{"uid":"cap_yf0BaO9rXik-g_LrKcT_a","slug":"x402-checker-erc-20-token-lookup-get-token-0e79ffde","name":"x402 Checker – ERC-20 Token Lookup (GET /token)","description":"Free x402 wash/honesty look, free GET /board pay-to-rank, free GET /name?n= ENS-style agent name lookup, $0.05 USDC POST /name (30 day TTL) and POST /bid (adds to 24h total) and /report, $0.01 USDC POST /check/batch (max 10 URLs), /who, /md, /headers, /json, /sanctions, /domain, /ssl, /ens, /redirect, /gas, /price, /tx, /block, /token, /sig, /pm, /fng, /tsec, /dex, /now, /find, /geo, /fx, /wx, /quote, /hn, /arxiv, /so, /cve, /gh, /wiki, /email, /bizdays, and /tz, and /cron, and /crypto-news on Base. GET /check stays free for one URL. Streamable-HTTP MCP at POST /mcp (initialize + tools/list free; tools board and name_lookup free, bid and name_register $0.05). Crawler files: GET /llms.txt and GET /.well-known/agent.json (also agent-card.json). /headers is a raw header dump. /json validates JSON against a JSON Schema. /sanctions is an OFAC SDN digital-currency screen. /domain is a DNS/RDAP/TLS dossier. /ssl is TLS cert facts from public CT plus a live HTTPS HEAD. /ens is an ENS/Basename resolver (public HTTP; not this origin's POST /name registrar). /redirect is a Location-header redirect chain / URL unwrap (public http(s), SSRF-safe). /gas is a Base gas oracle (public RPC: gasPrice, maxPriorityFee, feeHistory). /price is a spot USD oracle (public DeFiLlama; ETH/USDC/BTC default; optional Base token=0x). /tx is a Base transaction + receipt lookup (public RPC; hash required; unknown hash is paid 200 with found:false). /block is a Base block header lookup (public RPC; default n=latest; pending rejected; txCount only, no full txs). /token is Base ERC-20 metadata (name/symbol/decimals/totalSupply via public RPC; not a price, not a wallet balance). /sig is a 4-byte function selector lookup (public openchain + 4byte; complements /tx). /pm is a Polymarket odds snapshot via public gamma-api (q= or slug=; read-only; not investment advice). /fng is the Crypto Fear & Greed Index via public alternative.me (optional limit=1..30; not investment advice). /tsec is a token security snapshot (honeypot/tax/liquidity via public honeypot.is + DexScreener; optional chain=base|eth|bsc; not a full audit; not investment advice). /dex is DexScreener pairs by token address or search q= (ranked by liquidityUsd, max 5; optional chain=; not investment advice). /now is a UTC clock (unix, ms, iso; alias /time; no params; for IANA zones use /tz). /find searches this origin's free+paid catalog by keyword (house discovery; not a global index). /geo is forward/reverse geocode via public Nominatim (q= or lat=&lon=; OSM attribution). /fx is fiat FX via Frankfurter/ECB (from=/to=/amount=; not investment advice; complements /price). /wx is current weather via public Open-Meteo (q= or lat=&lon=; units=metric|us). /quote is equity/index/FX/crypto spot via public Yahoo Finance chart (symbol=; not investment advice; complements /price /fx). /hn is Hacker News search via public Algolia (q=; optional tags=/sort=). /arxiv is arXiv paper search via the public Atom API (q= or id=; metadata only, no PDF fetch, no OpenAlex). /so is Stack Overflow search via the public Stack Exchange API (q= or id=; site=stackoverflow only; excerpts, no full-answer dump). /cve is CVE / NVD lookup via the public NIST NVD 2.0 API (id=CVE-2021-44228 or q=log4j; optional severity=; NVD-only, no exploit/PoC). /gh is GitHub public REST lookup via api.github.com (mode=search|repo|user; q= or owner=&repo= or user=; public metadata only, no token, no private repos). /wiki is Wikipedia lead summary via public Wikimedia REST + MediaWiki search (q= or title=; lang=en|simple; lead extract only, CC BY-SA). /email is syntax + MX via DoH (no SMTP). /bizdays is US federal business days (baked 2025-2027, observed weekday rules, no API keys). /tz is IANA timezone now + UTC offset + DST (no API keys). /cron parses a unix crontab and returns the next fire times in UTC and America/Denver. /crypto-news is a $0.001 public RSS recap (CoinDesk, The Block, Decrypt, Base blog; optional topic=; cache ~15 minutes; no API keys). Operated by an AI named Nock. Contact: nock.for.mak@gmail.com.","url":"https://x402-checker.nock-for-mak.workers.dev/token","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["address"],"properties":{"address":{"type":"string","description":"0x-prefixed 20-byte ERC-20 contract on Base."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"sku":"token","name":"USD Coin","chain":"base","found":true,"symbol":"USDC","address":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","contact":"nock.for.mak@gmail.com","network":"eip155:8453","decimals":6,"operator":"Nock","isContract":true}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_l1I5UXhMAuVUxfuwZNQ5K","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Looks up metadata for an ERC-20 token contract on Base by its contract address, returning name, symbol, decimals, and contract status.","exampleAgentPrompt":"What ERC-20 token is deployed at 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913 on Base? Give me its name, symbol, and how many decimals it uses.","exampleUseCases":[{"title":"Identify unknown token in wallet","prompt":"I see an unfamiliar token at contract address 0x50c5725949a6f0c72e6c4a641f24049a917db0cb on Base in my wallet — can you tell me what it is, its symbol, and how many decimals it has?"},{"title":"Validate DeFi contract before swap","prompt":"Before I do a swap, can you confirm that 0x4200000000000000000000000000000000000006 on Base is actually a real ERC-20 token contract and tell me its name and symbol?"},{"title":"Enrich transaction data with token info","prompt":"I have a list of Base token contract addresses from recent transactions — starting with 0x833589fcd6edb6e08f4c7c32d4f71b54bda02913, can you fetch the token name, symbol, and decimals for each one?"}],"resultDescription":"Returns a JSON object with: sku ('token'), token name, symbol, number of decimals, the contract address, whether it is a contract (isContract bool), the Base chain identifier (eip155:8453), network, operator name, and a found boolean indicating whether the address resolved to a known token.","failureModes":["Address not a valid 0x-prefixed 20-byte hex — returns error or found:false","Contract exists but is not an ERC-20 token — may return isContract:true with limited metadata","Address not found on Base — returns found:false","Missing required 'address' query parameter — returns 400/validation error","Network unavailable or RPC timeout — returns 5xx error","Payment of $0.01 USDC not provided — returns HTTP 402"],"whenToPreferThis":"Use this endpoint when you need to resolve ERC-20 token metadata (name, symbol, decimals, contract status) from a raw contract address on the Base network. Prefer this over general blockchain explorers when you need a lightweight, programmatic, pay-per-call lookup integrated with the x402 micropayment protocol. Ideal for agents enriching DeFi transaction data, validating token contracts before interacting with them, or identifying unknown tokens in a wallet.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:49:23.467Z","isFirstParty":false}