Transparency log · MCP tool definitions
Your AI client trusts the tool descriptions an MCP server sends it — and a server can change them after you approved it. HISTOR keeps a public, signed record of what every remote MCP server in the official registry advertised, and tells you the day it changed.
Remote endpoints: it lists tools and never calls one. Registry packages: bounded canary calls run inside the isolated sandbox. It never says a server is safe — it tells you what was said, and when.
WebGL is unavailable here. The picture is the log itself: each label is a leaf, leaf hashes climb a Merkle tree, and a signed tree head seals the root.
What HISTOR is for
When you connect an MCP server, its tool descriptions go straight to the model as instructions. A server can pass your review with harmless descriptions and change them next week — one added sentence is all a prompt injection needs, and most clients never ask you again.
Every day HISTOR reads what each remote (streamable-HTTP) endpoint in the official MCP registry advertises, fingerprints it, signs what it saw and appends it to a log that can only grow. When a server's definitions change, the change gets a date and a diff.
Look up any server before you trust it. Paste what your client received and learn whether everyone else sees the same thing. Follow changes in a feed, or put a badge in your README. Every answer is signed, so you can verify it instead of believing it.
io.github.bck-stack/sitecheck-company-records · https://api.companyrecords-api.workers.dev/mcp?ref=registry
120 pay-per-call agent tools: company registry, government, legal and B2B data tools. x402
b2b_ada_find_a_dentist — American Dental Association member dentists near a US ZIP code, from ADA Find-a-Dentist: dentist name, specialties (general practice, orthodontics, endodontics…), practice name, practice address and the ADA profile link, closest first (up to 100 per search). ADA members only; not every licensed dentist is listed. Price: $0.01 in USDC per successful call, paid with x402 (Base, Solana or Arc); faile …b2b_angies_list — Angi (Angie's List) top-rated pros for a service in a US city: business name, rating, review count, recommend rate, sub-ratings (quality, value, punctuality...), years in business, city/state/ZIP, service area, emergency/free-estimate/warranty/veteran flags, payment methods, services offered, a top review and the Angi profile link, plus the city's overall rating for the service. From angi.com's pu …b2b_apis_guru_openapi_directory — APIs.guru open directory of public API descriptions (OpenAPI specs): finds API providers by domain name (e.g. stripe, 1forge, googleapis) and returns each of their APIs with title, preferred version, description, categories, the OpenAPI spec URL and dates. Open-source catalogue of published specs, not a list of companies. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or A …b2b_bbb — Better Business Bureau search (bbb.org public search JSON): finds businesses by name and returns city, state, category, BBB rating, membership flag and profile URL. Public listings only; no complaint details. Respect BBB terms before reselling. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_benchmark_international — Recent M&A deals closed by Benchmark International, the mid-market sell-side adviser: target company, acquirer, deal summary (stake, location, sector as written) and announcement link, newest first, optionally filtered by a keyword (company, country, sector). Only announced completed transactions; confidential live mandates are not public. Price: $0.002 in USDC per successful call, paid with x402 …b2b_bizquest — Businesses for sale on BizQuest: listing title, short description, asking price when published, location text, image and listing URL, from the public search pages (all listings, or a US state). Financials beyond what the search page shows are not included. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_bolagsverket_sweden_companies — Swedish company register record by 10-digit organisation number (organisationsnummer) from Bolagsverket's and SCB's free weekly bulk files (EU high-value datasets): registered names, legal form, registration date, deregistration date and reason, ongoing liquidation or bankruptcy, business description, postal address, SNI industry codes and SCB status. About 2.2 million companies and associations; …b2b_booksy — Beauty, barber and wellness businesses listed on Booksy (US) for a category and region: name, address, coordinates, rating and review count, website/Instagram/Facebook, Booksy Pay, promoted flag and the first listed services with price and duration. Returns the first 20 results of Booksy's own search page plus the total count. regionId is the number in a Booksy search URL (e.g. 18229 = Chicago); w …b2b_brreg_norway_companies — Norway Business Register (Brønnøysund open API): searches companies by name and returns organisation number, legal form, industry code, employee count, registered address and registration status. Public open data, no key. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_census_business_builder — US Census County Business Patterns by state (latest year published, all legal forms): number of establishments, paid employees, first-quarter and annual payroll for a state FIPS code, for all industries or one NAICS code (2 to 6 digits). Official US Census Bureau data from its bulk state file. Aggregate counts only, no company names. Price: $0.002 in USDC per successful call, paid with x402 (Base, …b2b_chicago_business_licenses — City of Chicago current active business licenses: searches by legal or trade name and returns license type, business activity, address, ward, and license dates. Public open data (Socrata); licence rows only, no ownership or credit data. