Polyxd — Claude Code MCP server: what it does, how to install
Lets models build Polyxd UI documents, validates their structure, and renders live screens inside MCP-compatible clients.
claude mcp add --transport http mcp https://mcp.polyxd.com/mcpWhat Polyxd does
The server equips the host model with the Polyxd component specification through polyxd_guide. When the model writes screen layouts, polyxd_validate detects schema mistakes and returns JSON Pointer paths with actionable hints. Audits run via polyxd_verify without pulling in Playwright binaries.
For visual output, polyxd_show hands the document to a sandboxed iframe using the MCP Apps standard. The default design pack is material3, while polyxd_packs lets users inspect other supported themes. When you click a button or submit an action in the rendered screen, the frame dispatches a ui/message back to the model with form inputs and action metadata.
If your client lacks MCP Apps support, the server outputs a plain text summary instead of an interactive view. Any validation error blocks the screen from displaying until resolved.
What it helps with
- prototype interactive interfaces directly inside the agent chat
- validate Polyxd JSON layout against the component schema
- render screens across design system packs like material3
- pass button clicks and form inputs back to the model context
Example prompts for the agent
- Read the Polyxd guide and build a user profile settings screen
- Validate this screen layout and fix pointer warnings
- Render the document using polyxd_show with the dark theme
How to install Polyxd
1Platform CLI: remote server
claude mcp add --transport http mcp https://mcp.polyxd.com/mcp2Platform CLI
claude mcp add mcp -- npx -y @polyxd/mcp1Platform CLI: remote server
codex mcp add mcp --url https://mcp.polyxd.com/mcp2Platform CLI
codex mcp add mcp -- npx -y @polyxd/mcpConfig file
{
"mcpServers": {
"mcp": {
"url": "https://mcp.polyxd.com/mcp"
}
}
}{
"mcpServers": {
"mcp": {
"command": "npx",
"args": [
"-y",
"@polyxd/mcp"
]
}
}
}Config file
{
"servers": {
"mcp": {
"type": "http",
"url": "https://mcp.polyxd.com/mcp"
}
}
}{
"servers": {
"mcp": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"@polyxd/mcp"
]
}
}
}1Platform CLI: remote server
gemini mcp add -t http mcp https://mcp.polyxd.com/mcp2Platform CLI
gemini mcp add mcp npx -y @polyxd/mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about Polyxd
How do I install Polyxd in Claude Code?
Run claude mcp add --transport http mcp https://mcp.polyxd.com/mcp for the hosted HTTP server. For a local stdio connection, run claude mcp add mcp -- npx -y @polyxd/mcp.
What does Polyxd MCP server do?
It provides component rules to the language model, checks layout markup for schema issues, and renders screens in sandboxed frames.
Does Polyxd require Playwright for audits?
No, polyxd_verify executes static checks from @polyxd/verifier/static, avoiding browser automation binaries entirely.
