Spline is a collaborative 3D design tool for building interactive scenes for websites and apps. It runs in the browser, and AI agents can build in the same file as your team.

Key features:

Model with primitives, booleans, sculpting, and AI 3D generation.
Add layered materials, lights, and post-processing.
Animate with states, keyframes, events, and physics.
Connect agents like Claude, ChatGPT, or Cursor through the Spline MCP to read and edit scenes.
Publish to the web or React, or export native views for iOS and Android apps.

Spline has a free plan with limited personal files and watermarked web exports. Paid plans are per seat each month: Hobby costs $12 billed annually or $15 monthly, Pro $25 or $30, and Max $60 or $70.