# Services from api.kadec0.xyz on Zero

> api.kadec0.xyz serves 45 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/api.kadec0.xyz
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/api.kadec0.xyz/health.json

## Services

- [Congress Stock Trades API](https://www.zero.xyz/c/congress-stock-trades-api-05e0b46f/llms.txt): $0.05/call via x402, rated 4.3/5 (1 review). Returns US congressional stock trade disclosures (STOCK Act filings) filterable by politician, ticker, chamber, transaction type, and date range.
- [Author and Researcher Profile Search (OpenAlex)](https://www.zero.xyz/c/author-and-researcher-profile-search-openalex-620cf65c/llms.txt): $0.02/call via x402, rated 4.0/5 (1 review). Searches for academic researchers by name, returning affiliation, publication count, citation metrics (h-index, i10-index), and top-cited papers for author lookup and disambiguation.
- [Academic & Scientific Paper Search API](https://www.zero.xyz/c/academic-scientific-paper-search-api-fb7d04ce/llms.txt): $0.02/call via x402. Searches academic and scientific papers across arXiv, PubMed, OpenAlex, Crossref, and Semantic Scholar in a single deduplicated, ranked call
- [SERP Batch Search](https://www.zero.xyz/c/serp-batch-search-a9696151/llms.txt): $0.1/call via x402. Runs up to 5 web or news search queries in a single API call, returning ranked title, URL, and snippet per query with locale, freshness, and safesearch controls.
- [Paper Citation Lookup & Reference Graph](https://www.zero.xyz/c/paper-citation-lookup-reference-graph-4514a060/llms.txt): $0.03/call via x402. Given a DOI, arXiv ID, OpenAlex ID, or PMID, returns a paper's full metadata, reference list (works it cites), citing-works list (recent papers that cite it), and citation count.
- [Multi-Agency Consumer Product Recalls Feed](https://www.zero.xyz/c/multi-agency-consumer-product-recalls-feed-d93acb1b/llms.txt): $0.02/call via x402. Returns normalized recall records across FDA, CPSC, and NHTSA agencies — including product, reason, company, classification, and severity — with optional text search and agency filtering.
- [Crypto Token Price Lookup via CoinPaprika](https://www.zero.xyz/c/crypto-token-price-lookup-via-coinpaprika-f1ddd654/llms.txt): $0.01/call via x402. Returns live price, market cap, 24h volume, and 24h change for one or more crypto tokens by coin ID or symbol, sourced from CoinPaprika, with no API key required.
- [Current Time & Timezone API](https://www.zero.xyz/c/current-time-timezone-api-773be3ce/llms.txt): $0.005/call via x402. Returns current time, date, and timezone data for any IANA timezone, city, or abbreviation, and performs timezone conversion, DST-aware date arithmetic, and timestamp diffing.
- [CVE Vulnerability Lookup API](https://www.zero.xyz/c/cve-vulnerability-lookup-api-f3876369/llms.txt): $0.01/call via x402. Looks up CVE security vulnerabilities from NIST NVD and GitHub Security Advisories, returning CVSS scores, severity, CWEs, and references.
- [DeFi TVL & Protocol Data via DefiLlama](https://www.zero.xyz/c/defi-tvl-protocol-data-via-defillama-9b73cbef/llms.txt): $0.02/call via x402. Returns total-value-locked (TVL), category, chain presence, and change metrics for DeFi protocols or chains via DefiLlama
- [DeFi Yield & APY Pool Lookup](https://www.zero.xyz/c/defi-yield-apy-pool-lookup-21a107aa/llms.txt): $0.03/call via x402. Fetches top yield-farming pools with APY, TVL, chain, project, and asset data from DefiLlama, filterable by chain, project, symbol, and stablecoin status.
- [Domain WHOIS and DNS Lookup](https://www.zero.xyz/c/domain-whois-and-dns-lookup-1a124afd/llms.txt): $0.02/call via x402. Returns WHOIS registration details and full DNS records for a given domain name
- [Email Validation API](https://www.zero.xyz/c/email-validation-api-4f499eb3/llms.txt): $0.03/call via x402. Validates up to 25 email addresses per call with RFC syntax checks, live MX lookups, disposable-domain detection, role-account flagging, and free-provider flagging, returning an ok/risky/invalid verdict per address.
- [openFDA Recalls & Adverse Events API](https://www.zero.xyz/c/openfda-recalls-adverse-events-api-d6398fae/llms.txt): $0.02/call via x402. Retrieves FDA recall and adverse-event records for drugs, devices, and food from openFDA, including classification, recalling firm, and reason.
