theia-code-os

The @theia/ai-core extension serves as the basis of all AI integration in Theia. It manages the integration of language models and provides core concepts like agents, prompts, AI variables, and skills.

Skills

Skills provide reusable instructions and domain knowledge for AI agents. A skill is a directory containing a SKILL.md file with YAML frontmatter (name, description) and markdown content.

Skill Directories

Skills are discovered from multiple locations, processed in priority order (first wins on duplicates):

Workspace: .prompts/skills/ in the workspace root (project-specific skills)
User-configured: Directories listed in ai-features.skills.skillDirectories preference
Global: ~/.theia/skills/ (user defaults)

Skill Structure

Each skill must be in its own directory with the directory name matching the skill name:

skills/
├── my-skill/
│   └── SKILL.md
└── another-skill/
    └── SKILL.md

Usage

Add {{skills}} to an agent's prompt to inject available skills as XML (name and description)
Agents can read full skill content using the getSkillFileContent tool with the skill name

Enablement of the Theia AI feature is managed via the AI preferences, contributed by @theia/ai-core-ui. Either include @theia/ai-core-ui or bind the included preferences schemas in your Theia based application.

Additional Information

License

Trademark

"Theia" is a trademark of the Eclipse Foundation https://www.eclipse.org/theia