Eclipse Theia 1.67 Release: News and Noteworthy

We are happy to announce the Eclipse Theia 1.67 release! The release contains in total 92 merged pull requests. In this article, we will highlight some selected improvements and provide an overview of the latest news around Theia.

Before diving into the release details, we want to highlight our recently published article on Investing in Eclipse Theia. If you or your organization rely on Theia as a strategic platform, the article outlines two complementary paths to support the project: collective sponsoring via Open Collective and sponsored development through strategic contributors. Both options help ensure the platform remains robust, well-maintained, and evolving to meet modern development needs.

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 project also releases a product, the Theia IDE. The Eclipse Theia IDE is a modern, AI-native, and open IDE for cloud and desktop environments, aimed at end users. The Theia IDE is based on the Theia platform and also includes advanced AI powered features. For more details, see the Theia IDE website.

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 1.67.

Eclipse Theia 1.67: Selected features and improvements

In the following, we will highlight some selected improvements in the new release. As usual, we cannot mention all 92 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.

Terminal Manager for Multiple Terminals

Theia 1.67 introduces a new terminal-manager extension that enables managing multiple terminals within a single view. This long-requested feature allows users to organize their terminal sessions more efficiently by splitting them vertically or horizontally and grouping them into pages.

The new Terminal Manager provides a tree-based navigation panel on the left side, making it easy to switch between terminals, rename them, and organize them into logical groups. Users can create new terminal groups, split existing terminals, and drag terminals between groups—all within a unified interface that reduces the clutter of having many separate terminal tabs.

The behavior is controlled via the terminal.grouping.mode preference. Setting it to tree enables the new Terminal Manager experience, while the default separate mode preserves the traditional behavior where each terminal opens as an independent view. This allows users and adopters to choose the workflow that best suits their needs.

Improved Theia AI Onboarding Experience

First-time users of Theia AI now benefit from a significantly improved onboarding experience. When the AI chat is opened without proper configuration, users are greeted with helpful welcome screens that guide them through the setup process.

The new welcome flow includes three distinct states: when AI features are disabled, when language models aren’t configured, and when a default agent hasn’t been selected. Each state provides clear guidance on how to proceed. For example, if no API keys are configured, the welcome page displays which models are missing configuration and provides direct links to the relevant settings.

Once at least one language model is properly configured, users are prompted to select a default agent. The interface offers quick recommendations for popular agents like Theia Coder, making it easy to get started with just a single click.

Importantly, when no default agent is configured, the chat no longer automatically delegates requests to the Orchestrator agent. In previous versions, this fallback behavior often confused new users who didn’t understand why the AI responded in a particular way or what the Orchestrator’s role was. Now, the system explicitly asks users to configure a default agent first, providing a much clearer starting point for working with Theia AI.

Claude Code Session Forking

The Claude Code integration in Theia AI now supports automatic session forking when users edit previous requests in a conversation. This feature enables exploring alternative conversation paths while preserving the original thread—a capability that proves invaluable when iterating on AI-assisted coding tasks.

When you edit a request that was already part of an existing Claude Code session, Theia automatically creates a fork of the session rather than continuing in the same context. This means your original conversation remains intact while you explore a different approach. The feature leverages Theia’s existing chat hierarchy infrastructure and works seamlessly with the chat persistence introduced in Theia 1.66.

Session forking is particularly useful when you want to try multiple approaches to a problem without losing the context of your initial attempt. For instance, if an AI suggestion didn’t quite match your expectations, you can edit your original request to refine it, and the system will branch off into a new session while keeping your first attempt accessible.

New Slash Commands

Theia 1.67 expands the slash command ecosystem with several powerful new commands that streamline common development workflows.

GitHub Integration Commands (PR #16704) build on the GitHub Agent introduced in Theia 1.66, providing convenient shortcuts for issue and pull request workflows. The /analyze-gh-ticket <ticket-number> command retrieves comprehensive GitHub issue details and creates a detailed implementation plan—or asks clarifying questions if requirements are unclear. For more direct action, /fix-gh-ticket <ticket-number> takes this a step further by actually implementing the solution when the ticket is deemed implementable. /address-gh-review <pr-number>, which retrieves all review comments from a pull request, categorizes them by type, and either implements the necessary changes or requests clarification on ambiguous feedback.

The Remember Command (PR #16639) addresses a common pain point in AI-assisted development: preserving important project context from conversations. By typing /remember, users can instruct the AI to analyze the current chat history and extract information that should be persisted—particularly focusing on corrections, clarifications, and project-specific details that were discussed. The command then delegates to the Project Info agent to update the project context file, ensuring that future AI interactions benefit from learned context. An optional topic hint can be provided to focus extraction on specific areas.

