x402 endpoint validator - checks a URL returns a well-formed 402 challenge with valid accepts per network

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Data breach catalogue from Have I Been Pwned filterable by name or recency - accounts affected, data exposed, passwords flag, dates and a summary

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Search the Human Phenotype Ontology for clinical signs and symptoms - HP id, name, definition and synonyms with a link to each term page

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Search Reactome biological pathways by topic - id, name, species and summary

Search the Protein Data Bank for 3D structures by free text - title, method, resolution and release date

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Protein-protein interaction partners from STRING for a gene symbol - combined confidence score and evidence from experiments, databases and text mining

Search 75,000+ public-domain books on Project Gutenberg by title or author

Refugee statistics by country (UNHCR) - refugees, asylum seekers, displaced and stateless people, with top host and origin countries

Protein search across UniProtKB by name, function or gene - accession, organism, length and review status

Newly discovered exoplanets (NASA Exoplanet Archive), newest first, with method, size, mass and orbit

How common a first name is in Brazil by decade of birth from the IBGE census - total people, peak decade and counts for each decade, for up to five names

Czech company register (ARES) lookup by IČO number or name - legal name, address, VAT ID, founding date, NACE activity codes, tax office and active status

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