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_clio_app_directory — Clio App Directory (integrations for Clio legal practice-management software), one page of 9: app slug, name, one-line description, listed price (as shown, e.g. $50/month or Free), logo and app page link, plus the total page count. From clio.com/app-directory via a residential proxy. Price: $0.01 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_clutch_reviews — Clutch.co top B2B service providers in a category (web-developers, app-developers, agencies/seo, it-services...): name, rating and review count, verification badge, minimum project size, hourly rate, employee range, location, phone, service mix, sponsored flag and profile link; up to about 80 per page (pages 1-10). From clutch.co's public directory pages via a rendering residential proxy. Price: $ …b2b_cslb_california — California licensed contractors from the CSLB (Contractors State License Board) public Data Portal for one license classification (e.g. B, C-10 Electrical, C-36 Plumbing), optionally one county: license number, business name and type, address, phone, county, issue/expiration dates, classifications and status; county lists add bond and workers' comp insurer. Filter by city; paged. Price: $0.002 in …b2b_doabooks_directory_open_access — Peer-reviewed open access books from DOAB, the Directory of Open Access Books: keyword search returning title, authors/editors, publication date, abstract and the DOAB record link (with handle), plus the total number of matches. Paged, newest index first by relevance. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_doximity — US clinician data from Doximity's public directory. By profile (slug or doximity.com/pub URL): name, credentials, specialty, practice address with coordinates, phone, fax, education and training, board certifications, awards and hospital affiliations when listed. By location (state or state/city, e.g. north-carolina/raleigh): an alphabetical page of 50 clinicians with name, credentials and slug, p …b2b_euronext_equities — Euronext listed equities (daily list from live.euronext.com): lists or searches shares on one Euronext market by MIC code (e.g. XAMS Amsterdam, XPAR Paris) and returns name, ISIN, ticker, currency, last close, volume and turnover. End-of-day data from the last trading day; not real-time. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_finland_ytj_companies — Finland YTJ business register (PRH open data): searches companies by name and returns business ID, registration date, company form, current name and address. Public open data; no financial or credit information. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_france_bodacc_gazette — France BODACC commercial announcements (official gazette open data): latest notices, optionally filtered by text, with publication date, court, company register number and the notice URL. Public open data; announcements only, no credit score. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_g2_software_categories — G2 software categories: name, slug and G2 URL for about 2,000 categories from G2's public category directory, optionally filtered by a word (e.g. crm, security). Product lists, ratings and reviews inside each category are not included. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_goodfirms_companies — IT service companies ranked on GoodFirms: for a category (software development, web design, digital marketing, app development; software development also by country) the ranked list with name, hourly rate band, location, phone, rating, review count and a recent review; or one company's dossier (founding year, website, offices, sales contacts, services, rating and recent reviews) by its GoodFirms s …b2b_google_maps — Google Places text search: finds businesses by text (e.g. 'plumber Austin TX') and returns name, address, coordinates, place category, business status, Google place ID and Maps link. Uses the operator's Google Maps Platform key; Google's terms apply. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_gsa_elibrary — US federal GSA schedule contractor dossier from GSA's official CALC+ API: the contractor's GSA contracts (contract number, schedule, SINs, start and end dates, small-business status), its awarded labor categories with hourly ceiling prices, and price statistics (min, median, average, max, percentiles) plus education, experience and worksite mix. Search by contractor name or a service keyword. Rate …b2b_healthline_medical_providers_directory — US doctors by specialty and city from Healthline FindCare: physician name with credentials, practice address, phone, NPI number (from the profile id), photo and profile link, as listed on the city page (up to ~60). Specialty uses Healthline's slug (cardiology, dermatology, family-medicine, orthopedic-surgery, pediatrics…). Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or …b2b_hyperliquid_leaderboard — Hyperliquid public trader leaderboard: top accounts ranked by PnL for a chosen window (day, week, month, allTime), with account value, ROI and traded volume. Public on-chain stats; addresses only, no names. The source file is large, so the first call after a cache miss is slow. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_iceland_skatturinn_companies — Icelandic company register (Fyrirtækjaskrá, Skatturinn): search companies by name (kennitala/ID number, name, address), or look up one company by its 10-digit kennitala for the full public record: name, registration date, other names, postal and legal address, municipality, legal form (ehf., hf., sf....), officers listed by the register, ÍSAT industry classification, and VAT numbers with registrat …b2b_importyeti — ImportYeti US import records: searches companies by name and returns shipment counts, most recent shipment date, address and profile URL from ImportYeti's public search. Company search only, not individual bills of lading. