a pending or unknown hash returns 404, uncharged.

Eth call, Arbitrum contract call. Read-only contract call on Arbitrum One (eth_call): send ABI-encoded calldata to a contract at the latest block and get the raw return data, without a transaction or gas. Use to read any view function that has no dedicated tool (the example reads USDC totalSupply, selector 0x18160ddd); decode the result with the function's ABI. Calldata up to 8 KB; a call that reverts is 422 with the reason, uncharged.

Token allowance, Arbitrum ERC-20. ERC-20 token allowance on Arbitrum One: how much a spender may move from an owner's wallet (allowance), raw and in token units, and whether the approval is unlimited. Use to check an approval before a swap or to audit risky open approvals; for the owner's balance use arb_token_balance. Token is a ticker (USDC, USDT, WETH…) or a 0x contract; a missing contract is 404 and a non-ERC-20 422, both uncharged.

Estimate gas, Arbitrum. Estimate the gas a transaction would use on Arbitrum One (eth_estimateGas) and what it would cost at the current gas price, in gas units, gwei and ETH. Give to, plus value in ETH and calldata for a contract call, and the sender when the call depends on it. Use before sending a transaction or to price a batch; for the gas price alone use arb_gas. A transaction that would revert is 422 with the reason, uncharged.

Gas history, Arbitrum gas price. Gas price history on Arbitrum One (eth_feeHistory): base fee in gwei for each of the last N blocks (5-100, default 20), how full each block was, and the 10th, 50th and 90th percentile priority fees, with the low, average and high base fee over the window. Use to judge whether fees are rising, pick a priority fee or time a transaction; for the current price alone use arb_gas.

Arbitrum One contract check. Check whether a 0x address on Arbitrum One is a smart contract or a plain wallet: bytecode size, and whether it is an EIP-1167 minimal proxy and which implementation it points to. Use before sending funds or approving a spender; for a fuller risk verdict use check_counterparty. A malformed address is rejected with 400, uncharged.

Arbitrum One gas price. Current gas price on Arbitrum One (eth_gasPrice): gas price, base fee and suggested priority fee in gwei, plus what a plain ETH transfer (21,000 gas) costs right now. Takes no input. Use before sending a transaction or to decide whether to wait; for the fee a past transaction actually paid use arb_receipt.

Arbitrum One recent event logs. Recent contract event logs on Arbitrum One (eth_getLogs): the events a contract emitted over the last N blocks (1-1,000, default 50), optionally filtered by topic0 (the 0x 32-byte event signature hash). Returns up to 100 logs with block, transaction hash and topics. Use to watch transfers or contract events; for one transaction's outcome use arb_receipt.

Arbitrum One native balance. Native ETH balance (eth_getBalance) of any 0x wallet address on Arbitrum One at the latest block, in wei and in ETH. Use to check whether a wallet can pay gas or a transfer; for ERC-20 tokens use arb_token_balance, for all holdings at once use wallet_portfolio. A malformed address is rejected with 400, uncharged.

NFT balance, Arbitrum. How many NFTs of one ERC-721 collection a wallet holds on Arbitrum One (balanceOf), with the collection's name and symbol. Use to check a holder before a token-gated action or to see whether a wallet still holds a collection; for who holds one token id use arb_nft_owner. Both inputs are 0x addresses; a missing contract is 404, a contract that is not ERC-721 422, both uncharged.

Arbitrum One ERC-20 balance. ERC-20 token balance of a wallet on Arbitrum One (USDC, USDT, WETH or any token, via balanceOf): raw amount, decimals, symbol and the human-readable amount, live from the token contract. Use to check stablecoin or token holdings before a transfer or trade; for the native coin use arb_balance. Both inputs are 0x addresses (40 hex characters); no contract returns 404 and a non-ERC-20 contract 422, both uncharged.

Storage slot read, Arbitrum. Read one raw storage slot of a contract on Arbitrum One (eth_getStorageAt): the 32-byte word, as a number and, when it holds one, as an address. Slot is a decimal index or a 0x 32-byte key (mapping and proxy slots). Use to inspect contract state that has no getter, owners or implementation pointers; for proxies use arb_proxy. A malformed address or slot is rejected with 400, uncharged.