claude-design-mcp

Unofficial stdio MCP proxy for Anthropic’s Claude Design MCP
(https://api.anthropic.com/v1/design/mcp).

Works with Cursor, Claude Code, Codex, and any MCP host that can launch a local stdio server.

Not affiliated with Anthropic. Claude Design’s public MCP OAuth discovery is currently broken for generic clients. This tool uses the same Design OAuth login flow as Claude Code’s /design-login (including Anthropic’s Design OAuth client id). Anthropic may change or revoke that flow.

Quick start

1. Login once

npx -y github:erdnj/claude-design-mcp login

Replace erdnj with this repository’s GitHub user or org. Approve in the browser, then paste the full CODE#STATE value.

2. Add the MCP server

Cursor / Claude Code — .cursor/mcp.json or .mcp.json:

{
  "mcpServers": {
    "claude-design": {
      "command": "npx",
      "args": ["-y", "github:erdnj/claude-design-mcp"]
    }
  }
}

Codex — ~/.codex/config.toml:

[mcp_servers.claude-design]
command = "npx"
args = ["-y", "github:erdnj/claude-design-mcp"]
enabled = true

Reload MCP / restart the agent. No Connect button is needed; the proxy injects your Design token.

After clone, npx -y . snippets prints ready-to-paste configs using this package’s repository field.

Commands

Command	Purpose
(default) / server	Start MCP stdio proxy
login	Browser OAuth + paste CODE#STATE
status	Credential status
token	Print access token (auto-refresh)
env	export CLAUDE_DESIGN_OAUTH_TOKEN=…
logout	Delete stored credentials
snippets	Print install snippets

Credentials are stored at:

~/.config/claude-design-mcp/credentials.json

Override path with CLAUDE_DESIGN_MCP_CREDENTIALS.

How it works

1. login runs Anthropic’s Design OAuth (PKCE, manual redirect).
2. Tokens are saved locally and refreshed when needed.
3. The MCP server proxies stdio ↔ https://api.anthropic.com/v1/design/mcp with Authorization: Bearer <design-token>.

Requirements

• Node.js 20+
• A Claude account with Claude Design access (Pro / Max / Team / Enterprise, as applicable)

Disclaimer

Community workaround for multi-agent use. Prefer Anthropic’s official connector when it supports third-party MCP clients properly.