- [Field & Topic Search for Research Papers](https://www.zero.xyz/c/field-topic-search-for-research-papers-8395fa1f/llms.txt): $0.02/call via x402. Resolves a broad field name or topic phrase against the OpenAlex taxonomy and returns a seed cluster of top-cited and recently-influential academic papers with full metadata.
- [GitHub Repository & User Data API](https://www.zero.xyz/c/github-repository-user-data-api-9467f4d7/llms.txt): $0.02/call via x402. Fetches GitHub repository stats, user profiles, and code-search results including stars, forks, language, topics, and issues via the GitHub REST API
- [Google Trends Interest by Region](https://www.zero.xyz/c/google-trends-interest-by-region-f1427195/llms.txt): $0.03/call via x402. Returns Google Trends subregional interest scores (0–100) for a keyword within a specified country, broken down by state or region.
- [Google Trends Interest Over Time](https://www.zero.xyz/c/google-trends-interest-over-time-b92770b0/llms.txt): $0.05/call via x402. Returns a dated time series (indexed 0–100) of Google search interest for a keyword, with configurable time window and optional country filter.
- [Google Trends Related Queries](https://www.zero.xyz/c/google-trends-related-queries-4178611d/llms.txt): $0.03/call via x402. Returns top (scored 0–100) and rising (% growth) related search queries from Google Trends for a given keyword and country
- [Google Trends Related Topics](https://www.zero.xyz/c/google-trends-related-topics-66edc848/llms.txt): $0.03/call via x402. Returns top (0-100 relative score) and rising (% growth) related topics for a keyword in a given country, including entity type metadata, sourced from Google Trends.
- [Literature Review Map](https://www.zero.xyz/c/literature-review-map-a91b7d4a/llms.txt): $0.08/call via x402. Returns a unified, deduplicated table of references, citations, and semantically related papers for a given seed paper or topic query in a single call.
- [Market Fear & Greed Index API](https://www.zero.xyz/c/market-fear-greed-index-api-fafec6f0/llms.txt): $0.05/call via x402. Returns aggregated investor sentiment scores from CNN Fear & Greed, Crypto Fear & Greed, and VIX volatility gauge, filterable by asset class.
- [Multi-Engine Metasearch (SERP Multi)](https://www.zero.xyz/c/multi-engine-metasearch-serp-multi-d8419a76/llms.txt): $0.05/call via x402. Fans out a single query across 2-3 search engines (Brave, Yahoo, Yandex) and returns deduplicated, consensus-ranked results via reciprocal-rank fusion with per-engine rank attribution.
- [Paper Full-Text & Open-Access PDF Retrieval](https://www.zero.xyz/c/paper-full-text-open-access-pdf-retrieval-06fefcd7/llms.txt): $0.04/call via x402. Retrieves the full readable body of an academic paper (split into sections) and its open-access PDF location, given an arXiv ID, DOI, OpenAlex ID, PMID, or PMCID.
- [Related Paper Discovery via Semantic Scholar / OpenAlex](https://www.zero.xyz/c/related-paper-discovery-via-semantic-scholar-openalex-cec1a258/llms.txt): $0.03/call via x402. Returns semantically similar and recommended scholarly papers for a given seed paper (arXiv ID, DOI, or OpenAlex ID) or topic query to support literature reviews and reading list expansion.
- [SEC EDGAR Filing Search](https://www.zero.xyz/c/sec-edgar-filing-search-262121d1/llms.txt): $0.05/call via x402. Full-text search of SEC filings (10-K, 10-Q, 8-K, and more) by company name, ticker, CIK, or keyword, returning form type, date, and document links
- [Smart Research Search](https://www.zero.xyz/c/smart-research-search-6d50cd48/llms.txt): $0.02/call via x402. Auto-routed academic paper search that either grounds a broad field term against OpenAlex taxonomy or runs hybrid retrieval with SPECTER2 reranking for natural-language research questions.
- [Stablecoin Supply & Chain Breakdown API](https://www.zero.xyz/c/stablecoin-supply-chain-breakdown-api-cd6ae54d/llms.txt): $0.02/call via x402. Returns circulating supply, peg mechanism, peg currency, and per-chain breakdown for stablecoins via DefiLlama
- [CoinGecko Trending Crypto Coins](https://www.zero.xyz/c/coingecko-trending-crypto-coins-8ef8ad0d/llms.txt): $0.01/call via x402. Returns the most-searched crypto coins on CoinGecko right now, including rank, price, and market-cap rank.
- [USGS Real-Time Earthquake Feed](https://www.zero.xyz/c/usgs-real-time-earthquake-feed-5c11c205/llms.txt): $0.005/call via x402. Fetches recent seismic events from the USGS earthquake catalog, filterable by magnitude, time range, and geographic radius, with tsunami flags.
