Receipt of a transaction: whether it succeeded or reverted, gas used, fee actually paid, and how many logs it emitted. The call that answers did my transaction work. Via eth_getTransactionReceipt.

Number of Addresses with Balance ≥ 100 — The number of unique addresses whose current native-asset balance is at least 100. Data by Glassnode.

CREDITS: pay $0.99 once and receive $1.25 of call balance (+25% bonus), spent via the X-API-Key header. One on-chain transaction, then zero settlement latency per request.

Name, symbol, decimals and total supply of any ERC20 contract in one call. Useful to label a token address before showing it to a user. Via eth_call.

Repair caller-supplied malformed JSON by safely removing an outer Markdown fence, comments, single-quoted strings, unquoted identifier keys, Python literals, and trailing commas, with transformation hashes and strict rejection of duplicate keys or non-finite numbers.

Geocode one structural address in the United States, Puerto Rico, or U.S. Island Areas with normalized U.S. Census MAF/TIGER coordinates, optional bounded state/county/tract/block/congressional geography, exact source attribution, and explicit range-interpolation limits.

Inspect Base transaction status and receipt evidence in one call, including success, revert, or pending state, confirmations, actual gas fee, recognized calldata, bounded ERC-20-shaped transfers, and official Base USDC recognition for payment confirmation.

Measure website response latency, payload size, compression, caching, and performance signals for a public URL.

Execute one bounded read-only eth_call against a resolved Base mainnet block, retain call and block evidence, and optionally decode caller-specified ABI output types.

Inspect Base mainnet contract bytecode, common token metadata, and ERC-165, ERC-721, and ERC-1155 interface signals at one resolved block.

Detect likely leaked API keys, tokens, private-key headers, JWTs, and credential assignments in caller-supplied source or configuration text. Return type, line, fingerprint, and a fully redacted preview with no network access or code execution.

Estimate gas for one Base mainnet transaction context at a resolved block, add a bounded caller-selected buffer, and preserve RPC rejection evidence without signing or broadcasting.

Decode a full 17-character VIN into normalized NHTSA vPIC make, model, year, body, engine, transmission, plant, fuel, and occupancy fields with official source evidence and explicit missing-data semantics.

Check one Base mainnet wallet or contract for ETH and official USDC balances, transaction nonce, and contract-bytecode evidence at a single resolved block.

Pay-per-call: Research brief (nano)

LLM inference at a flat $0.005 per call, with no account, no API key and no token metering. POST a prompt, get the completion: the same price for 10 tokens or 4000, while metered gateways scale with usage. Automatic failover across several large models; typical response under 1s. Pay per call in USDC over x402 - nothing to sign up for.

Wallet profile and PnL of a crypto trader ($0.01): track record in the DEX pools this API follows - realized and unrealized PnL, win rate, holding time and style (scalper, intraday, swing), open positions, PnL percentile, a label (SMART_MONEY, PROFITABLE, UNPROFITABLE) and daily net flow. Use before copying a wallet.

OpenAI's own transcription wire: POST multipart/form-data with a `file` part and get the transcript back. Point any Whisper-shaped SDK at this gateway and pay per call with USDC, no account and no API key. Same model and same four-minute cap as /api/transcribe, which takes a URL instead of an upload; /v1/pro/audio/transcriptions takes it to ten minutes.

Last N business days of US Treasury constant-maturity yields, oldest→newest. Source: FRED DGS* series (St. Louis Fed), public domain.

Paginated list of all indexed x402 resources