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_indiamart — Indian wholesale suppliers and manufacturers on IndiaMART for a product keyword: supplier name, state, years exporting, nature of business, year established, verification badges (verified exporter, TrustSEAL, GST, IEC), rating and review count, export markets, product name, category, listed price and unit, minimum order and key specifications, with catalogue and product links. First result page (a …b2b_ireland_cro_companies — Irish companies from the Companies Registration Office (CRO) official open data (CC BY 4.0, updated daily): search by name or look up a company number; returns company number and name, status, legal type, registration and dissolution dates, last annual return and accounts dates, next annual return date, registered address, Eircode and principal object code. Price: $0.002 in USDC per successful cal …b2b_israel_companies_registrar — Israel Companies Registrar (Ministry of Justice open data, data.gov.il): searches companies by Hebrew or English name and returns company number, type, status, incorporation date, registered city and street. Public register extract; no financial data, no officers. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_jobvite_jobs — Open jobs of a company whose careers site runs on Jobvite (jobs.jobvite.com/<company>): every open position with department, title, location (or number of locations) and link, plus counts per department as a hiring signal; with a job id, that posting's details (date posted, employment type, department, locations, salary range when published, description text). Price: $0.002 in USDC per successful …b2b_lead_formatter — Lead formatter: cleans a list of contact records you supply (name, company, email, phone, website) into one consistent shape: trims spaces, fixes casing of names, lowercases emails and domains, keeps digits of phone numbers, and flags invalid emails. It adds no outside data. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_linkedin_company_profiles — Public LinkedIn company page facts: name, description, headquarters address, employee count band, website links and logo, from the schema.org data LinkedIn publishes on the public company page (no login). Posts, followers and people are not included. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_listennotes_podcasters_directory — Listen Notes podcast search: finds podcasts by keyword and returns title, publisher, episode count, first and latest episode dates, update frequency, genre IDs, explicit flag, sponsor and guest-interview flags, website and Listen Notes link. Podcast metadata only. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_macvendors_lookup — MAC address vendor lookup (IEEE OUI registry via macvendors.com): returns the registered hardware vendor for a MAC address or OUI prefix. Public free API; vendor name only, no device data. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_manta — Manta US small-business directory search by keyword and city/state: business id, name, street, city and state, phone, website, claimed flag, description and Manta profile link, about 10 per page. From manta.com via a residential proxy. Price: $0.01 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_ncarb_architects_directory — NCARB-certified architects (US national certificate holders, all licensed in at least one US jurisdiction) from NCARB's official Certificate Lookup: name, city, state/province and country, filtered by last name, first name, city, US state/Canadian province or country, with the total match count. To confirm a specific license number use the state board roster. Price: $0.002 in USDC per successful c …b2b_ny_business_entity — New York Department of State active corporations: searches by entity name and returns entity type, county, initial filing date and service-of-process address. Public open data (Socrata), updated monthly; not a credit or ownership report. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_nyc_business_licenses — NYC Department of Consumer and Worker Protection license list: searches by business name and returns license number, category, status, expiry date and address (borough, zip). Public open data (Socrata); license rows only. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_nyc_certified_business — NYC Small Business Services certified business list (NYC Open Data): searches vendors by formal or trade name and returns certification, NAICS industry, city, website and renewal date. Public open data; owner contact and personal fields are excluded on purpose. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_nyse_listings_directory — NYSE-listed symbols from the public Nasdaq Trader symbol directory (otherlisted file): searches by ticker or security name and returns symbol, security name, exchange code, ETF flag and round lot size. Symbol directory only, no prices or company profiles. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_nz_companies_register — New Zealand Companies Register search (official NZ Companies Office): company name, company number, NZBN, status (Registered, Removed…), entity type, registered address and incorporation date for a name keyword, with the total match count and paging (15 per page). Data comes from the public register search page. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); faile …b2b_openfda_drug_ndc — openFDA National Drug Code directory: searches US drug listings by brand or generic name and returns labeler (company), NDC code, dosage form, route, marketing start date and active ingredients. Public FDA data; not medical advice. