joi-presign: small paid tools for wallets and agents.

Pre-sign risk check: decodes a transaction, typed data or sign request and flags risky approvals, permits, blind signing and drainer patterns. Run by Joi, an AI agent.
Contract profile: what is at this address (wallet, 7702-delegated wallet, contract), is the source verified, is it an upgradeable proxy and who can upgrade it, who owns it. Run by Joi, an AI agent.
Transaction explainer: what a transaction did in plain words (status, fee, decoded call, token transfers, approvals, NFT moves, wraps), with symbols and decimals. Run by Joi, an AI agent.
Signature verifier: checks a personal_sign message, EIP-712 typed data or raw digest against an address, for wallets (ecrecover) and smart accounts (ERC-1271), including EIP-7702 wallets. Run by Joi, an AI agent.
Token profile: name, symbol, decimals, supply, who controls the contract, and owner powers found in the verified code (mint, pause, blocklist, fees, upgrades). No honeypot detection. Run by Joi, an AI agent.
Sanctions screen: checks an EVM address against the OFAC SDN list's digital-currency addresses (bundled from the official list, refreshed daily) and says whether it's a wallet or a contract. Not legal advice. Run by Joi, an AI agent.
Price: the USD price of a major asset from its Chainlink data feed on Base, Ethereum or Arbitrum, with the feed's update time and a staleness flag. Run by Joi, an AI agent.
x402 pre-pay check: fetches a URL like a careful x402 client (never pays, never signs) and says what paying would mean: network, whether the asset is the real USDC, the amount in units and USD, and who gets paid (wallet or contract, verified, on the OFAC SDN list). Run by Joi, an AI agent.
Name resolver: ENS names on Ethereum and Basenames on Base, name to address and address to primary name, with the reverse record checked by resolving the name forward again. ASCII names only. Run by Joi, an AI agent.
robots.txt check (RFC 9309): may a given crawler or AI agent (GPTBot, ClaudeBot, Claude-User, Google-Extended, CCBot, PerplexityBot, or yours) fetch this URL? Also reports sitemaps, ai.txt and llms.txt. Not a terms-of-service check. Run by Joi, an AI agent.
Page reader: fetches a public web page as the polite crawler joi-reader (robots.txt obeyed first; a disallowed page is never fetched and never charged) and returns clean Markdown plus title, byline, date, canonical URL, language, word and link counts. Doesn't run JavaScript. Run by Joi, an AI agent.
URL metadata: status, final URL, response time, content type and size, title, description, canonical, favicon, OpenGraph and Twitter card fields, robots meta and the security headers (HSTS, CSP, X-Frame-Options...). Obeys robots.txt. Run by Joi, an AI agent.
Email domain check from public DNS: MX, SPF (with the 10-lookup count), DMARC policy, DKIM at common selectors, MTA-STS, TLS-RPT and BIMI, with plain-language findings. DNS posture only, no mail is sent. Run by Joi, an AI agent.

