Eclipse Theia 1.55 Release: News and Noteworthy

We are happy to announce the Eclipse Theia 1.54 release! The release contains 82 merged pull requests. In this article, we will highlight some selected improvements and provide an overview of the latest news around Theia.

For those new to Eclipse Theia, it is the next-generation platform for building IDEs and tools for the web or desktop, based on modern state-of-the-art web technologies. With Theia AI, part of the Theia platform, you can also build AI-powered tools and IDE with ease. For more details, please refer to this article and visit the Theia website.

We are happy to announce that registrations are now OPEN for the 2024 TheiaCon! TheiaCon is an annual virtual conference focused around the Eclipse Theia ecosystem. It brings together a diverse group of Theia developers, adopters, and other contributors. The program will feature a mix of full-length talks, expert panel discussions and short lightning talks featuring project contributor insights, adopter stories, and work being done in the broader ecosystem. TheiaCon is a virtual event on November 13th and 14th 2024. So, get registered now!

The Theia 1.55 release is the first release candidate for the next community release 2024-11. So if you plan to adopt the next community release, please verify the 1.55 release and report important issues for your use case!

The Theia project also releases a product, the Theia IDE. The Eclipse Theia IDE is a modern and open IDE for cloud and desktop aimed at end users. The Theia IDE is based on the Theia platform. For more details, see the Theia IDE website.\

Remember that the Theia IDE left its beta phase and is now generally available (already with release 1.51). Also, see the press release, the blog post and the section below about this.

If you are looking for a simple way to check out the new release, please download and install the Theia IDE, which is based on Theia 1.55.

Eclipse Theia 1.55: Selected features and improvements

In the following, we will highlight some selected improvements in the new release. As usual, we cannot mention all 82 improvements, however we will focus on the most notable changes as well as changes visible to end users. The corresponding pull requests are linked under the respective heading when applicable.

Theia IDE available on Snap

The Theia IDE is now available on Snap, offering users a simplified installation process across various Linux distributions. By providing the Theia IDE as a Snap package, users benefit from automatic updates and increased security through Snap’s containerized packaging system. The installation is straightforward, enabling users to install and run Theia with minimal setup, regardless of their specific Linux environment. You can access the Theia Snap package here.

Theia AI: Support for custom agents

Theia 1.55 introduces custom chat agents, a feature enabling users to define personalized, automated workflows directly within the Theia IDE. These agents integrate seamlessly into the Theia workbench, allowing developers to perform complex, repeatable tasks—such as code obfuscation, security scanning, and test generation. With easy setup in the AI Configuration View, users can configure agents through a simple YAML file, choosing specific prompts, data access and even the preferred language model.

As any agent, custom agents can have access to project files and context, which unlocks powerful capabilities for tailored automation. For instance, users can create agents that review code quality, scan for security vulnerabilities, or generate domain-specific documentation in real time, leveraging the agent’s workspace access. The screenshot below demonstrates adding a simple custom Python agent.

This feature is built on Theia AI, a flexible framework for developing AI-powered solutions within Theia. For more details on custom agents and advanced configurations, please refer to our dedicated blog post.

Support for Llama-File as an LLM Provider

Theia 1.55, powered by Theia AI, now integrates support for LlamaFile, enabling developers to run local AI models seamlessly within their environment. This support is available out of the box directly in the Theia IDE, allowing users to configure and manage LlamaFile models with minimal setup. By adding simple settings—such as model name, URI, and port—users can quickly start and stop their models through dedicated commands in Theia.

This integration reflects Theia AI’s commitment to providing secure, flexible AI solutions that operate locally. With LlamaFile support, developers gain control over their data and AI resources without relying on cloud-based models, enhancing privacy, cost efficiency, and offline functionality.

Preference to exclude files from AI code completion

The Theia IDE 1.55 introduces a new preference to exclude files by extension from code completion suggestions. By specifying extensions in the settings (e.g., .md), users can disable code completion for particular file types, which is especially useful for files where suggestions are not needed.

