Principle API
No API of any kind. Principle is a Mac-only prototyping app whose whole integration surface is file import from Figma and Sketch and export to HTML, video, GIF, or a Mac app. A long-requested JavaScript API for HTML exports has never shipped.
Frequently asked questions
Principle scores F on Supergood's API Report Card. No API of any kind. Principle is a Mac-only prototyping app whose whole integration surface is file import from Figma and Sketch and export to HTML, video, GIF, or a Mac app. A long-requested JavaScript API for HTML exports has never shipped.
Without a usable official API, teams fall back on manual exports, file drops, or one-off vendor integrations. The other option is an unofficial API layer like Supergood that automates the authenticated web app directly. Site terms may apply to any integration approach, and how they apply is a determination each team makes for itself.
Principle is a native macOS desktop application for designing animated and interactive user-interface prototypes.
Vertical: misc / horizontal creative tooling (not a Supergood vertical SaaS, not Legal, Healthcare, Real Estate, Compliance, Financial Services, Behavioral Health, Property Management, Fleet, Insurance, etc.). Timeline-based keyframe animation for UI elements (transform, opacity, color, blur, etc.) across multiple artboards.
Low and declining. Principle had a peak moment in 2016–2019 as the go-to Mac tool for high-fidelity UI motion prototypes, especially among iOS designers.
Principle stores and processes only local design IP on a designer's Mac. Specifically: `.prd` Principle document files containing layered artboards, components, animation timelines, drivers/events, and embedded raster/vector assets.
Principle is ~11 years old (initial release 2015, currently in the 6.4x version series). Architecturally it is a native macOS Cocoa/AppKit application built around a custom animation timeline and event/driver runtime.
No public REST/GraphQL API, no SDKs, no webhooks, no OAuth, there is no developer platform at all. Multi-year unanswered community request for a JavaScript API on the HTML export so prototypes could be embedded and externally driven. Full sourced list under Sources below.
Common alternatives include Figma (with native prototyping + Smart Animate), ProtoPie, Framer, Sketch (with native prototyping), Origami Studio (Meta), Rive. Graded alternatives appear under "More from the report card" below.
Supergood's grades measure one thing: can a customer's engineering team get their own data out programmatically? Supergood checks six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and rolls them into a letter grade. Supergood re-verifies grades, and they only move on evidence.
Not that we could find. As of August 2026 there is no official Principle MCP server in any public registry, and no maintained community server we're aware of. We re-verify this periodically — report an inaccuracy below if we missed one.
Not natively. Principle doesn't publish an MCP server, so MCP clients like Claude, Cursor, and Codex have nothing to connect to out of the box. If that changes, this page will reflect it.