These commands demonstrate the power of Theia AI’s extensible slash command system, which allows complex multi-step workflows to be triggered with simple, memorable commands. The above mentioned commands are built in the Theia IDE, but users can also easily crete new slash commands on the fly to capture their custom worflows. (see the documentation for more details)

Debugging Improvements

Theia 1.67 delivers a comprehensive set of debugging enhancements.

Lazy Debug Variables (PR #16681) are now properly supported with dedicated UI. Debug adapters can return “lazy” variables, such as getters, that shouldn’t have their values retrieved until explicitly requested. Previously, Theia presented these as expandable placeholder nodes, which could make data structures difficult to understand. Now, lazy variables display a resolve button (eye icon) that users can click to fetch the actual value. If the result is a simple value, it replaces the placeholder inline; if it’s a structured value, the variable automatically expands to reveal its contents. This feature works consistently across the Variables view, Watch expressions, Debug Console, and Debug Hover. For automated workflows, the new debug.autoExpandLazyVariables preference can automatically resolve lazy variables without user interaction.

Debug Toolbar Keybindings (PR #16719) are now visible directly in the toolbar. The debug toolbar actions have been refactored to be command-based, meaning they now properly display their associated keyboard shortcuts in tooltips. This makes it easier for users to learn and remember debug shortcuts like Step Over (F10), Step Into (F11), and Continue (F5).

Breakpoint Management (PR #16700) has been enhanced with inline edit and remove actions in the Breakpoints view. Users can now quickly modify or delete breakpoints—including data breakpoints, function breakpoints, instruction breakpoints, and source breakpoints—directly from the breakpoint list without needing to navigate to the source code.

Variables View State Preservation (PR #16689) ensures that expanded variables remain expanded when stepping through code. Previously, the expansion state could be lost between debugger pauses, forcing users to repeatedly expand the same variables. The fix gives stable IDs to debug variables and scopes, and properly stores and restores the widget state for each stack frame—matching VS Code’s behavior.

Theia AI Improvements

Beyond the headline features, Theia 1.67 includes numerous improvements to the AI infrastructure and default configurations.

Gemini Integration (PR #16664) has been updated with the latest @google/genai SDK (version 1.30.0), bringing proper support for Gemini’s thinking feature. The integration now correctly enables thinking mode via thinkingConfig.includeThoughts for streaming responses and properly preserves thought signatures when converting tool calls. Several fixes improve the handling of function responses and tool results to better comply with the Gemini API requirements.

Default Model Updates (PR #16636, PR #16656, PR #16734) refresh the out-of-the-box model configurations. For Anthropic, Claude Opus 4.5 has been added and is now the default in all model aliases. Google’s Gemini 3 joins the lineup alongside the existing Gemini 2.5 Pro and Flash models. OpenAI’s GPT 5.1 has been added while older models have been pruned to keep the list manageable. The model aliases have been updated accordingly to ensure users get the best available models by default. Please note that this is just about the pre-configured defaults, you can still use any LLM, including future ones with Theia AI, just by adding t to your configuration on the fly.

AI Configuration View (PR #16698) received a significant UI overhaul. The shared UI patterns across different configuration views have been extracted into reusable base components, improving consistency and maintainability. The views now handle different window sizes more gracefully and provide a more polished appearance across all AI configuration screens including Agents, Variables, MCP Servers, Token Usage, and Model Aliases.

Improved Code Editing Accuracy (PR #16597) comes from making the enhanced file replacer function—introduced experimentally in Theia 1.66—the new default. This more sophisticated content replacement strategy provides better accuracy when AI agents suggest code changes, reducing the likelihood of misapplied edits. The previous simpler implementation remains available but is now deprecated.

Additional Improvements

As always, the 1.67 release contains much more than described in this article. The compatibility with VS Code Extensions has been upgraded to API version 1.106.1, and the proposed Timeline API has been updated with improved tooltips and icon support (PR #16627).

The icon picker dialog for adding toolbar items has been improved with better filtering, fixed infinite scrolling, and updated codicons to version 0.0.42 (PR #16629). A critical fix addresses Electron startup crashes on pure Wayland environments like Ubuntu 25 (PR #16658). Terminal rendering has been enhanced with WebGL support, fixing cursor position issues when using Chinese input methods (PR #16605).

On the infrastructure side, the project has migrated to npm trusted publishing using OIDC authentication (PR #16630), improving security and streamlining the release process. Several localization improvements ensure user-facing text is properly internationalized, including enhanced ESLint checks for localization compliance (PR #16728).

For a complete overview of all changes in this release, please refer to the 1.67 milestone. All these features and improvements (in total 92) 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 us on LinkedIn or follow Theia on Twitter and subscribe to our mailing list.

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