Improve widget specific status bar handling

Theia 1.55 improves the handling of status bar items by introducing a WidgetStatusBarService, which adjusts displayed items based on the active widget. When specific widgets like the Monaco Code editor or custom editors are selected, only their relevant status items are shown, and unrelated items are hidden (see screenshot below). This ensures a cleaner, context-appropriate status bar view, improving focus and usability across different editor types.

Support for O1-Preview in the Theia IDE

Theia 1.55 adds support for OpenAI’s O1-Preview model, tailored for reasoning-intensive tasks like complex coding and algorithmic challenges. Thanks to its advanced chain-of-thought reasoning, O1 can break down and solve multi-step coding problems with high accuracy, making it valuable for developers tackling complex tasks in IDEs (see Geeky Gadgets, Louis Bouchard AI).

While Theia allows flexibility to integrate various LLMs with any agent, O1-Preview is wrapped in a dedicated agent due to its slower response times. Without streaming support, O1 can take considerably longer to generate responses, so this dedicated setup enables developers to choose explicitly when they wish to engage O1, avoiding interruptions to regular workflows. This approach provides Theia users with control over when to leverage O1’s robust problem-solving capabilities, especially suited for intricate coding tasks where accuracy is paramount.

API Key support for custom LLMs

Theia 1.55 enhances its flexibility in terms of connecting to arbitrary LLMs by enabling API key passthrough for custom OpenAI-compatible models, allowing developers to configure secure access to various LLMs, including self-hosted and third-party models. This capability supports a wide range of AI setups within Theia, giving users the freedom to connect to both proprietary and locally hosted models according to their project needs. With this update, Theia reinforces its role as a versatile framework for building AI-powered tools that integrates seamlessly with diverse AI resources, ensuring secure and adaptable AI support.

Various Platform Improvements

Theia 1.55 introduces a set of platform enhancements that increase flexibility, customization, and ease of testing across the IDE:

• Extensible AI Response Parsing (#14196): The AI response parsing within Theia is now fully extensible, allowing developers to customize how responses from different AI models are interpreted and displayed. This means users can define specific parsing rules or add new matchers for tailored processing, which is particularly useful when working with multiple LLMs that may output data in different formats.

• Customizable LLM Request Settings (#14284): Theia now enables users to adjust request settings for different large language models (LLMs), providing greater control over parameters like temperature and max tokens on a per-model basis. This customization allows developers to fine-tune the behavior of individual models, optimizing them for specific coding or analytical tasks. It also supports experimentation with model settings directly within the IDE, making it easier to achieve the desired AI performance for each project.

• Configurable Configuration Area for Custom Applications (#14319): This update introduces support for defining a custom configuration directory path for Theia-based applications. For organizations creating bespoke Theia setups, this feature allows the IDE to store configurations in a specified location, which helps with application packaging and deployment. It streamlines workflows for teams that need custom application environments while retaining Theia’s flexibility as a framework.

• Playwright API for Notebooks (#14098): Theia’s notebook functionality now integrates with Playwright, enabling comprehensive end-to-end testing for notebooks directly within the IDE. This Playwright API support allows developers to automate testing for complex notebook workflows, ensuring consistent behavior and reliability across different scenarios. With this capability, Theia better supports data science and documentation workflows, where testing interactive notebook components is critical.

As always, the 1.55 release contains much more than described in this article, e.g. the support for the VS Code extension API has been upgraded to support 1.94.1. All these features and improvements (in total 82) were the result of one month of intensive development. Eclipse Theia follows a monthly release schedule. We are looking forward to the next release due next month, stay tuned! To be notified about future releases, follow Theia on Twitter and subscribe to our mailing list.

If you are interested in building custom tools or IDEs based on Eclipse Theia, EclipseSource provides consulting and implementation services for Eclipse Theia, for AI-powered tools, as well as for web-based tools in general. We are happy to announce that we provide a new Eclipse Theia online training that you can conduct anytime, anywhere. It provides you and your team with a jump start for the development of your own custom solutions based on Eclipse Theia extensions.

Furthermore, if you want to extend Theia with features such as the toolbar or the test framework, EclipseSource provides sponsored development for Theia, too. Finally, we provide consulting and support for hosting web-based tools in the cloud. Get in contact with us, to discuss your use case!