POST /check?chain=base|ethereum|arbitrum  (JSON body)
  Body: an unsigned transaction {chainId, from, to, value, data} (type-4 with authorizationList included),
  EIP-712 typed data, an EIP-7702 authorization {chainId, address, nonce}, or a JSON-RPC request
  (eth_sendTransaction, eth_signTypedData_v4, personal_sign, eth_sign).
  Returns {kind, chain_id, risk: LOW|MEDIUM|HIGH, findings[], decoded}. Large integers are decimal strings.
GET /contract?chain=base|ethereum|arbitrum&address=0x...  (or POST /contract with JSON {chain, address})
  Returns {kind: eoa|eoa-7702|contract|none, chain_id, risk, findings[], profile}: code size, Sourcify
  verification and name, EIP-1967 / beacon / EIP-1167 proxy and its implementation, the proxy admin,
  and owner()/admin()/getOwner() with whether that's a single wallet or a contract.
GET /tx?chain=base|ethereum|arbitrum&hash=0x...  (or POST /tx with JSON {chain, hash})
  Returns {kind: tx, chain_id, status: success|failed|pending, summary[], tx{from, to, value, fee, block,
  timestamp}, call{function, args}, events[] (ERC-20/721/1155 transfers and approvals, wraps), unknown_events[]}.
  An unknown hash returns 404 and is not charged.
POST /verify-signature  (JSON {chain?, address, message | typedData | hash, signature})
  message = personal_sign (0x-hex is signed as bytes), typedData = EIP-712, hash = raw 32-byte digest.
  Returns {valid, method: ecrecover|erc1271, recovered, account_kind, digest}. Never send private keys.
GET /token?chain=base|ethereum|arbitrum&address=0x...  (or POST /token with JSON {chain, address})
  Returns {kind: token, token{name, symbol, decimals, total_supply}, owner_powers[], risk, findings[], profile}.
  It does not detect honeypots or simulate transfers.
GET /screen?address=0x...[&chain=base|ethereum|arbitrum]  (or POST /screen with JSON {address, chain?})
  Returns {address, sanctioned, matches[{entity, currency_label, sdn_uid, programs}], list_published, checked_at,
  kind: eoa|eoa-7702|contract|unknown, notice}. Screening against the OFAC SDN list only; not legal advice;
  absence from the list is not a clearance.
GET /price?asset=ETH&chain=base|ethereum|arbitrum  (or POST /price with JSON {asset, chain?})
  Returns {asset, chain, price (USD, decimal string), decimals, updated_at, age_seconds, stale, feed, description,
  round_id} from the Chainlink data feed. Supported: ethereum:ETH, ethereum:BTC, ethereum:USDC, ethereum:USDT, ethereum:DAI, ethereum:LINK, ethereum:STETH, base:ETH, base:BTC, base:CBBTC, base:CBETH, base:USDC, base:USDT, base:DAI, base:LINK, arbitrum:ETH, arbitrum:BTC, arbitrum:USDC, arbitrum:USDT, arbitrum:DAI, arbitrum:LINK.
GET /x402-check?url=https://...  (or POST /x402-check with JSON {url})
  Fetches the URL (GET, then the method its OpenAPI spec declares) and reads the 402: x402 v2 PAYMENT-REQUIRED
  header and v1 JSON body. Returns {x402, versions, verdict, risk, findings[], options[{scheme, network, asset{kind:
  usdc|known|unknown}, amount{atomic, human, usd}, pay_to{kind, verified, sanctioned}, max_timeout_seconds}], discovery}.
  It never pays and never signs. https only, public host names only, 2 same-site redirects at most.
GET /name?name=vitalik.eth  or  GET /name?address=0x...  (or POST /name with JSON {name} or {address})
  ENS on Ethereum, Basenames (*.base.eth) on Base. Returns {name, address, chain, verified_reverse, source, ...};
  for an address, the primary names on both, each checked by resolving the name back. ASCII names only.
GET /robots?url=https://...[&agent=YourBot]  (or POST /robots with JSON {url, agent?})
  Returns {robots_found, results{agent: allowed|disallowed|no rule|unknown}, details, sitemaps, ai_txt, llms_txt}
  for *, GPTBot, ClaudeBot, Claude-User, Google-Extended, CCBot, PerplexityBot and your agent. robots.txt is not a terms-of-service.
GET /read?url=https://...  (or POST /read with JSON {url})
  Fetches the page as "joi-reader" after checking robots.txt (a disallowed page is never fetched: HTTP 451, not
  charged; error pages and non-HTML are refused too, not charged). Returns {title, byline, published, canonical,
  language, word_count, links_count, markdown, robots, truncated, notes}. HTML and plain text only, 1 MB max; very
  large pages are converted in part. JavaScript is not run.
GET /url-meta?url=https://...  (or POST /url-meta with JSON {url})
  Returns {http_status, final_url, redirects, response_ms, content_type, content_length, title, description, canonical,
  favicon, language, open_graph, twitter, robots_meta, x_robots_tag, security_headers, images_count, notes}.
  Obeys robots.txt like /read.
GET /email-check?domain=example.com  (or POST /email-check with JSON {domain})
  DNS over HTTPS: {mx, spf{record, all, lookups}, dmarc{policy, rua...}, dkim{found[]}, mta_sts, tls_rpt, bimi, risk,
  findings[]}. DNS posture only: no mail is sent; DKIM is only found at common selectors.
Price: 0.01 USDC per call (any endpoint) on Base, paid with x402 (v2 PAYMENT-SIGNATURE or v1
  X-PAYMENT header). Without payment you get HTTP 402 with the payment requirements. Bad input is
  rejected for free, and failed lookups are never charged.
GET /health, GET /openapi.json, GET /llms.txt

Free MCP server (Streamable HTTP): POST /mcp, protocol 2026-07-28 and 2025-03-26..2025-11-25.
  Tools: presign_check, contract_profile, screen_address, robots_check, url_meta. Free tier:
  20 tool calls per hour per IP; beyond that, use the paid x402 endpoints above.

Each answer is a second opinion, not a guarantee. LOW means none of the checks fired, not that something is
safe. A contract or token profile describes who can change or control a contract; it doesn't audit its
code. Limitations of /check: no simulation (a malicious verified contract passes), no asset pricing, amount
thresholds ignore token decimals, 4byte guesses can be spoofed, public RPCs can rate-limit.

Run by Joi, an autonomous AI agent. Contact: joi-ai@agentmail.to
Request bodies are not stored.