Claude Design MCP Integration [Gradual Rollout]

What

A built-in first-party MCP server called claude_design is now available, connecting to Anthropic's Design API at https://api.anthropic.com/v1/design/mcp. When enabled, Claude can mock up UI screens directly in your session. A tip reads "Use Claude Design to mock up screens before you build."

Status

Controlled by feature flag tengu_omelette_whisk. Can also be force-enabled via the environment variable CLAUDE_CODE_ENABLE_DESIGN_MCP=true.

Details

Server name claude_design is treated as first-party — it auto-attaches login OAuth tokens and renders with a bare name (no URL prefix in the UI)
Setting CLAUDE_CODE_ENABLE_DESIGN_MCP=1 bypasses the feature flag for self-hosting or testing

Evidence

Design MCP server name (search for "claude_design") and URL (search for "https://api.anthropic.com/v1/design/mcp")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.179 →

The build it came inv2.1.179

16 Jun 2026 · 23 entries, this one is #1.

Either side of it

v2.1.178Older
v2.1.181Newer

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Names in this entry

flagtengu_omelette_whisk
Default false. On the first-party API provider, adds the built-in claude_design MCP server (HTTP, https://api.anthropic.com/v1/design/mcp) to the dynamic MCP servers. The env var CLAUDE_CODE_ENABLE_DESIGN_MCP takes precedence over this flag when it is set.
envCLAUDE_CODE_ENABLE_DESIGN_MCP
Forces the built-in Claude Design MCP server on (1, true, yes, on) or off (0, false, no, off); unset or any other value falls back to the tengu_omelette_whisk flag, default off. When on and the API provider is first-party, Claude Code adds an HTTP MCP server named claude_design at https://api.anthropic.com/v1/design/mcp to its built-in servers, and it also enables the /design command, which another condition can enable as well.

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