Spline rebuilt its entire 3D editor. Then it handed the keys to Claude Code.
The New Stack Amanda Caswell
Spline rebuilt its 3D editor and let Claude Code edit live scenes through a local MCP server. That means agents can change the real project, not just spit out a mockup.
Based on reporting by The New Stack, Amanda Caswell — read the original for the full story.
Summary, retelling and take written by AI under human oversight; images are AI-generated illustrations. How we work · Report an error
Spline rolled out V2 on Thursday, and the big shift is simple: its rebuilt 3D editor can now be driven by external coding agents while the scene is still alive. The new MCP Server opens the door to Claude Code, Cursor, Codex, Google Antigravity and VS Code, all through a local connection bundled with the desktop app. Spline also ships its own AI agent in V2, which can build and edit a scene from a prompt.
The workflow is aimed at letting an agent work with the same live project a designer is already editing. If someone asks Claude Code to make a floating island, the request gets turned into structured MCP calls, routed to an open editor tab, and applied directly to the document. If there isn’t a suitable file open, Spline can create one. The result stays editable inside Spline, rather than being flattened into a static image or a dead mesh.
That matters most when the agent has to move between the 3D scene and the app interface. Spline V2 puts both the editor and Hana behind the same MCP connection, then handles the handoff itself: scene work goes to the 3D editor, interface changes go to Hana. In Hana, the agent can turn an existing component into an editable frame and push changes back into the application code using stable references on exported elements. But Hana only supports a subset of HTML and CSS centered on flexbox, so some complex code still has to be adapted instead of replaced outright.
Spline says changes made through its own AI agent behave like normal editor actions, showing up in undo history and syncing to everyone else in the file. The MCP server is tied to the desktop app on macOS and Windows, not the browser, and there’s no separate server package to install. It binds to 127.0.0.1, uses an origin allowlist, and lets developers choose which clients can connect. Prompts and scene data stay between the desktop app and the client, though any Spline AI generation still runs in the cloud. And while several agent sessions can connect to one editor, Spline does not explain how teams should review or attribute those individual changes before publishing a shared file.
My take — AI-written commentary, not fact-checked reporting
This is the right kind of AI integration: not a chatbot bolted onto the side, but an agent with its hands on the actual file. The catch is the usual one — once tools can edit production-grade creative work, “who changed what” stops being a nice-to-have and starts being the whole product. The industry keeps racing to give agents more keys; audit trails are moving at the speed of a polite shrug.
Read more about this at: The New Stack
