The Eclipse Theia Community Release 2025-05

We are delighted to announce the tenth Eclipse Theia community release, “2025-05,” incorporating the latest advances from Theia releases 1.59, 1.60, and 1.61.

Special Note for Adopters: This community release includes the migration from PhosphorJS to Lumino as the underlying widget framework, introduced in Theia 1.60. While this change is largely internal and most adopters should not need to adjust their code, we recommend carefully testing UI elements related to the workbench for possible regressions. If you have implemented customizations that directly depend on PhosphorJS internals, these will need to be updated to work with Lumino. Please review the detailed migration information in the 1.60 release notes and report any issues.

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Community releases are provided quarterly and serve as stable anchors for downstream adopters. Each combines features, fixes, and hardening from three monthly releases. Learn more about the advantages of the community release, or visit Theia’s releases page.

Let’s explore key highlights from this tenth Theia community release!

Highlights of the Theia 2025-05 Community Release

This community release ships cumulative improvements from releases 1.59, 1.60 and 1.61, in total 247 improvements. For a comprehensive list of changes, please see the individual announcements. Here are some top highlights:

Theia AI & Chat: Smarter Agents, Task Contexts, and Better Usability

Theia AI continues to power next-gen developer experiences, and this cycle brings key improvements:

• Task Contexts & Persistent AI Memory: Theia AI 1.61 introduces task contexts—a novel mechanism for persisting all relevant context around a development task. They enable modular, multi-stage AI workflows. (Details)
• Chat Suggestions & Editable Prompts: Interactive suggestions guide users through common workflows or next steps. Chat requests are now editable, supporting easy iteration and branching in AI conversations. (Details)
• Follow-up and agent pinning: Smarter agent workflows via agent pinning and follow-up suggestions improve efficiency and workflow guidance. (Details)
• Project Info Prompt Fragments: Project-wide conventions can now be described in dedicated files, ensuring AI agents such as Theia Coder align with best practices. (Learn more)
• Token Usage Reporting: Track and manage AI token consumption across providers right from the IDE! (Details)
• Customizable Welcome Messages, Improved Naming: The chat view sports personalized welcome screens and auto-generated session naming for better organization. (Details)

Theia Coder & AI-Powered Coding

Theia Coder, the open and transparent AI coding agent (an open-source alternative to tools such as Cursor or Github Copilot) for Theia, was significantly enhanced:

• Seamless Context, Changeset & Diagnostic Integration: Specify context easily, streamline code reviews, and auto-detect/fix issues using diagnostics—all from the AI chat. (Details)
• Workspace Search and Task Tools: Agents can now search across the workspace and launch build/test tasks autonomously. (Details)
• SCANOSS Integration: Automatically scan generated code for license compliance. (Details)

Advanced LLM & Provider Support: Google AI, Thinking Mode & More

• Google AI / Gemini Provider: Native support for Google AI and Gemini model families. (Details)
• Claude’s Thinking Mode: Enable deep, reflective reasoning in complex tasks by setting a custom parameter in chat sessions. (Details)
• LLM Compatibility: Improved compatibility with various LLM of supported providers (Anthropic, Azure, Hugging Face, OpenAI, Google, Ollama, DeepSeek, and more). (Why Theia supports any LLM)

Workflow Improvements: Prompt Fragments, Workspace & Project Customization

• Prompt Fragments: Create reusable prompt templates for repetitive coding or review tasks—now referenceable in chat and agent prompt editors. (Details)
• Workspace-specific Custom Agents: Define custom agents and prompts per workspace, enabling domain or project-specific AI workflows. (Details)
• Improved Dev Container Support: Easily set Dev Container environment variables on project startup. (Details)

UI, Extensibility, and Stability Enhancements

• Migration to Lumino: The underlying widget system migrated to Lumino for better stability and long-term maintainability. (Details)
• Extension Disabling UI: Quickly disable plugins and built-in VS Code extensions from the UI. (Details)
• New Yeoman Tree Widget Example: Quickly scaffold and explore custom Theia widgets in your app. (Details)

For a comprehensive breakdown, please read the in-depth release news:

• Eclipse Theia 1.59 announcement
• Eclipse Theia 1.60 announcement
• Eclipse Theia 1.61 announcement

Build or Extend Your Own IDE or Tool with Eclipse Theia

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 and IDEs, for Tools or extensions based on VS Coder as well as for web-based tools in general. We also provide a new Eclipse Theia online training that you can take anytime for a running start with Theia extension development. If you want to extend Theia with features or bug fixes, EclipseSource provides sponsored development for Theia, too. Finally, for cloud deployments we offer consulting and support for web-based tools.

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