- [Web Page to Markdown Converter (api.kadec0.xyz)](https://www.zero.xyz/c/web-page-to-markdown-converter-api-kadec0-xyz-3acfb47f/llms.txt): $0.03/call via x402. Fetches any public URL and returns its content as clean, LLM-ready markdown plus structured metadata — no API key required.
- [SERP + Page Reader (Search & Fetch in One Call)](https://www.zero.xyz/c/serp-page-reader-search-fetch-in-one-call-133ac02d/llms.txt): $0.08/call via x402. Runs a web search and fetches the full markdown content of top results in a single API call, returning ranked results with extracted page text.
- [Website SEO Audit API](https://www.zero.xyz/c/website-seo-audit-api-01e2b263/llms.txt): $0.08/call via x402. Performs an instant on-page SEO, performance, and accessibility audit for any given URL, returning title, meta tags, headings, links, image alt attributes, load time, issues list, and an overall score.
- [Weather Forecast & Air Quality API](https://www.zero.xyz/c/weather-forecast-air-quality-api-a8fea28d/llms.txt): $0.005/call via x402. Returns current weather conditions, a 16-day daily forecast, and air quality metrics (AQI, PM2.5, ozone) for any latitude/longitude coordinate.
- [Building Permit Records API (Chicago, NYC, Seattle, SF)](https://www.zero.xyz/c/building-permit-records-api-chicago-nyc-seattle-sf-34a51cf7/llms.txt): $0.03/call via x402. Retrieves building and construction permit records—including type, status, address, cost, and issue date—across Chicago, NYC, Seattle, and San Francisco.
- [Bulk WHOIS Lookup](https://www.zero.xyz/c/bulk-whois-lookup-970adcf9/llms.txt): $0.05/call via x402. Returns registrar, registration/expiry dates, and nameservers for up to 10 domains in a single batch call.
- [Hacker News Feed & Search](https://www.zero.xyz/c/hacker-news-feed-search-0d5bd769/llms.txt): $0.01/call via x402. Fetches top, new, or best front-page Hacker News stories, or searches full-text HN stories by keyword, returning titles, scores, comment counts, and authors.
- [Company Domain Enrichment API](https://www.zero.xyz/c/company-domain-enrichment-api-02d466bd/llms.txt): $0.15/call via x402. Returns firmographic data, tech-stack detection, social profiles, and metadata for a given company domain in a single API call.
- [DNS Propagation Checker](https://www.zero.xyz/c/dns-propagation-checker-0a312667/llms.txt): $0.03/call via x402. Checks DNS propagation status for a domain by querying multiple public resolvers (Google, Cloudflare, Quad9, OpenDNS) and comparing results to detect propagation lag or split-horizon discrepancies.
- [Ethereum Gas Price Oracle](https://www.zero.xyz/c/ethereum-gas-price-oracle-fb0bd0a0/llms.txt): $0.01/call via x402. Returns current Ethereum base fee and EIP-1559 priority-fee estimates (slow, standard, fast) in gwei
- [api.kadec0.xyz Geocoding & Reverse Geocoding](https://www.zero.xyz/c/api-kadec0-xyz-geocoding-reverse-geocoding-c300d896/llms.txt): $0.01/call via x402. Converts a place name or address to latitude/longitude coordinates (forward geocoding), or converts coordinates back to a human-readable address (reverse geocoding).
- [Stack Overflow Q&A Search via api.kadec0.xyz](https://www.zero.xyz/c/stack-overflow-q-a-search-via-api-kadec0-xyz-8b8d48f2/llms.txt): $0.01/call via x402. Searches Stack Overflow questions and answers using the Stack Exchange API, returning scored Q&A pairs with accepted-answer flags, tags, and full answer bodies.
- [USDA FoodData Central Nutrition Lookup](https://www.zero.xyz/c/usda-fooddata-central-nutrition-lookup-6400e697/llms.txt): $0.01/call via x402. Returns calories, macronutrients, and micronutrients for any food by querying the USDA FoodData Central database
- [api.kadec0.xyz SERP Web Search](https://www.zero.xyz/c/api-kadec0-xyz-serp-web-search-ed9bb9e9/llms.txt): $0.05/call via x402. Returns ranked web search results (title, URL, snippet) for a given query string, keyless via x402 micropayment.
- [YouTube Video Data Extractor (api.kadec0.xyz)](https://www.zero.xyz/c/youtube-video-data-extractor-api-kadec0-xyz-a4f081f0/llms.txt): $0.03/call via x402. Fetches YouTube video metadata and caption transcript for any video by URL or video ID, with no API key required.

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

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