Theia Documentation – Build Custom IDEs and Tools

In this section, we provide a high level overview on how to get started with Eclipse Theia and link to respective sections to read. Eclipse Theia is a platform for building custom Cloud & Desktop IDEs and tools with modern web technologies. The Eclipse Theia Platform is not a tool itself, but there are many tools which are built upon Theia. The Theia project provides a tool called Eclipse Theia IDE that can be directly used. The Theia IDE can also be used as a template to get started with building your own tool. Please have a look at the project goals for more details!
You cannot directly launch/use Theia as it is a platform. The project provides one tool called Theia IDE that you can directly download and use. Further, it is very easy to create your own product based on Theia. Please also refer to this article highlighting the various options available to launch/try Eclipse Theia and Theia-based products.
The first step is to define a custom product based on Theia. Please check out the guide on how to build your own IDE or tool based on Theia. Subsequently, you might want to extend this product with your own feature for which you can use the available extension mechanisms of Theia.
Theia provides comprehensive, native support for AI across two key dimensions:
Theia AI is an open-source, vendor-neutral AI harness platform integrated into the Theia Platform that enables you to build custom, AI-native tools and IDEs with complete control over the user experience, AI agents, language models, and data integrations. It provides a ready-to-use default harness as well as support for MCP, Agent Skills, Plugins and other emerging agent standards. Whether you need domain-specific AI agents, custom chat interfaces, or seamless integration with your existing tool ecosystem, Theia AI provides the flexibility to create tailored AI solutions that fit your exact requirements.
The Theia IDE comes with extensive AI coding support built on Theia AI, offering a transparent and open alternative to proprietary AI development tools. With the AI-native Theia IDE, you get powerful AI coding assistance while maintaining full control over your development workflow and data.
If you are unsure what Theia is, how it compares to other technologies or how to migrate Eclipse-based tools to it, please have a look at Theia FAQ.
Theia is an open community, and we are glad to help you. You can ask questions using our public community forum, you can report bugs and feature requests, and you can get professional support, consulting and implementation services for building products based on Theia.
Also follow Theia on X to stay up-to-date!
Read below to learn how to take part in improving Theia:
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