TaxJar
TaxJar is a sales tax automation platform, now a Stripe company, providing APIs for real-time sales tax calculations, rooftop-level rate lookups, transaction recording, and automated filing across US states and international jurisdictions. The platform supports e-commerce businesses of all sizes with sub-20ms response times, 99.999% historical uptime, and AI-powered product tax classification. TaxJar handles nexus tracking, exemption certificate management, and AutoFile returns so merchants can stay compliant without manual effort. Official client libraries are available for Ruby, Python, PHP, Node.js, C#/.NET, Java, and Go.
APIs
TaxJar Sales Tax API
REST API for real-time sales tax calculation, rate lookups, tax category listing, transaction management (create, update, delete, list), customer exemption management, nexus reg...