{"uid":"cap_5zmVj3X_J3500NeEnvjoW","slug":"federal-register-search-api-d4c7cf7a","name":"Federal Register Search API","description":"Public data and utility APIs paid per call in USDC on Base (x402). No accounts, no API keys. 174 routes: crypto/equity data, onchain reads, DNS/email/security intel, geo/weather, x402 payment diagnostics, dev utilities and more.","url":"https://anibalb.duckdns.org/x402/federal-register?utm_source=zero.xyz","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"},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"n":3,"count":6225,"query":"bankruptcy","results":[{"type":"Rule","title":"...","agency":"...","abstract":"...","citation":"88 FR 12345","publication_date":"2026-10-01"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_5KkDP2X4LyOIF5g3P0Gsb","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Search and retrieve U.S. Federal Register documents including rules, notices, and proposed rules, filtered by keyword query","exampleAgentPrompt":"Search the Federal Register for all rules and notices related to 'stablecoin' and give me the top results with their agency names, abstracts, and citation numbers.","exampleUseCases":[{"title":"Regulatory compliance research","prompt":"Find me the latest Federal Register rules and notices about cryptocurrency regulation — I need the titles, agencies, and FR citation numbers so I can check what's been published recently."},{"title":"Legal research on bankruptcy rules","prompt":"Search the Federal Register for documents about bankruptcy — I want the most recent rules with their abstracts and publication dates for a legal brief I'm putting together."},{"title":"Environmental policy monitoring","prompt":"Pull up Federal Register entries related to 'clean air' so I can see which agencies have published rules or proposed rules on that topic and what their FR citations are."}],"resultDescription":"Returns a JSON object with the total count of matching documents, the number returned, the search query used, and an array of result objects each containing document type, title, agency name, abstract, Federal Register citation (e.g. '88 FR 12345'), and publication date.","failureModes":["Missing or empty query parameter returns error or empty results","Query too broad may return thousands of results with limited pagination","Federal Register API downtime causes upstream failure","No results found for highly specific or misspelled queries","Rate limiting or payment failure if USDC balance insufficient"],"whenToPreferThis":"Use this endpoint when you need to search U.S. Federal Register documents by keyword to find rules, proposed rules, or notices from federal agencies. Prefer this over general web search when you need structured regulatory data with official FR citations, agency attribution, and publication dates — especially for legal research, compliance monitoring, or policy analysis.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:40:23.953Z","isFirstParty":false,"canonicalSlug":"federal-register-search-api-d4c7cf7a"}