UISandbox MCP server

Read from the package source without running it. The installed server may list more.

• export

  Export the current state: sheet-css (your values as CSS custom properties), sheet-json, patch (literal → value list), tokens-css / tokens-json / tailwind / shadcn (the --k-* design tokens), swift, android-xml, android-kotlin.

• load

  Load a BUILT web app (a zip of its dist/build/out folder, or a repo zip carrying the build) by URL or local path. Returns the project id, screens, tokenised values and the baseline the knobs stand on. Refuses what cannot render (iOS/Android/source-only) with the reason.

• open

  Open UISandbox in the user's browser with this project loaded — the real, interactive sandbox: the whole app rendered 1:1, every knob there to turn by hand. Use this whenever the user wants to SEE or PLAY with the design themselves ("can I look at this in a sandbox", "let me try some changes"), not only read numbers. Served from 127.0.0.1 by this process; nothing leaves the machine. What the user

• screens

  The screens (HTML entries) of a loaded project.

• screenshot

  A PNG of the screen as it renders with the current knobs (the sandbox frame only).

• set

  Apply knobs to a loaded project. Every dial has ×1 (or 0) = as in their code; colours are #rrggbb. Returns what moved (count and a sample of value → value).

• state

  The knobs as they stand now — including what the user turned by hand in an opened sandbox (and when).

• verifywrite action

  Run the 1:1 check in a real browser: the untouched build vs. the tokenised build with the identity sheet, computed styles of every element diffed. Also returns the reach meter. This is the same check a visitor runs on uisandbox.org.

• Code scan4 source files scanned20/25
• –Live reliabilityno gateway calls yet and no remote to proben/a
• –Tool poisoningtools not inspected (local package is not executed); not countedn/a
• Auth qualitylocal package, no credentials required12/15
• Maintenancelast push 21 days ago15/15
• Maintainer identityregistry namespace matches repository owner7/10

UISandbox: common questions

Is UISandbox MCP server safe?

Mostly: it is graded B (83/100). Read the UISandbox safety report

How do I install UISandbox?

It runs on your machine. Copy the Claude Code, Claude Desktop or Cursor config from the install section.

Does UISandbox need an API key?

No secret keys are declared. It reads 1 setting from the environment.

Is UISandbox maintained?

The last commit was 21 days ago (2026-08-30). The latest release is v0.3.3.

What can I use instead of UISandbox?

Servers from other publishers that do the same job: Loadster MCP server, SeleniumBase MCP server and AIHawk MCP server. Compare all UISandbox alternatives.