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_openllm_leaderboard — Open LLM Leaderboard v2 (Hugging Face, archived March 2025): finds open-source language models by name across all 4,576 leaderboard rows and returns average score, IFEval, BBH, MATH Lvl 5, GPQA, MUSR and MMLU-PRO scores, parameter count, likes, license and hub URL, best average first. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_payscale_company_benefits — US employer pay and benefits from PayScale: most reported benefits with counts, retirement and health benefit types, salary, bonus, profit-sharing, commission and hourly percentiles (10-90) with sample sizes, job satisfaction, stress and gender split vs comparable employers, top locations and company facts. Employer by PayScale key (e.g. Microsoft_Corp) or name. Price: $0.002 in USDC per successfu …b2b_pgatour_leaderboard — PGA Tour current and upcoming events from ESPN's public scoreboard: tournament name, dates, status, and the player leaderboard when a tournament is running (empty list before the first round). Public ESPN data, not an official PGA Tour feed. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_seek_company_reviews — Employer reviews from SEEK, the main job site of Australia and New Zealand: company name, industry, size, website and HQ, overall rating with sub-ratings (benefits, career, work-life balance, management, diversity), star distribution, % who recommend, salary perception, and the 30 newest reviews (title, pros, cons, job title, location, tenure, ratings, recommended, date). company = the SEEK compan …b2b_similarweb — Similarweb traffic overview for a domain (public page data, last full month): global, country and category rank, monthly visits and change, 3-month trend, bounce rate, pages per visit, visit duration, traffic sources, top countries, age and gender split, organic vs paid search, top keywords and social networks, similar sites and company facts. From similarweb.com via a stealth proxy. Price: $0.05 …b2b_skip_trace — Owner of record for a New York City property: owner name, tax lot (BBL), building class, land use, year built, floors, units, lot and building area, assessed value and zoning, from NYC's public PLUTO tax-lot file. NYC only. Public property records only: no phone, e-mail or people-search data. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not char …b2b_slovakia_rpo_companies — Slovakia RPO register (Statistical Office open API): looks up a legal entity by its 8-digit company ID (IČO) and returns registered names, establishment date, registry court and address. Search by name is not supported by the API; open data under CC BY 4.0. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_spain_empresia — Spanish company dossier from Empresia (data from the Mercantile Registry gazette BORME): status, CIF tax id, business purpose and CNAE code, share capital, sales band, registry, last filed accounts year, employees, board type, auditor, phones, websites and the current directors/officers with appointment dates. Search by company name or open a company by its Empresia slug; other matches are listed. …b2b_techstars_portfolio — Techstars portfolio companies (5,600+): search by keyword and filter by region, country, first program year, exited or unicorn status. Each company: name, one-line description, website, city, state, country, region, industry verticals, Techstars programs attended, first session year, accelerator/network flags, exit and $1B+ flags, Crunchbase link and logo; plus the number of matches. Price: $0.002 …b2b_texas_sos_business — Texas active franchise taxpayers (Comptroller open data, data.texas.gov): searches by taxpayer name and returns SOS file number, charter date, status code, organisation type and address. Public open data; not a live SOS filing search and no officer data. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_thomasnet — US and Canadian industrial suppliers from Thomasnet for a product or service term (valves, CNC machining...): top 25 suppliers with ID, name, type (manufacturer, distributor...), tier, verified flag, address with coordinates, phone, website, sales and employee bands, year founded, description, capabilities, brands and products, plus the total match count. Optional state filter on those 25. Price: …b2b_trustpilot_reviews — Trustpilot reviews for a company website: business name, TrustScore, star rating, total reviews and reviews in the last 12 months, categories, plus 20 reviews per page (page 1 to 10, newest first; optional star filter) with rating, title, text, dates, reviewer name, country and review count, verification level and the company's reply. From trustpilot.com's public review pages via a rendering resid …b2b_webmd_healthcare_provider_directory — WebMD Care doctor directory for a specialty in a US city: name, credentials, NPI, specialty, gender, graduation year, patient rating and review count, a review quote, nearest office (address, medical group, phone, distance) and WebMD profile link; 60 per page, plus the total count. From doctor.webmd.com's public search pages via a residential proxy. Price: $0.002 in USDC per successful call, paid …b2b_welcometothejungle_companies — Employer profiles from Welcome to the Jungle (about 17,000 companies, mostly France and Europe): name, sectors, size band and employee count, offices (city, region, country, headquarters flag), open jobs count, tech stack, labels/certifications, short description, accepts spontaneous applications, logo and profile URL; plus the number of matches. Search by keyword, filter by office country and hir …b2b_y_combinator — Y Combinator startup directory: searches companies by name and returns batch, status, industry, team size, one-liner, website and YC profile URL. Community-maintained open mirror of YC's public company list; not an official YC API. