Discover / chain.openverbs.com

Contract bytecode and code hash

■ Challenge detected

Fetch deployed EVM contract runtime bytecode and its Keccak-256 code hash to fingerprint or compare contracts, or feed a disassembler. Supports Ethereum, Base, Arbitrum, Optimism and Polygon, with optional historical block reads. Returns full hex code, byte size and isContract; an empty-code address returns 0x and a null hash. Key-free RPC with endpoint fallback; code capped at 256 KiB.

x402
Base
USDC

Listed price: $0.006
Challenge detected: 9 of the last 9 checks
Median response: 178 ms
Last checked: 16 Oct, 13:59 UTC
In our index since: 26 Sept 2026

Endpoint

curl -i https://chain.openverbs.com/v1/bytecode
# 402 Payment Required: pay with an x402 client (USDC on Base),
# then send the same request again with the payment attached.

27 listed endpoints · on x402 Bazaar

Checks and payment terms on this page refer to the endpoint above. Other listed endpoints have not been checked individually.

Base URLhttps://chain.openverbs.com/v1

POST/token$0.002Live ERC-20 metadata read directly from the contract: name, symbol, decimals and total supply (raw + decimal-formatted). Handles both string and legacy bytes32 name/symbol encodings. Returns `isToken:false` for EOAs or non-token contracts. Reads live on-chain data with automatic endpoint fallback.
POST/btc-tx$0.006Look up a Bitcoin transaction by txid: confirmation status, block height and time, fee (sats), effective fee rate (sat/vB), size, weight and virtual size, input and output counts, and total output value (sats and BTC). On-chain ground truth for verifying a payment.
POST/gas$0.002Live gas conditions for an EVM chain: current gas price, the latest block's base fee (EIP-1559) and the suggested max priority fee — all in both wei and gwei. Ground truth an agent can't compute. Reads live on-chain data with automatic endpoint fallback.
POST/logs$0.006Query a contract's event logs over a bounded block range via `eth_getLogs`: filter by `address` (required) and optional `topics`, get back raw logs (topics, data, block, tx hash, log index) with ERC-20/721 Transfer logs auto-decoded to `{from, to, value}`. Block span is capped (large windows are clamped); results are capped by `limit`. Reads live on-chain data with automatic endpoint fallback.
POST/explain$0.006Decode a transaction into plain language: native ETH transfer, contract call (with decoded method name for common ERC-20/DEX functions like transfer, approve, swap, mint, multicall) or contract creation; ERC-20 and NFT (ERC-721) transfers it triggered (token, from, to, amount/tokenId from logs); gas spent in ETH; success/failed/pending; and a one-line summary. Reads live on-chain data with automatic endpoint fallback.
POST/decode$0.004Turn a 4-byte function selector or full calldata into its human-readable function signature, and (when calldata is present) the decoded argument values. Supply an `abi` for a fully deterministic offline decode, or omit it to look the selector up in public signature registries. Reads with automatic fallback.
POST/btc-fees$0.006Live recommended Bitcoin transaction fee rates (in sat/vB) for next-block, ~30-minute, ~1-hour, economy and minimum confirmation targets, straight from the mempool. Also estimates the total fee (in sats and BTC) for a transaction of the given virtual size, so an agent can pick a fee tier and know the cost before broadcasting.
POST/ens-records$0.002Read an ENS name's address plus its text records (avatar, url, email, description, com.twitter, com.github and more) in one call, live from the resolver on Ethereum mainnet. Pass `keys` to fetch specific records, or omit it for a sensible default set. Only records that are set are returned. Live reads with automatic endpoint fallback.
POST/gas-estimate$0.004Simulate a transaction before signing: runs `eth_estimateGas` for `{ to, from?, data?, value? }` and returns the estimated gas units and estimated fee (current gas price x gas, in wei + ETH). If the node rejects the call it returns `ok:false` with the decoded `revertReason` (why it would fail) instead of erroring. Reads live on-chain state with automatic endpoint fallback.
POST/tx$0.003Live status and details of a transaction by hash: success/failed/pending, from/to, value (wei + ether), nonce, block number, gas used, effective gas price and any created contract address. Returns `found:false` for unknown hashes. Reads live on-chain data with automatic endpoint fallback.
POST/ens-reverse$0.003Reverse-resolve an Ethereum address to its primary ENS name (the reverse record set by the owner), read live on Ethereum mainnet. Returns `found:false` when the address has no primary name set. Live reads with automatic endpoint fallback.
POST/token-allowance$0.002Live ERC-20 spending allowance an owner has granted a spender: calls `allowance(owner, spender)` on the token and returns the raw amount, a decimal-formatted amount (using the token's decimals) with its symbol, and an `isUnlimited` flag for effectively-infinite approvals. Use it to audit token approvals / approval risk before signing. Reads live on-chain data with automatic endpoint fallback.
POST/proxy$0.004Detect whether a contract is an upgradeable proxy and resolve its implementation: reads the standard EIP-1967 implementation/admin/beacon slots, EIP-1822 (UUPS), the OpenZeppelin legacy slot, and EIP-1167 minimal-proxy bytecode. Returns the proxy type, implementation, admin and beacon addresses when present. Reads live on-chain data with automatic endpoint fallback.
POST/btc-address$0.006Balance and activity for a Bitcoin address (base58 1…/3… or bech32 bc1…): confirmed balance (sats and BTC), total received and sent, confirmed transaction count, and unconfirmed/pending value and tx count from the mempool. On-chain ground truth an agent cannot compute locally.
POST/abi$0.006Get the verified contract ABI and verification metadata for a deployed contract by address, sourced from Sourcify. Returns the contract ABI (to decode or call it), contract name, compiler/language, match type, and proxy resolution (is-proxy plus implementation addresses). Supports Ethereum, Base, Arbitrum, Optimism, Polygon. Unverified contracts return `verified:false`. Live reads with cache fallback.
POST/nft-metadata$0.006Resolve one NFT (contract + tokenId) into normalized metadata: name, description, image, attributes and token standard (ERC-721 or ERC-1155). Reads the on-chain tokenURI/uri, then fetches and normalizes the metadata document (ipfs/ar/http/data), rewriting ipfs image links to a gateway URL. Returns `found:false` for non-NFT contracts. Live reads with automatic endpoint fallback.
POST/receipt$0.003Live transaction receipt by hash via `eth_getTransactionReceipt`: success/failed status, block number, from/to, created contract address, gas used, cumulative gas, effective gas price (wei + gwei), tx type and the emitted event logs (capped). Complements `tx` (which reads the transaction itself). Returns `found:false` for unknown/pending hashes. Reads live on-chain data with automatic endpoint fallback.
POST/address$0.002Native ETH / wallet balance for an address on any EVM chain: native balance (wei + ether), transaction count (nonce), and whether it's a contract or an externally-owned account (with deployed code size). Reads live on-chain data with automatic endpoint fallback.
POST/bytecode$0.006Fetch deployed EVM contract runtime bytecode and its Keccak-256 code hash to fingerprint or compare contracts, or feed a disassembler. Supports Ethereum, Base, Arbitrum, Optimism and Polygon, with optional historical block reads. Returns full hex code, byte size and isContract; an empty-code address returns 0x and a null hash. Key-free RPC with endpoint fallback; code capped at 256 KiB.
POST/ens-resolve$0.003Resolve an ENS name (like alice.eth) to its Ethereum address, read live from the ENS resolver on Ethereum mainnet. Offchain names such as *.base.eth resolve too. Returns `found:false` (a real answer, not an error) when the name has no address record. Live reads with automatic endpoint fallback.
POST/token-risk$0.006Deterministic risk screen of an ERC-20 token from on-chain bytecode and metadata, no third-party risk API. Flags privileged or abuse capabilities: blacklist/freeze, owner mint, pausable transfers, upgradeable proxy and a privileged owner, plus tokens missing symbol/decimals or code. Returns each flag with a severity, a 0-100 score and a verdict. Reads live on-chain data with automatic endpoint fallback.
POST/source$0.006Get the verified Solidity/Vyper source code for a deployed contract by address, sourced from Sourcify. Returns every source file (path + content), the contract name, language, compiler version and compiler settings (optimizer, evmVersion) — the full human-readable source an agent needs to read, audit or feed to an LLM. Supports Ethereum, Base, Arbitrum, Optimism, Polygon. Unverified contracts return `verified:false`. Live reads with cache fallback.
POST/btc-mempool$0.006Live snapshot of the Bitcoin mempool: number of unconfirmed transactions, total pending virtual size (bytes and MB), the current backlog in blocks, total fees pending (sats and BTC), the fee-rate histogram, and the current chain tip height. Lets an agent gauge network congestion and time a transaction.
POST/read-contract$0.006Call a read-only (view/pure) function on any deployed contract via eth_call and get the decoded result. Give the contract address and a human-readable signature (e.g. 'balanceOf(address) view returns (uint256)') plus args; include return types to decode outputs, else raw hex is returned. Reads allowances, oracle prices and vault/DAO state. Read-only, no signing. Ethereum, Base, Arbitrum, Optimism, Polygon.
POST/sanctions$0.006Screen a crypto wallet address against the OFAC SDN sanctions list (US Treasury Specially Designated Nationals) before transacting. Multi-chain across ~20 assets (BTC, ETH, USDT, TRX, XMR and more); EVM 0x addresses match case-insensitively. Returns whether the address is sanctioned plus the listed entity, asset and list publish date. Clean address returns `sanctioned:false`. Public-domain OFAC data.

