# Services from chain.openverbs.com on Zero > chain.openverbs.com serves 22 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero. Canonical page: https://www.zero.xyz/host/chain.openverbs.com Live health (JSON, refreshed every minute): https://www.zero.xyz/host/chain.openverbs.com/health.json ## Services - [ENS Name Forward Resolution](https://www.zero.xyz/c/ens-name-forward-resolution-31c48b51/llms.txt): $0.003/call via x402. Resolves an ENS name (e.g. alice.eth, *.base.eth) to its Ethereum address by reading live from the ENS resolver on Ethereum mainnet - [EVM Transaction Gas Estimator](https://www.zero.xyz/c/evm-transaction-gas-estimator-bd8b1678/llms.txt): $0.004/call via x402. Simulates an EVM transaction using eth_estimateGas and returns estimated gas units and fee in wei/ETH, or a decoded revert reason if the transaction would fail. - [ERC-20 Token Balance Lookup](https://www.zero.xyz/c/erc-20-token-balance-lookup-07602cd5/llms.txt): $0.002/call via x402. Returns the live ERC-20 token balance (raw and decimal-formatted) held by a wallet address on a specified EVM chain - [OpenVerbs ENS Records Lookup](https://www.zero.xyz/c/openverbs-ens-records-lookup-43e3a777/llms.txt): $0.002/call via x402. Resolves an ENS name to its Ethereum address and text records (avatar, URL, email, Twitter, GitHub, etc.) in a single live call from the Ethereum mainnet resolver. - [Proxy Contract Detector & Implementation Resolver](https://www.zero.xyz/c/proxy-contract-detector-implementation-resolver-004bf935/llms.txt): $0.004/call via x402. Detects whether a smart contract is an upgradeable proxy and resolves its implementation address by reading EIP-1967, EIP-1822, OpenZeppelin legacy, and EIP-1167 minimal-proxy slots on-chain. - [ERC-20 Token Allowance Checker](https://www.zero.xyz/c/erc-20-token-allowance-checker-78009752/llms.txt): $0.002/call via x402. Returns the live on-chain spending allowance an owner has granted to a spender for a given ERC-20 token, including raw amount, decimal-formatted amount with symbol, and an unlimited-approval flag. - [Bitcoin Transaction Lookup by TXID](https://www.zero.xyz/c/bitcoin-transaction-lookup-by-txid-ffa16fc6/llms.txt): $0.006/call via x402. Looks up a Bitcoin transaction by its TXID and returns confirmation status, block height and time, fee, fee rate, size, weight, input/output counts, and total output value. - [chain.openverbs.com EVM Gas Conditions](https://www.zero.xyz/c/chain-openverbs-com-evm-gas-conditions-74af12ba/llms.txt): $0.002/call via x402. Returns live gas price, EIP-1559 base fee, and suggested max priority fee for a specified EVM chain in both wei and gwei. - [OpenVerbs NFT Metadata Resolver](https://www.zero.xyz/c/openverbs-nft-metadata-resolver-00596192/llms.txt): $0.006/call via x402. Resolves an NFT (contract address + tokenId) on a specified EVM chain into normalized metadata including name, description, image URL, attributes, and token standard (ERC-721 or ERC-1155). - [OpenVerbs Chain — ERC-20 Token Metadata](https://www.zero.xyz/c/openverbs-chain-erc-20-token-metadata-23830a3c/llms.txt): $0.002/call via x402. Reads live ERC-20 token metadata (name, symbol, decimals, total supply) directly from a contract on EVM chains, handling both string and legacy bytes32 encodings. - [Bitcoin Transaction Fee Rates & Cost Estimator](https://www.zero.xyz/c/bitcoin-transaction-fee-rates-cost-estimator-9da70f57/llms.txt): $0.006/call via x402. Returns live recommended Bitcoin fee rates (sat/vB) for five confirmation-speed tiers and estimates total fee cost for a transaction of a given virtual size. - [ENS Reverse Resolution](https://www.zero.xyz/c/ens-reverse-resolution-b776ef51/llms.txt): $0.003/call via x402. Reverse-resolves an Ethereum address to its primary ENS name by reading the reverse record live on Ethereum mainnet - [ERC-20 Token Risk Screener](https://www.zero.xyz/c/erc-20-token-risk-screener-d5e2bd71/llms.txt): $0.006/call via x402. Performs deterministic on-chain risk analysis of an ERC-20 token by inspecting its bytecode and metadata, flagging dangerous capabilities like blacklist/freeze, owner mint, pausability, and upgradeable proxies with severity scores and a verdict. - [chain.openverbs.com EVM Address State Lookup](https://www.zero.xyz/c/chain-openverbs-com-evm-address-state-lookup-381ef5d7/llms.txt): $0.002/call via x402. Returns live on-chain state for an EVM address: native balance (wei + ether), nonce/transaction count, and whether it's a contract or EOA with code size. - [OpenVerbs Chain Transaction Explainer](https://www.zero.xyz/c/openverbs-chain-transaction-explainer-3bd6b5ea/llms.txt): $0.006/call via x402. Decodes an on-chain transaction hash into plain-language summary including transfer type, decoded method, ERC-20/NFT token movements, gas cost, and status - [Bitcoin Address Balance & Activity Lookup](https://www.zero.xyz/c/bitcoin-address-balance-activity-lookup-f44358a0/llms.txt): $0.006/call via x402. Returns confirmed balance, total received/sent, transaction count, and unconfirmed/pending mempool data for a given Bitcoin address. - [Bitcoin Mempool Snapshot](https://www.zero.xyz/c/bitcoin-mempool-snapshot-0ba388dc/llms.txt): $0.006/call via x402. Returns a live snapshot of the Bitcoin mempool including unconfirmed transaction count, pending virtual size, block backlog, total pending fees, fee-rate histogram, and current chain tip height. - [chain.openverbs.com Transaction Receipt Lookup](https://www.zero.xyz/c/chain-openverbs-com-transaction-receipt-lookup-cc4a67c2/llms.txt): $0.003/call via x402. Fetches a live Ethereum/EVM transaction receipt by hash, returning status, gas usage, logs, block info, and contract address if created - [chain.openverbs.com EVM Transaction Lookup](https://www.zero.xyz/c/chain-openverbs-com-evm-transaction-lookup-465cff17/llms.txt): $0.003/call via x402. Fetches live on-chain status and full details of an EVM transaction by its hash, including success/failure, value, gas, and block info - [OpenVerbs Chain EVM Calldata Decoder](https://www.zero.xyz/c/openverbs-chain-evm-calldata-decoder-4af82f31/llms.txt): $0.004/call via x402. Decodes a 4-byte function selector or full EVM calldata into a human-readable function signature and decoded argument values, using a supplied ABI or public signature registries as fallback. - [chain.openverbs.com – eth_getLogs Contract Event Logs](https://www.zero.xyz/c/chain-openverbs-com-eth-getlogs-contract-event-logs-e0727f8e/llms.txt): $0.006/call via x402. Fetches raw and auto-decoded event logs for a specific contract address over a bounded block range on EVM chains, with optional topic filtering. - [OpenVerbs Chain Block Summary](https://www.zero.xyz/c/openverbs-chain-block-summary-970b1af3/llms.txt): $0.001/call via x402. Fetches a live block summary by number, hex, or tag from EVM chains, returning number, hash, parent, timestamp, transaction count, gas used/limit, base fee, and miner. Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. - [Zero catalog index](https://www.zero.xyz/llms.txt)