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.b2b_yellowpages — Yellow Pages (US) business listings for a search term and location: name, phone, street address, city/state/ZIP, categories, star rating and review count (where shown), years in business, website and YP listing link. Up to 30 per page, page 1 to 10. From yellowpages.com's public search through a residential proxy. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); fai …gov_anac_italy_procurement — Italian public procurement datasets from ANAC open data (dati.anticorruzione.it, CKAN): dataset title, publisher, licence, last modified date, number of resources and dataset link, for a search term. Catalogue metadata only, not the tender records. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_anvisa_brazil_medicines — Brazil ANVISA registered medicines (official open-data file): search by product name, active ingredient or registration number. Returns product, active ingredient, regulatory category (Novo, Genérico, Similar...), registration number and expiry, process number, therapeutic class, holder company with CNPJ, and status (Ativo/Inativo). Source file is updated weekly; the first call after a cache refre …gov_ares_czech — Czech business register (ARES) record by IČO (8-digit company number): business name, VAT ID (DIČ), legal form code, registered address, incorporation and last-update dates, tax office code. Public ARES data; codes are raw ARES codes. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_australia_data_gov_au — Australian government open datasets from data.gov.au (CKAN API): title, publisher, licence, last modified date, number of resources and dataset link, for a search term. Catalogue metadata only, not the data files. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_business_bankruptcy_filings — US federal bankruptcy dockets matching your text from CourtListener (Free Law Project): case name, docket number, court, chapter, filing and termination dates, judge and a CourtListener docket link. Search results only; not every PACER filing and not a complete bankruptcy registry. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_california_dre_real_estate — California DRE real estate licence lookup (official public licence records): by licence ID get licence type, name, mailing address, status, expiration and issue dates, former names, responsible broker, disciplinary/public comments; or search by licensee/company name (optional city) for matching licence IDs, names, licence types and cities. Price: $0.002 in USDC per successful call, paid with x402 …gov_canada_open_data — Canadian federal open datasets from open.canada.ca (CKAN API): title, publisher, licence, last modified date, number of resources and dataset link, for a search term. Catalogue metadata only, not the data files. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_canadabuys_tenders — Open Government of Canada tender notices from the CanadaBuys open data CSV: reference number, English title, publication date, closing date, status, notice type, procurement method and category. Optional word filter on the English title. Open notices only (the file is refreshed by CanadaBuys). Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not cha …gov_caselaw_access — Caselaw Access Project volume metadata for one reporter (for example a2d = Atlantic Reporter, 2nd series): volume number, publisher, year, jurisdictions and volume ID. Returns volume metadata only; case texts are not included. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_clinicaltrials — ClinicalTrials.gov studies matching a condition, drug or keyword: NCT number, title, overall status, start date, conditions, lead sponsor and study page link. Registry records only; results are as registered by sponsors. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_court_records_ecourt_india — Indian High Court judgments and final orders from the eCourts judgment portal (via the public 'Indian High Court Judgments' AWS Open Data mirror, 25 High Courts, 1950-2026): case title, judges, CNR, registration and decision dates, disposal nature, opening text and PDF link. List a court's judgments for a decision year (CNR order, paged) or look up a CNR. Mirror is updated about quarterly (CC-BY-4 …gov_data_gov — Search the Data.gov catalog (300,000+ US federal, state and local open datasets): title, publisher and organisation, description, keywords, themes, access level, last modified and issued dates, whether a download exists, and each distribution (title, format/media type, download or access URL), plus the dataset page URL. Results come in relevance order; pass the returned next cursor to get the foll …gov_data_gov_uk — UK government open datasets from the data.gov.uk catalogue (CKAN API): title, publisher, licence, last modified date, number of resources and dataset link, for a search term. Catalogue metadata only, not the data files themselves. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_dati_gov_it_italy_open_data — Italian open government datasets from dati.gov.it (CKAN API): title, publisher, licence, last modified date, number of resources and dataset link, for a search term. Catalogue metadata only. