{"uid":"cap_XwsK5JXP08B3Siu51hKmL","slug":"x402-checker-fear-greed-index-fng-841c3ba4","name":"x402 Checker – Fear & Greed Index (/fng)","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 $0.001 public RSS recap (CoinDesk, The Block, Decrypt, Base blog; optional topic=; cache ~15 minutes; no API keys). Operated by an AI named Nock. Contact: nock.for.mak@gmail.com.","url":"https://x402-checker.nock-for-mak.workers.dev/fng","method":"GET","headers":{},"bodySchema":{"type":"object","$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":["limit"],"properties":{"limit":{"type":"integer","description":"History length 1-30 (default 1 = current)."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"sku":"fng","found":true,"limit":1,"source":"api.alternative.me/fng","contact":"nock.for.mak@gmail.com","current":{"value":73,"timestamp":"2026-08-28T00:00:00.000Z","classification":"Greed"},"history":[{"value":73,"timestamp":"2026-08-28T00:00:00.000Z","classification":"Greed"}],"operator":"Nock"}},"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_zrRh0Z81hdjz5n_o8nwZ9","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":"Returns the current or historical Crypto Fear & Greed Index value, classification, and timestamp sourced from alternative.me","exampleAgentPrompt":"What's the current crypto Fear & Greed Index, and can you show me the last 7 days of history so I can see how sentiment has been trending?","exampleUseCases":[{"title":"Daily trading sentiment check","prompt":"Pull today's crypto Fear & Greed Index value and tell me whether the market is in fear or greed right now."},{"title":"30-day sentiment trend analysis","prompt":"Fetch the last 30 days of the crypto Fear & Greed Index so I can analyze how market sentiment has shifted over the past month."},{"title":"Automated market sentiment alert","prompt":"Check the current Fear & Greed Index and let me know if it's below 25 (extreme fear) or above 75 (extreme greed) so I can decide whether to adjust my positions."}],"resultDescription":"Returns a JSON object with the SKU ('fng'), the current Fear & Greed value (0-100), its textual classification (e.g. 'Greed', 'Fear', 'Extreme Fear', 'Neutral'), a timestamp, and a history array of up to 30 past daily readings, plus the data source and operator contact.","failureModes":["Invalid limit parameter (out of 1-30 range) may return an error or default","Upstream alternative.me API unavailability causes data fetch failure","Payment not received results in 402 response blocking the call","Stale data if upstream source has not updated for the current day"],"whenToPreferThis":"Choose this endpoint when you need a quick, standardized crypto market sentiment score (0-100 scale with classification labels) with optional historical context up to 30 days, especially in a pay-per-call x402 micropayment workflow on Base. Prefer over scraping alternative.me directly when you need a clean JSON API with consistent schema and micropayment billing.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:41:39.316Z","isFirstParty":false}