Features: what UltraNOS does in the browser

Last updated: October 23, 2026

UltraNOS is a workspace, not a chat window with code blocks. Everything below runs in the browser against a workspace on the server: no installer, no local setup, the same session on every device. This page lists what is actually built, not what is planned.

Agents

• Multi-agent chat with streaming, sessions and tool calls. Several agents work at the same time, visible in a fleet view with live output, tool badges and a stop button.
• Agentic loop: autonomous think→act→check cycles in the background, with caps on rounds and errors.
• Sub-agents via spawn_agent from the chat, with a depth limit and a cap on concurrent jobs, so an agent cannot quietly start a swarm.
• Cross-chat: one session asks another and waits for its answer. Specialist knowledge stays where it was collected.
• Pipeline: plan → code → test → review → security → verify, with a judge model and a jump back on failure.
• Loop guard and time budget: if an agent repeats the same tool call with the same result, it gets a warning first and is then stopped. Every turn also runs against a clock. Both exist because agents otherwise circle quietly and burn money.
• Tool approvals and guards: unsafe calls ask first, rules such as no-rm-rf or no-force-push block dangerous commands, and you can add your own patterns.

Development environment

• Monaco editor with tabs, change markers, Cmd+S, jump to line and inline suggestions as ghost text.
• File tree with a context menu, git status colors and drag and drop across the whole surface; files and folders can be downloaded as ZIP.
• Real terminal: a PTY shell over WebSocket, no SSH keys needed, with a special-keys bar on the phone.
• Git: status, stage, commit, push, branches, stash, blame, AI commit messages, and cloning with partial clone as the default for large repositories.
• UltraForge: a built-in git server with repos, issues, pull requests and merge, in case you do not want your code stored elsewhere.
• Search: file name (Cmd+P), content (Cmd+Shift+F) and one search across code, chat history, memory and files at once.
• Code map and nerve map: symbol graph, function-level call graph and a blast radius that shows what a change touches.
• Lint and build: ruff and JS checks as diagnostics in the editor, build detection with a live log, artifacts to download.

Run and publish

• Run with reverse proxy: start a dev server and reach it at a stable address without opening a port.
• Deployments: static sites and running services, with HTML rewriting and WebSocket passthrough.
• Play rooms: one screen, many phones — a room code and a QR code instead of port forwarding.

Memory and knowledge

• Persistent memory across all sessions (Centre AI), with matching excerpts fed into every chat.
• Codebase intelligence: a file watcher keeps the index current, and search uses TF-IDF instead of third-party embedding services.
• Skills: 60 bundled templates in nine categories, plus Fabric patterns.

Models and integration

• Free choice of model: Claude (API or CLI), OpenAI-compatible endpoints, Ollama or your own endpoint. Bring your own key; no lock-in to one provider.
• Model routing: a separate model per job — chat, tasks, subtasks, commit message, plan, review, summary.
• Remote API and MCP server: other programs can drive UltraNOS remotely; in return you can plug in third-party MCP servers.
• Browser and desktop tools: a Playwright session with a live image, plus keyboard and mouse actions on the server desktop.
• On the go: a Telegram bot, an installable PWA and an Android app.

Protection and operations

• cloak: API keys, credentials and email addresses are replaced with placeholders before a request reaches the model provider. Detection, limits and how to verify it are written out in the post on cloak.
• Load limits on every process that is started (compute time, file size, process count, memory via cgroups) and a sandbox for the terminal and builds.
• Multi-tenant: separate workspaces, storage quotas per plan, data export under Art. 15 and 20 GDPR.
• Server location Nuremberg (Hetzner), data processing agreement available.

What UltraNOS is not

Not a VS Code fork and not a desktop application — apart from the Android app, everything runs in the browser. The repository is not public; self-hosting is possible, but on request. And the language models come from the provider you choose: UltraNOS builds the workspace around them, not the model.

Prices are on the pricing page; getting started takes as long as signing up.