@densrt/webstudio-mcp

An unofficial MCP server for Webstudio Cloud — generate, push, audit, and refactor Webstudio projects programmatically. Built for AI agents (Claude, Cursor, any MCP-compatible client) and CLI workflows.

Disclaimer. This is an independent, community project. It is not affiliated with, endorsed by, or supported by Webstudio. It drives Webstudio Cloud through a captured browser session (cookie + CSRF), not a public API — behaviour may break if Webstudio changes. Use at your own risk; review SECURITY.md before exposing it to untrusted input.

What it does

• Generate Webstudio fragments (sheets, navs, sections, swipers, popups, custom trees) and push them to a project.
• Audit projects for unused tokens, dead images, oversized fonts, broken bindings, mobile overflow, and more.
• Refactor tokens at scale (rename, replace, dedupe overrides into variants, extract from locals).
• Inspect instances, forms, and resources before patching.
• Safety-first: every mutating action defaults to dryRun, and a two-stage push protocol is enforced server-side.

Requirements

• Node.js ≥ 18
• A Webstudio Cloud account (you capture your own session cookie + CSRF — see docs/auth.md)

Quick start

1. Add the server to your MCP client

No install needed — run it straight from npm with npx.

Claude Code:

claude mcp add webstudio -- npx -y @densrt/webstudio-mcp

Cursor / Claude Desktop (mcpServers block of your client config):

{
  "mcpServers": {
    "webstudio": {
      "command": "npx",
      "args": ["-y", "@densrt/webstudio-mcp"]
    }
  }
}

2. Bootstrap a project

mcp__webstudio__project({ action: "init", label: "init-site", projectSlug: "my-site", webstudioProjectId: "..." })
mcp__webstudio__auth({ action: "setup", label: "auth-site", projectSlug: "my-site", cookie: "...", csrfToken: "..." })
mcp__webstudio__auth({ action: "allow_push", label: "allow-push", projectSlug: "my-site", allow: true })
mcp__webstudio__read({ action: "fetch_pages", label: "list-pages", projectSlug: "my-site" })

See docs/auth.md for how to capture the cookie + CSRF token.

3. Discover tools & patterns

mcp__webstudio__meta({ action: "guide", label: "triage", brief: "desktop mega menu with dropdowns" })   // best pattern + tool
mcp__webstudio__meta({ action: "index", label: "catalog" })                                              // tool catalog
mcp__webstudio__meta({ action: "describe_pattern", label: "doc", pattern: "navigation-menu-radix" })     // full recipe

Architecture

• 15 mega-tools with a discriminated action field (Webflow-MCP-style), instead of a sprawl of atomic tools.
• Required label (3–30 chars, unique within multi-action calls) for result identification.
• Tiered context enforcement: required for CRITICAL actions, recommended for STRUCTURING.
• Annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint) on every tool let MCP clients gate permissions.
• MCP Resources: the pattern library is exposed at webstudio://patterns/<slug>.
• Two-stage push protocol on every mutating action (dryRun:true → forceConfirmed:true).

Deep technical notes live in docs/: data-model.md, auth.md, patches.md, safety.md, plus the pattern recipes under docs/patterns/.

Tool catalog

Mega-tool	Highlights
meta	guide (free-text triage), index, list_patterns, describe_pattern
auth	local credential management (setup, allow_push, update_app_version)
project	init, list, export, nuke (CRITICAL), import_figma
read	fetch_pages, list_instances, read_texts, inspect, snapshot (PNG via Playwright)
pages	create, update, delete, folders, project-level get_meta / update_meta
instances	append, delete, clone, clone_page, wrap, flatten, update_*, prop_*
build	build_fragment, push_fragment, push_complete, create_sheet, create_navigation_menu, create_popup, push_html
styles	get_decls, update, delete_decl, replace_value (local overrides)
tokens	full lifecycle — create, attach, extract, variants, rename, dedupe, …
cssvar	define, list, delete, rewrite_refs
variables	create, list, update, delete, bind_page_field
resources	create, list, update, delete (REST data binding)
assets	upload, list, find_usage, replace, delete
audit	page, overflow, token_usage, orphans, images, fonts, scripts, … (read-only)
cms	external CMS adapter (Directus / WordPress / n8n): list, discover, CRUD, bind_collection_to_instance

Run meta.index for the live, per-action catalog.

Configuration (environment variables)

All optional — the defaults fit interactive agent sessions.

Variable	Default	Effect
WEBSTUDIO_MCP_TOOLS	unset (full surface)	Comma-separated mega-tools to register, e.g. meta,read,audit, or a named preset: readonly (meta,read,audit), content (meta,read,styles,tokens,instances,cms), builder (meta,read,build,instances,styles,tokens). Presets compose with explicit names (readonly,assets). meta is always included. Unknown names warn on stderr; a filter matching nothing fail-safes to meta only. Read-only routines get safety (no mutation tools mounted) + a ~7× cheaper handshake.
WEBSTUDIO_MCP_RESOURCES	unset (enabled)	0 disables the MCP pattern resources (the resources/list, ~6.6 kB per session). Patterns stay reachable via meta.list_patterns / meta.describe_pattern. Recommended for secondary read-only instances: WEBSTUDIO_MCP_TOOLS=readonly + WEBSTUDIO_MCP_RESOURCES=0.
WEBSTUDIO_MCP_BUILD_CACHE_TTL_MS	120000	TTL of the in-memory project-build cache. 0 disables it (every read re-fetches — useful when debugging alongside live edits in the builder).
WEBSTUDIO_MCP_TELEMETRY	unset (off)	1 enables JSONL telemetry (tool calls, coerces, build-cache hit/miss).
WEBSTUDIO_MCP_TELEMETRY_PATH	~/.webstudio-mcp-telemetry.jsonl	Telemetry output path.

From source

git clone https://github.com/Densrt/webstudio-mcp
cd webstudio-mcp
npm install
npm run build
node dist/index.js   # or: claude mcp add webstudio -- node /abs/path/to/dist/index.js

Development

npm run build      # compile TypeScript → dist/
npm test           # run the test suite (node:test)
npm run dev        # watch mode (ts-node)

CI (.github/workflows/mcp-health.yml) runs the build, the full test suite, and a set of guard tests (tool-count cap, description linter, pattern-doc frontmatter, version consistency). See CONTRIBUTING.md.

Contributing

Contributions are welcome — please read CONTRIBUTING.md first. It describes the 4-tier "anti-spaghetti" rule that keeps the tool surface small, and the 8-step workflow for adding an action or pattern.

Security

Found a vulnerability? Please report it privately — see SECURITY.md.

License

MIT