Eclipse Theia 1.58 Release: News and Noteworthy

We are happy to announce the Eclipse Theia 1.58 release! The release contains in total 95 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 IDEs with ease. For more details about Eclipse Theia, please refer to this article and visit the Theia website.

The Theia 1.58 release is the first release candidate for the next community release 2024-02. So if you plan to adopt the next community release, please verify the 1.58 release and report important issues for your use case!

Please note that with the Theia 1.58 release, Theia has switched from using Yarn to NPM. We are not aware of any consequences for downstream adopters (yet), you can use the build tool you have used before and do not have to switch. If you discover any issues, please provide feedback.

The Theia project also releases a product, the Theia IDE. The Eclipse Theia IDE is a modern, AI-powered, and open IDE for cloud and desktop environments, aimed at end users. The Theia IDE is based on the Theia platform and also includes AI powered assistants. 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 1.58.

Eclipse Theia 1.58: Selected features and improvements

In the following, we will highlight some selected improvements in the new release. As usual, we cannot mention all 95 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 Coder (preview): AI-Powered Code Assistance in the Theia IDE

With Theia 1.58, we are excited to introduce Theia Coder, an AI-powered coding agent designed to assist developers with structured code modifications directly within the Theia IDE. Theia Coder can browse the workspace, retrieve relevant context, and propose code changes that users can review and apply seamlessly. This new agent is currently available as a preview version, and we encourage users to test it and provide feedback.

To get started, simply reference @Coder in the Theia AI chat and describe your programming task in natural language. Theia Coder currently supports two prompt variants:

• Default: Replaces full files when proposing changes, ensuring high accuracy but potentially slower responses.

• coder-search-replace: Also uses a search-and-replace approach for faster modifications. This is the recommended option, but users can switch back to the default if needed. You can configure this in the AI Configuration view under Coder → Prompt Templates.

To see Theia Coder in action, check out this video demonstration showcasing a full workflow example.

Demonstration of Theia Coder (preview): The AI-Powered Code Assistant in the Theia IDE

For more details on how to use Theia Coder, including specifying context, reviewing changes, and optimizing AI-driven development, refer to the full documentation. Theia Coder is built on Theia AI, a flexible framework for AI-powered tools and IDEs, allowing easy customization and extension. Try it out today, provide feedback and contribute your ideas and refinements!

Introducing ChangeSets in Theia AI

Theia 1.58 introduces ChangeSets in Theia AI, a powerful new feature that allows AI agents—such as the Theia Coder agent—to propose changes that users can review, refine, and apply seamlessly.

With ChangeSets, AI-generated changes are no longer applied directly but instead presented for review in a dedicated UI within the AI chat (see the video in the previous section). Users can inspect proposed edits, approve or decline them, and even make refinements before committing changes. In Theia IDE, ChangeSets are particularly useful for file-based modifications, allowing users to work more efficiently with AI-powered code assistance.

Changesets in Theia AI allow proposing changes that users can review, refine, and apply seamlessly.

However, ChangeSets are not limited to code edits—they provide a flexible framework for tool builders. Adopters can extend ChangeSets to support a variety of domain-specific modifications, such as changes to databases, structured models, or other application-specific data. By implementing custom ChangeSet elements, tool builders can leverage the existing review and approval workflow while tailoring the system to their needs.

For more details on how to integrate and customize ChangeSets, refer to the full documentation.

Enhanced AI-powered Code Completion

In Theia 1.58, we’ve introduced several enhancements to the AI code completion agent to improve your development experience:

• New Keybinding for Manual Trigger: The keybinding to manually trigger code completion suggestions has been updated to Ctrl+Alt+Space (PR #14669). Please note that automatic inline suggestions are currently disabled by default; you can enable them in the settings to receive continuous suggestions.

• Performance Improvements: We’ve significantly improved the performance of the auto-completion feature, ensuring faster and more efficient suggestions during your coding sessions (PR #14769).