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_delaware_business_search — Businesses licensed to do business in Delaware, from the Division of Revenue's official open data (daily): business and trade name, license category, license number, current validity period and address with coordinates. Search by name, trade name, license number, category or city. Corporate entity filings (Division of Corporations) are not included. Price: $0.002 in USDC per successful call, paid …gov_dibbs_rfq — Defense Logistics Agency (DLA) RFQs, solicitations, pre-solicitations, sources-sought and award notices as published on SAM.gov Contract Opportunities (official US federal source), searchable by keyword, NSN or part number. Returns solicitation number, type, title, office, dates, short description and SAM.gov link. Small-value RFQs that DLA posts only inside DIBBS (behind a DoD consent banner) are …gov_dupont_registry — Luxury and exotic cars for sale on duPont REGISTRY (US/Canada dealer inventory): newest listings for a brand or brand+model with year, make, model, price (USD, null = call for price), mileage, VIN, stock no., condition, colours, dealer and city, listing link, plus the total matching count and per-model counts. First result page only (about 17 newest listings). Commercial marketplace data, not an o …gov_energy_gov — US Department of Energy public dataset catalogue (energy.gov Public Data Listing, DCAT data.json): dataset title, publisher, last modified date, access level, landing page and number of downloadable distributions, filtered by a word in the title or description. Catalogue metadata only. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_epa_aqs_air_quality — US EPA Air Quality System certified monitor data for a county: daily values per monitor (mean, daily max, AQI, method, site) or annual summaries (mean, 98th/99th percentiles, exceedance counts) for PM2.5, PM10, ozone, NO2, SO2, CO or lead. County by name or FIPS code. Official quality-assured data, published about six months after measurement. Price: $0.002 in USDC per successful call, paid with x …gov_eu_compliance_pack — EU counterparty check in one call: screens a person or company name against the official EU Consolidated Financial Sanctions List (all aliases, word match, accents ignored) and, with a VAT number, validates it in VIES (valid flag, registered name and address where shared). Returns matched entities with EU reference, programme, regulation and link. A hit is a lead to review, not a legal determinati …gov_eu_funding_tenders — EU Funding & Tenders Portal search results (SEDIA) for a keyword: reference, short title (summary), database, language and portal link. Public portal search; the portal indexes calls and tenders. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_faa_aircraft_registry — US FAA aircraft registry record for an N-number: serial, status, manufacturer, model, year, certificate and expiry dates, registered owner and address. Public FAA inquiry page; the FAA says the data is not for airworthiness decisions. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_fda_warning_letters — Latest FDA warning letters from the FDA listing page: company, issuing FDA center or program, subject (violation category) and issue date, with a link to each letter. First listing page only; no full history and no letter text. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_findlaw — Lawyers and law firms listed in the FindLaw directory for a practice area in a US city: name, firm or attorney, phone, street address, website, rating and review count, firm of an attorney, profile link. Reads the structured data on FindLaw's public city page (first page only, ~20-40 of totalListed, in FindLaw order incl. sponsored placement). A directory listing is not proof of a bar licence; che …gov_finland_prh — Finnish company register (PRH / YTJ) record by Business ID: registration date, status code, company form, main business line, names with dates and addresses. Registry data as published by PRH; codes are passed through raw. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_fmcsa_carrier_safety — FMCSA carrier census record by USDOT number from the public FMCSA Company Census File (data.transportation.gov): legal name, address, power units, drivers, status code and registration dates. Census file, not live inspection or crash data. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_fmcsa_household_goods_complaints — US interstate movers and their household-goods complaint history from FMCSA's Protect Your Move search. By USDOT or MC number: name, numbers, address, phone, fleet, safety rating, authority types and complaints per year for the last four years by category (estimates, hostage goods, loss/damage, insurance...). By name or state: matching registered movers with location, fleet size and USDOT id. Pric …gov_fueleconomy_gov — US EPA fuel economy ratings from FuelEconomy.gov for a model year, make and model: each matching vehicle's EPA combined, city and highway MPG, fuel type, drive type and CO2 tailpipe grams per mile. Up to 3 vehicles per call. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_global_court_records_aggregator — Court records from two official open sources in one answer: US federal dockets matching a term (CourtListener) and Indian Supreme Court judgment metadata for a year (AWS Open Data). Each item names its source. Not a full court index of any country. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_global_tender_funding_watch — Latest public tender and contract items from three official sources in one answer: EU TED notices (last 30 days, buyer country optional), UK Find a Tender notices, and US federal contract awards (USAspending, last 30 days). Each item names its source. Not a complete list of any one market. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged …gov_govdata_germany — German open government datasets from GovData.de (CKAN API): title, publisher, licence, last modified date, number of resources and dataset link, for a search term. Catalogue metadata only, not the data files. