Below is the list of public API for books and business category. More information on documentation is available after visiting the link in Link Column.
| API | Description | Link | Auth |
| British National Bibliography | Books | http://bnb.data.bl.uk/ | |
| Crossref Metadata Search | Books & Articles Metadata | https://github.com/CrossRef/rest-api-doc | |
| Google Books | Books | https://developers.google.com/books/ | OAuth |
| LibGen | Library Genesis search engine | https://garbage.world/posts/libgen/ | |
| New York Times Books | Book reviews and The New York Times Best Sellers lists | https://developer.nytimes.com/docs/books-product/1/overview | apiKey |
| Open Library | Books, book covers and related data | https://openlibrary.org/developers/api | |
| Penguin Publishing | Books, book covers and related data | http://www.penguinrandomhouse.biz/webservices/rest/ | |
| Wolne Lektury | API for obtaining information about e-books available on the WolneLektury.pl website | https://wolnelektury.pl/api/ | |
| Charity Search | Non-profit charity data | http://charityapi.orghunter.com/ | apiKey |
| Clearbit Logo | Search for company logos and embed them in your projects | https://clearbit.com/docs#logo-api | apiKey |
| Domainsdb.info | Registered Domain Names Search | https://domainsdb.info/ | |
| Freelancer | Hire freelancers to get work done | https://developers.freelancer.com | OAuth |
| Gmail | Flexible, RESTful access to the user’s inbox | https://developers.google.com/gmail/api/ | OAuth |
| Google Analytics | Collect, configure and analyze your data to reach the right audience | https://developers.google.com/analytics/ | OAuth |
| mail.tm | Temporary Email Service | https://docs.mail.tm | |
| MailboxValidator | Validate email address to improve deliverability | https://www.mailboxvalidator.com/api-email-free | apiKey |
| mailgun | Email Service | https://www.mailgun.com/ | apiKey |
| markerapi | Trademark Search | http://www.markerapi.com/ | |
| ORB Intelligence | Company lookup | https://api.orb-intelligence.com/docs/ | apiKey |
| Smartsheet | Allows you to programmatically access and Smartsheet data and account information | https://smartsheet.redoc.ly/ | OAuth |
| SwiftKanban | Kanban software, Visualize Work, Increase Organizations Lead Time, Throughput & Productivity | https://www.digite.com/swiftkanban/ | apiKey |
| Trello | Boards, lists and cards to help you organize and prioritize your projects | https://developers.trello.com/ | OAuth |
Data credit for https://github.com/davemachado/public-api#get-random