• Filtered Backticks in Suggestions: The code completion agent can now filter out surrounding backticks from completion suggestions, which are sometimes added by certain language models (PR #14777). This results in cleaner and more accurate code insertions.

• Alternative Prompt Template: We’ve added an alternative prompt template for code completion (PR #14777). You can select it in the ‘AI Configuration’ view under ‘Code Completion’ > ‘Prompt Templates’. We plan to make this the default in upcoming releases, so we encourage you to test it and provide feedback.

Also browse our documentation for the AI code completion in the Theia IDE.

Autostart for MCP servers

Theia 1.58 adds a new setting for configured MCP servers to be automatically started on tool start. See also the MCP Documentation for Theia AI.

MCP is an open standard that enables secure, two-way connections between external systems and AI-powered tools, facilitating seamless integration with various services.

Learn more about MCP:

👉 Theia AI and the Theia IDE support the Model Context Protocol

Please note that in browser deployments, MCP servers are scoped per connection. This means that if you manually start an MCP server, you need to start it once per browser tab to ensure functionality across multiple tabs. Autostart will of course work for any new tab you open.

Support OpenAI API on Azure

In Theia 1.58, we’ve expanded our AI integration capabilities by adding support for Azure OpenAI. This enhancement allows users to seamlessly connect Theia’s AI features with OpenAI models hosted on Microsoft’s Azure platform. Azure has some specifics compared to the official OpenAI platform, such as the use of developer messages, which are now supported in Theia AI. Supporting Azure OpenAI is particularly valuable for internal deployments, where organizations need to keep AI processing within their infrastructure, as well as for tool builders who want full control over the LLM used in their custom AI-powered tools and IDEs based on Theia AI.

See the documentation on custom OpenAI endpoints for more information.

Theia AI: Support for tool functions for Anthropic and Ollama

Theia AI 1.58 introduces tool function support for both Anthropic and Ollama language models, as detailed in PR #14623 and PR #14758. This enhancement enables seamless integration of external tools and APIs, allowing AI agents within Theia to perform complex tasks such as code execution, web searches, and data manipulation. The inclusion of tool functions is crucial for implementing agentic workflows and developing intelligent agents like Theia Coder, which rely on dynamic interactions with various tools to automate and streamline development processes. Moreover, this development aligns with Theia’s support for the Model Context Protocol (MCP), an open standard that facilitates secure, two-way connections between external systems and AI-powered tools.

Support dragging files in browser

Theia 1.58 enhances the user experience for browser-based applications by introducing support for dragging and dropping files directly from your operating system’s file explorer into Theia’s main area (see screenshot below). This feature allows users to seamlessly open local files within Theia by reading their contents upon drop, eliminating the need for manual uploads or navigation. This improvement streamlines workflows and brings the browser experience closer to that of desktop applications.

Update monaco-editor to 1.96.3

In Theia 1.58, we’ve upgraded the integrated Monaco editor to version 1.93.3, bringing lots  of enhancements and new features. This improvement streamlines code exploration and editing within Theia. For a comprehensive overview of the updates included in this upgrade, please refer to the following Visual Studio Code release notes:

1.84, 1.85, 1.86, 1.87, 1.88, 1.91, 1.92, 1.93, 1.94, 1.95, 1.96

As an example, the minimap now supports section headers, allowing for easy navigation through large files. By adding section headers as comments, these will be highlighted and clickable in the minimap, facilitating quick access to different code sections (see screenshot below)

Theia switches from yarn to npm

In Theia 1.58, we’ve transitioned our build process from Yarn to npm. This change aims to streamline our development workflow and align with industry standards. We are not aware of any consequences for downstream adopters; you can continue using your preferred build tool without the need to switch. If you encounter any issues related to this transition, please provide feedback so we can address them promptly.

All these features and improvements (in total 95) were the result of two weeks 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!