Pirate Ship doesn't offer an API.

Instead, we're focused on making shipping cheap & fun. Our goal is to remove all the technical stuff from shipping... we don't think it should be necessary to be a geek (like us) to ship a package!

If you're just trying to connect your eCommerce platform, take a look at the integrations Pirate Ship currently has, or maybe our flexible spreadsheet uploading (and tracking data exporting) can solve your need 😉