Show HN: OculOS – Any desktop app as a JSON API via OS accessibility tree | Hacker News Reader

Show HN: OculOS – Any desktop app as a JSON API via OS accessibility tree

github.com

18 pointsstif13379 comments

Single Rust binary (~3 MB) that reads the OS accessibility tree and gives every UI element a REST endpoint. Click buttons, type text, toggle checkboxes — all via JSON. Works as an MCP server too, so Claude/Cursor/Windsurf can control any desktop app out of the box.

Windows + Linux + macOS. MIT licensed.

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Update: Since the initial post, I've shipped several features based on feedback:

- Screenshot capture: GET /windows/{pid}/screenshot → returns PNG

- Batch operations: POST /interact/batch → multiple actions per request

- Wait/poll: GET /windows/{pid}/wait?q=Submit&timeout=5000

- Python & TypeScript SDKs (local install, PyPI/npm coming soon)

- OpenAPI spec, Dockerfile, 7 example scripts

- Demo GIF in README showing Calculator automation via Claude Code

Thanks for the feedback everyone!

I wonder whether this requires particular GUI toolkits to be used, such as WFC. In any GUI there are enough "bad boy" toolkits which just "draw lines" and thus are not accessible at all.

No toolkit dependency, OculOS reads the OS-level accessibility tree, which is toolkit-agnostic:

- Windows: UI Automation (works with Win32, WPF, WinForms, Qt, Electron) - Linux: AT-SPI2 (GTK, Qt, Electron) - macOS: AXUIElement (Cocoa, Qt, Electron)

The coverage varies by toolkit. Win32/WPF/GTK expose rich trees. Electron apps expose key elements but the tree is shallower. Custom-drawn UIs (games, OpenGL) have minimal or no accessibility tree. That's the main limitation.

Cool idea! Does this work with electron apps? I tried automating some apps and the problem was that a lot of stuff was never reachable, only via screenshot + click

Yes, electron apps expose a reasonable accessibility tree through Chromium's UIA/AT-SPI bridge. We've tested with Spotify (Electron/CEF), VS Code, Slack, and Chrome itself.

The tree is shallower than native Win32/WPF apps, but key interactive elements (buttons, inputs, lists) are usually exposed. You can check what's available with:

  curl "localhost:7878/windows/{pid}/find?interactive=true"

Maybe I need to familiarize myself with MCP, but wouldn't this make way more sense as a simple CLI tool instead of an HTTP service with a REST API?

It actually supports both you can use it as a plain REST API (no MCP needed) with any HTTP client:

  curl localhost:7878/windows
  curl -X POST localhost:7878/interact/{id}/click

MCP mode is an optional layer for AI agents (Claude, Cursor, etc.) that already speak MCP. The REST API works standalone for scripts, testing, CI/CD — no AI required.

Good idea, I'm looking forward to seeing it grow - especially the Python and TypeScript bindings.

Thanks! Python and TypeScript SDKs are high on the roadmap.

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