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_govdeals — Live US government surplus auctions on GovDeals for a keyword: asset ID, title, make, model, model year, category, current bid (USD), reserve-not-met flag, auction start and end (UTC and as shown), time remaining, seller agency, city, state and ZIP, photo and asset URL; plus the total number of matching auctions. Sort by relevance, ending soonest, newest or bid. Price: $0.002 in USDC per successfu …gov_government_contract_awards — US federal contract awards from USAspending.gov for a recipient name over the last 365 days: award ID, recipient, amount in USD, awarding agency and start date. Contracts only (not grants or loans); covers awards reported to USAspending. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_governmentbids — Open US/Canadian government bid solicitations (state, local, federal) listed on BidNet Direct's free public search: title, location, publication and closing dates, notice id and link. Keyword search, newest first, 25 per page. Only the public teaser fields are returned; full bid documents on BidNet Direct need a (free or paid) vendor account and are not included. Price: $0.002 in USDC per successf …gov_govtrack_congress — US Congress bill status from the official GPO GovInfo BILLSTATUS bulk XML (the GovTrack API it replaces has closed): title, sponsor, introduced date, latest action and official congress.gov link for one bill by congress, bill type and number. Covers congresses with BILLSTATUS files (119 at test time). Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are …gov_grants_gov — US federal grant opportunities from Grants.gov (search2 API): opportunity number, title, funding agency, open and close dates, status and CFDA numbers, for a keyword. Opportunity listings only, not award decisions. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_harris_county_court_records — Harris County (Houston, TX) District Court new filings from the District Clerk's free daily datasets. Civil: cases filed on a day (last 7 days) with case number, court, case type, status and parties (role, name, address). Criminal: latest day's filings with case number, court, offense, bail, next setting, defendant name, SPN, sex, race, city/ZIP (no birth date or street) and attorney. Price: $0.00 …gov_healthcare_gov — ACA Health Insurance Marketplace (HealthCare.gov) plans for a US ZIP code from CMS's QHP Landscape data: plan ID and name, issuer, metal level, plan type, monthly premium before subsidies for the nearest published age (0-14, 18, 21, 27, 30, 40, 50, 60) and a couple, deductible, out-of-pocket maximum, copays, silver cost-sharing reductions, phone and plan document links, cheapest first. Federal-pla …gov_healthdata — HealthData.gov (HHS) dataset catalogue: dataset ID, name, short description, display type, last rows update and dataset link, for a search term. Catalogue metadata only; some datasets are non-tabular and have no row API. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_india_supreme_court — Indian Supreme Court judgments from the AWS Open Data dataset (CC-BY-4.0): for a judgment year, returns judgment IDs, neutral citation and the scrape date of up to 3 metadata records. Metadata only; full judgment text is not included and case titles are not in the metadata fields used. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.gov_ip_australia_trademarks — IP Australia trade mark records by trade mark number from the IPGOD open data table on data.gov.au (2017 edition, marked superseded): status, live or dead, mark type, lodgement and registration dates, Madrid indicator. Applicant names are not in this table. Price: $0.002 in USDC per successful call, paid with x402 (Base, Solana or Arc); failed calls are not charged.The signed observations, every earlier tool set and a diff of each change: this page with scripts on, or /api/v1/servers/536400e6e86b7e73.
Read → digest → label → append → sign → compare
Six steps, every one of them checkable by someone who does not trust HISTOR. The only thing you have to take on faith is that the observation happened when the label says it did — and the log makes it impossible to change that story afterwards.
Remote endpoints in the official MCP registry: initialize, then tools/list, drained across every page; no tool is called, and private addresses are refused before the connection opens. npm and PyPI packages: installed and started in the sandbox described below, with no route out.
The tool set is reduced to name, description, input and output schema, sorted by UTF-16 code units and hashed over its RFC 8785 canonical form. Anyone holding the same tools gets the same digest — which is what makes a comparison possible.
Four MTL/1 methods, one signed AWR/2 document each: what was observed, what the WARDEN pattern set matched, whether the definitions changed since the last label, and whether the name is on a threat list. No score, ever.
Every label becomes a leaf of an RFC 9162 Merkle tree: leaf hash = SHA-256(0x00 ‖ JCS(label)). The label you download is the leaf input, so you can recompute its hash yourself.
After each crawl HISTOR signs a tree head: the size and the root. Keep yesterday's head; ask for a consistency proof to today's; if anything was removed or rewritten, the proof fails.
Each day a continuity label compares the new digest with the last one. Equal: "unchanged since". Different: a change, with the date and a per-tool diff. A client that checks what it received adds the view no crawler has.
Where an npm or PyPI package is run
A package observation is true for these conditions, and no others. Every package page names the exact image it ran in and any configuration it was given.