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Showing 25 of 27 listed endpoints. Next endpoints

Agents can find it through the Superstables MCP server and JSON API: GET /api/v1/services/chain.openverbs.com

Recent checks

30 Sept 2026One bar per check, showing up to 20 recent checks. Coloured bars show relative response time, with a minimum visible height; full-height grey bars mean no challenge was detected. “Challenge detected” means HTTP 402 or another detected payment-challenge signal.16 Oct 2026

All 9 checks

When (UTC)	Result	HTTP	Response
16 Oct, 13:59 UTC	Challenge detected	402	169ms
15 Oct, 04:47 UTC	Challenge detected	402	174ms
13 Oct, 20:45 UTC	Challenge detected	402	323ms
11 Oct, 12:57 UTC	Challenge detected	402	202ms
10 Oct, 00:46 UTC	Challenge detected	402	178ms
8 Oct, 21:32 UTC	Challenge detected	402	181ms
7 Oct, 21:31 UTC	Challenge detected	402	191ms
6 Oct, 18:37 UTC	Challenge detected	402	175ms
30 Sept, 17:04 UTC	Challenge detected	402	173ms

Questions

Did our last probe detect a payment challenge?

At our last probe on 16 Oct, 13:59 UTC, it returned HTTP 402 or another detected payment-challenge signal. This check did not test payment, delivery or compatibility with the Superstables client.

What price is recorded for Contract bytecode and code hash?

Its listed price is $0.006.

What payment terms does Contract bytecode and code hash advertise?

The listing advertises x402, Base and USDC. It names cdp as its facilitator. Check the seller's current payment challenge and authentication requirements before paying.

Where is Contract bytecode and code hash listed?

In x402 Bazaar. Superstables first indexed it on 26 Sept 2026.

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