# Theo · Studio (E.V.I. Canvas)

> The visual build surface for AI Workers. Drag-drop nodes for persona, skill, knowledge, tool, conditional, and vision. Wire them with workflows and hooks. Compile, test, version, publish.

Source of truth: https://hitheo.ai/studio. Last updated: 2026-05-24.

## At a glance
- Six subsystems: Canvas, Skills, Knowledge Node, Workflows, Hooks, Tool Registry.
- Three publish modes: private, organization-only, public marketplace.
- Versioned drafts. Every save is reversible.
- Live compile + test against sample prompts.

## The six subsystems
1. E.V.I. Canvas. The workshop. An infinite grid where nodes are dragged on, wired, compiled, and published.
2. Skills. The unit of reusable intelligence. A skill bundles a prompt, the right tools, the right knowledge, and an optional workflow. See https://hitheo.ai/llms/skills.txt.
3. Knowledge Node. Drop PDFs, DOCX, XLSX, CSV, JSON, and Markdown directly onto a skill. Limits: 10MB per file, 100 files per skill, 50K-token runtime budget per request. Priority weighting 1 to 5 (P1 gets 3× the budget share). Stored in org-scoped object storage.
4. Workflows. Step-based execution engine. Six step types: tool_call, ai_transform, condition, delay, notification, webhook. N-ary branching. 10-step cap. 30-min runtime cap. Credit checkpoint before every step. See https://hitheo.ai/llms/workers.txt.
5. Hooks. Autonomous triggers on domain events. Five preset event patterns (share.accepted.welcome, task.overdue.summary, project.created.suggestions, team.member_joined.onboarding, document.analyzed.followup) plus custom patterns.
6. Tool Registry. Built-in tools (memory, code, research, browser, documents) + skill tools + connector tools. Four permission tiers: user, org_member, org_admin, system. Every call audited.

## Authoring loop
1. Open the canvas at /dashboard/skills/canvas.
2. Drop nodes onto the grid. Wire them with conditionals and tool calls.
3. Compile. The canvas compiler walks the graph and produces a SkillManifest + WorkflowSteps[].
4. Test. Run sample prompts through the compiled skill inside the canvas.
5. Version. Every save is reversible.
6. Publish. Private (you only) → organization (your team) → public (marketplace).

## Related machine-readable files
- https://hitheo.ai/llms.txt — full index of every Theo machine-readable file.
- https://hitheo.ai/llms-full.txt — long-form knowledge bundle (single fetch).
- https://hitheo.ai/humans.txt — team and open-source credits.
- https://hitheo.ai/lawyers.txt — trademark notice and legal contact.
- https://hitheo.ai/.well-known/security.txt — security disclosure contact.