Claude generates structured BuildPlan JSON. Plinth queues it in your Webflow CMS. Your Designer Extension builds it — section by section, without a single fragile API call.
Why Plinth
Direct MCP→Designer connections are fragile. Tabs lose focus. Calls time out. Webflow's live API doesn't tolerate interruptions mid-build.
Plinth decouples generation from execution. Claude describes a section as JSON. The queue persists it. The extension builds it — reliably, on its own schedule.
How it works
01
Claude generates a BuildPlan
You describe a page section in natural language. Claude generates a structured BuildPlan JSON — element tree, styles, CSS properties — all validated against a strict schema.
02
Queued in Webflow CMS
The MCP relay server writes the plan to a _Build Queue CMS collection. It persists safely until the Designer Extension is ready to process it.
03
Extension builds it
The Designer Extension polls the queue, picks up pending plans, and materializes every element — styles, hierarchy, attributes — directly onto the Webflow canvas.
BuildPlan format
Get started
STEP 01
Install the CLI
npm install -g plinth
Installs the plinth command globally. Requires Node 18+.
STEP 02
Initialise your project
cd my-webflow-project
plinth init
Prompts for your Webflow API token, discovers your site, creates the _Build Queue CMS collection, and registers the MCP server with Claude Code.
STEP 03
Start the relay server
plinth server
Starts the HTTP relay on localhost:3847. Claude Code's MCP tools route through here to your Webflow site.
STEP 04
Install the Designer Extension
cd extension && npm run dev
Run the extension dev server, then register it in Webflow Dashboard → Workspace Settings → Apps & Integrations → Develop. Open your site in Designer and start building.