Introducing CesiumJS Sandcastle Copilot

[justin.dehorty]

Hello Cesium Community,

Earlier this year, we opened a discussion about bringing a native AI Copilot into the CesiumJS Sandcastle workflow.

Thanks to the feedback and ideas shared in that thread, the first version of CesiumJS Sandcastle Copilot is now available in Sandcastle:

Sandcastle | CesiumJS

What is Sandcastle Copilot?

Sandcastle Copilot is an AI-assisted chat panel built directly into Sandcastle. It is designed to help developers move from an idea to working CesiumJS code faster, while keeping the normal Sandcastle workflow intact.

With Sandcastle Copilot, you can:

• Ask questions about CesiumJS and the active Sandcastle
• Request scene changes using natural language
• Generate or edit JavaScript, HTML, and CSS
• Review proposed code changes as diffs before applying them
• Use console and runtime context to help diagnose errors

The goal is to reduce friction for people who are learning CesiumJS, including non-technical users and developers alike, while also speeding up prototyping for experienced users exploring new scene ideas, APIs, or datasets.

Bring Your Own Key

The initial release uses a bring-your-own-key model. Before starting a chat, you connect Sandcastle Copilot to an LLM provider you already use.

This keeps the first version lightweight and gives developers control over the model, API key, and account used for their conversations.

We’d Love Your Feedback

This is an initial release, and your feedback will help shape where it goes next.

A few areas where your input would be especially helpful:

1. Your experience
   Have you tried Sandcastle Copilot yet? What did you ask it to build, explain, or debug?

2. Sandcastle context
   Did Copilot understand the active Sandcastle and generate suggestions that were relevant to the code you were working with?

3. Code review workflow
   Were the generated diffs easy to understand and review before applying?

4. Debugging
   If you used Copilot with console errors or runtime issues, did it help you identify the problem?

5. Missing capabilities
   What CesiumJS workflows should Sandcastle Copilot support next? For example:

   • Working with Cesium ion assets
   • Styling 3D Tiles
   • Managing camera views
   • Generating flight paths
   • Explaining unfamiliar CesiumJS APIs
   • Something else?

6. Concerns
   What technical challenges, confusing behavior, or pitfalls should we be careful to avoid as this evolves?

Continuing the Conversation

This launch builds on the earlier feedback discussion here:

FEEDBACK REQUESTED: Native AI Copilot for Sandcastle

Hello Cesium Community, The purpose of this post is to open a technical discussion regarding the next evolution for Sandcastle: integrating a native, agentic AI Copilot. As AI-assisted development tools continue to evolve, we’re curious about your experiences using them with CesiumJS and Sandcastle. What has worked well? What challenges have you encountered? The Vision: An Integrated AI Agent We’re exploring whether a native AI agent integrated directly into Sandcastle could enhance the devel…

If you contributed there, thank you. That input helped clarify what would be most useful in an AI-assisted Sandcastle workflow.

Whether you are excited, skeptical, or just curious, we would love for you to try the first version and share what you find.

Try it here:

Sandcastle | CesiumJS

Looking forward to the discussion!