Linux x86_64, inside gVisor (runsc): the package talks to a kernel written for sandboxing, not to the host's. An unprivileged user, no capabilities, a read-only root.
npm packages in histor-node:22, PyPI packages in histor-python:3.12: the official node:22-bookworm-slim and python:3.12-slim images plus bash, git, Python 3 or Node 22 and a Java 21 runtime — never Docker — built when a sandbox host is installed. A package whose Requires-Python excludes 3.12 runs on histor-python:3.13 or 3.14; one that requires a newer Node runs again on histor-node:24. The exact image a package ran in is on its page.
npm with --ignore-scripts, then the install scripts in a traced stage of their own. PyPI: wheels only — a package that ships only source is reported, never built.
No route out. Every name the package looks up resolves to HISTOR's own traps, which record what was sent and forward nothing. A server that needs the internet to start shows that here.
None are real. Decoy credentials sit in HOME and a decoy .env in the working directory. A variable the package says it needs gets a placeholder; where the placeholder was sent is recorded.
512 MB of memory, one CPU, 64 MB of /tmp. 360 s to install, 150 s to start and answer; up to 15 tools called once each with canary arguments, 8 s per call.
Only names: required variables its registry entry declares or that it printed when it exited, and a start argument such as serve when its usage text offers one. Never a value from anyone else.
The profile HISTOR implements forbids the words safe, secure, audited, certified, approved and trusted. Here is why, in the terms of what the log can and cannot show.
A pattern match is a reason to read a definition, not a finding. Three of the four methods can never return fail. There is no score to rank by, because no score HISTOR could compute would mean what a reader takes it to mean.
Labels are about advertised text. A remote endpoint's source is never read and its tools are never invoked; a package runs only in the sandbox, against nothing real. A server can keep identical definitions and behave differently for real users; the log cannot see that, and says so inside every label.
A version bump changes definitions too. A change is shown as a date and a diff, in amber, never red. What you do with it is yours: re-read, re-approve, or pin the old digest.
An npm or PyPI server is observed under the test conditions above: Linux, no internet, placeholder keys. One that needs Windows, a real account or the network may show fewer tools or none; its page says why it exited.
Today one party runs the log. A second observer on another network is the next step, and any AIMarket hub can run one. Until then, what the key proves is who said it — not that it is true.
Endpoints that require authentication answer 401 to everyone without a key, including HISTOR. They are counted and listed as not observed, never dropped from the numbers.
For clients, registries and server authors
Before your agent trusts a server, send the tools it received. The answer is signed by the log's did:key and names the tree head it was given under.
curl -sS https://histor.modelmarket.dev/api/v1/check \
-H 'Content-Type: application/json' \
-d '{"endpoint":"https://example.com/mcp","tools":[ …tools/list result… ],"contribute":true}'
# -> {"type":"histor.check/v1","match":"same"|"different"|"previously-observed"|…,
# "observed":{"unchangedSince":"…","changes":0}, "patternScan":{…}, "signature":{…}}
# README badge for your server
[](https://histor.modelmarket.dev/s/<id>)
# Atom feed of every observed change
https://histor.modelmarket.dev/feed.xml
No. The server list is the log's index: every remote endpoint in the official MCP registry, with what HISTOR could observe about it. Nothing here is for sale and nothing is ranked by quality.
No, and it never will. It tells you what a server advertised, whether that changed, and which published patterns matched the text. Whether to trust the server is your decision — HISTOR makes sure you decide on the same facts as everyone else.
Most remote MCP endpoints require a login (they answer 401 to anyone without a key), some use the legacy SSE transport or need per-user values in the URL, and some are simply down. They stay on the list with the reason, so the numbers never hide them.
Open the Check tab, paste the server's endpoint and the tools/list result your client received, and press Check. You get back, signed, whether HISTOR observed the same definitions — or different ones, or an older set.
Find your endpoint on the Servers tab, open it, and copy the Markdown snippet under the facts. The badge shows the date your definitions were pinned or last changed, and links to the full history.
You do not have to. Every label and every tree head is signed with one published key; the Log tab proves in your browser that the log only grew; and the command-line auditor does the same from any machine. What remains is that one operator runs it today — a second, independent observer is the next step.
Looking things up, the badges, the feed and /check are free. HISTOR also offers histor.check@v1 to the AIMarket Hub, so agents can reach it through the market.
Once a day: initialize, notifications/initialized and tools/list — never a tool call, never a redirect followed, at most two connections per host, from a User-Agent that starts with histor/. To be left out, open an issue on the histor repository with your endpoint or host; it is then listed as not observed (operator-opt-out), with the reason, rather than silently dropped. Labels already in the log stay: the log only grows.