Foundry

x402 seller due diligence: everything in x402-preflight PLUS on-chain proof of real demand (USDC actually received by the seller's payTo in the last 24h: payments, distinct payers, volume) and a Bazaar listing-truth audit (is this URL listed, does the listed price match what it charges). Reveals dead, fake or mispriced sellers before payment.

Base contract brief: base-contract-facts plus a plain-English explanation of who controls the contract and what they can do (mint, freeze, blacklist, change fees, upgrade the code), with things to verify. Grounded only in on-chain facts; never investment advice. Input: 0x address.

ERC-20 token info on Base mainnet from the chain: name, symbol, decimals, total supply, and whether the address is a contract at all. Input: 0x token address. Deterministic, no LLM, cheapest token lookup.

Real x402 demand from the chain: USDC an address (e.g. a seller's payTo) received on Base in the last 24 hours, with payment count, distinct payers, total, and top payers with the largest payer's share (a high share suggests self-testing or wash volume). Input: 0x address. Deterministic, no LLM.

x402 preflight: checks a paid x402 endpoint before a payment is signed. Probes it unpaid, parses the v1 body or v2 PAYMENT-REQUIRED header, lints every accepts[] option (network, canonical USDC, EIP-712 domain name/version that signatures verify against, EIP-55 payTo, zero payTo, amount, timeout, testnet, resource host) and returns ok/warn/block with reasons. Input: URL, optionally 'POST <url>'. D

Base contract fact sheet from the chain: is it a contract, proxy type (EIP-1967, beacon, EIP-1167 clone, ZeppelinOS) with implementation and admin, owner and whether ownership is renounced or held by a contract (multisig) or single key, privileged powers found in bytecode (mint, pause, blacklist, fee/tax setters, trading switch, tx limits, upgrade), current paused state, ERC-20 name/symbol/decimal

Base transaction explained from the chain: success or reverted, block and time, from, to, ETH value, method selector, gas used and fee, contract created, and every ERC-20 transfer decoded with token symbol and amount. Input: 0x transaction hash. Deterministic, no LLM.

Base address lookup from the chain: wallet (EOA) or contract, bytecode size, ETH balance, USDC balance and number of transactions sent. Useful before sending funds or paying an address. Input: 0x address. Deterministic, no LLM.

Current Base mainnet gas: latest block, base fee and priority fee in gwei, a suggested max fee, and the ETH cost of a typical USDC transfer. Input: any text, e.g. 'base'. Deterministic, no LLM.

Current time in any timezone: ISO time, unix timestamp, UTC offset, weekday. Input: IANA timezone, e.g. 'Europe/London'.

Programming joke: one short, safe-for-work developer joke per call. Input: any text.

DNS lookup: A, AAAA, MX, TXT, NS, CNAME, SOA or CAA records for a domain, via DNS-over-HTTPS. Input: 'example.com MX'.

Email validation: syntax, MX records, disposable domain and role account checks. Input: an email address.

Crypto price in USD for up to 20 coins (BTC, ETH, SOL...) or tokens by chain:address, from DefiLlama. Input: 'BTC,ETH'.

x402 listing doctor for sellers: why a paid endpoint gets no buyers. Runs the x402 preflight, Coinbase's CDP validator, and presence checks in the CDP Bazaar and 402index, then returns concrete fixes: 402 before input validation, Bazaar metadata, description over 500 chars or instruction-like, slow or sleeping host, no settled sale yet. Input: endpoint URL, optionally 'POST <url>'. Deterministic,

x402 market scan: for a topic, the top CDP Bazaar listings and who actually gets paid, measured on-chain: each seller's USDC received in the last 24 hours, payments and distinct payers, plus how many sellers earned nothing and the median price. Real demand before you build. Input: a topic, e.g. 'token security'. No LLM.

Daily x402 market report, measured on-chain: across 16 Bazaar topics, 80+ sellers, who earns (distinct payers, payments, USDC in 24 h), how many earn nothing, listing price bands, total USDC, distinct buyers and the biggest buying wallets. Refreshed hourly. Input: any text, e.g. 'today'. No LLM.

Quote: a short public-domain quote with its author (Franklin, Seneca, Curie, Newton...). Input: a topic word or 'any'.

Word count and text statistics: words, characters, sentences, paragraphs, reading time, top words. Input: any text.

JSON validator and formatter: checks JSON, reports the error line and column, returns pretty and minified forms. Input: JSON text.

Math calculator: safely evaluates an expression with + - * / % ^, parentheses, pi, e and functions like sqrt, sin, log. Input: '2^10 + sqrt(16)'.

Hash generator: md5, sha1, sha256, sha512, sha3-256, blake2b and keccak256 of a text. Input: any text.

JWT decoder: header, payload, issued and expiry times, and whether it has expired (signature not verified). Input: a JWT.

UUID generator: 1 to 50 random UUIDs, version 4 or time-ordered version 7. Input: '5' or 'v7 3'.

Base64 encoder and decoder, standard and URL-safe. Input: 'encode: text' or 'decode: aGVsbG8='.

Unit converter: length, mass, volume, temperature, time, data size, speed, area, energy, pressure. Input: '10 km to mi'.

User agent parser: browser and version, OS, device type, and whether it is a bot or AI crawler. Input: a User-Agent string.

Lorem ipsum placeholder text: 1 to 10 paragraphs. Input: number of paragraphs.

Color converter: hex, RGB and HSL, luminance, contrast against white and black, best text color. Input: '#1e90ff'.

Slug generator: turns any text into a clean URL slug. Input: a title.

Password generator: a strong random password (8 to 128 characters) with its entropy. Input: length, e.g. '24'.

Sunrise and sunset times in UTC for a location and date, with day length. Input: 'lat,lon' or 'lat,lon,YYYY-MM-DD'.

Currency exchange rates from the European Central Bank: convert an amount or list rates. Input: '100 USD to EUR'.

Public holidays for a country and year, with the next upcoming one. Input: country code and year, e.g. 'US 2026'.

English dictionary: definitions, part of speech, phonetics and synonyms for a word. Input: a word.

Wikipedia summary: the lead extract and link for a topic. Input: a topic or article title.

Book lookup by ISBN: title, authors, publisher, date and pages from Open Library. Input: an ISBN.

npm package info: latest version, license, dependencies count and weekly downloads. Input: a package name.

PyPI package info: latest version, license, Python requirement and recent downloads. Input: a package name.

arXiv paper search: top 5 papers with authors, date, link and abstract. Input: search words.

Hacker News top stories right now: title, link, points and comments. Input: how many, 1 to 10.

Recent earthquakes from USGS: magnitude, place, time and depth. Input: 'day', 'week' or 'significant'.

Weather now and the next hours for any location: temperature, wind, humidity, conditions (MET Norway). Input: 'lat,lon'.

Domain WHOIS via RDAP: registrar, creation and expiry dates, status and nameservers. Input: a domain.

IP address info: public or private, reverse DNS, ASN, network name, prefix and country. Input: an IPv4 or IPv6 address.

HTTP status check: is a URL up, its status code, redirect chain, latency and server. Input: a URL.

robots.txt checker: whether GPTBot, ClaudeBot, CCBot and other AI crawlers may crawl a site, plus sitemaps. Input: a domain or URL.

Website metadata: title, description, Open Graph image, canonical URL, favicon and language of a page. Input: a URL.

SSL certificate check: validity, issuer, expiry date and days left, SANs and TLS version. Input: a domain.

ENS resolver: name to Ethereum address, or address to primary ENS name. Input: 'vitalik.eth' or a 0x address.