stitch-mcp

A Go MCP server that proxies Google Stitch API calls with resilient screen generation. It handles authentication, token refresh, and automatic recovery from connection drops during long-running screen generation requests.

Features

• Dynamic tool discovery — Fetches available tools from the Stitch API at startup
• Resilient screen generation — Automatically recovers from TCP connection drops (common during 2-10 min generation requests) by polling for new screens
• Automatic authentication — Uses gcloud Application Default Credentials with background token refresh and 401 retry
• Generation tracking — Virtual tools (generation_status, list_generations) provide visibility into in-flight work
• STDIO transport — Works with any MCP client (Claude Code, Claude Desktop, etc.)

How It Works

Screen generation (generate_screen_from_text) takes 2-10 minutes and the Stitch API frequently drops the TCP connection after ~60 seconds. The proxy handles this transparently:

1. Snapshot existing screens via list_screens
2. Fire the generation request (may succeed directly or connection may drop)
3. Poll list_screens on connection drop until a new screen appears
4. Return the new screen details to the client as if nothing happened

Prerequisites

• Go 1.23+
• gcloud CLI authenticated:

gcloud auth application-default login

Installation

go install github.com/obinnaokechukwu/stitch-mcp@latest

Or build from source:

git clone https://github.com/obinnaokechukwu/stitch-mcp.git
cd stitch-mcp
go build -o stitch-mcp .

Configuration

Environment Variable	Description	Default
STITCH_API_KEY	API key (skips OAuth if set)	—
STITCH_HOST	Stitch API endpoint	https://stitch.googleapis.com/mcp
STITCH_PROJECT_ID	GCP project for billing	Auto-detected from gcloud
STITCH_DEBUG	Enable debug logging (1)	0

Usage with Claude Code

Add to your MCP settings (~/.claude/settings.json):

{
  "mcpServers": {
    "stitch": {
      "command": "stitch-mcp",
      "env": {
        "STITCH_DEBUG": "1"
      }
    }
  }
}

Available Tools

From Stitch API (discovered dynamically):

• create_project — Create a new Stitch project
• list_projects — List accessible projects
• get_project — Get project details
• list_screens — List screens in a project
• get_screen — Get screen details
• generate_screen_from_text — Generate a UI screen from a text prompt (resilient)

Virtual tools (proxy-only):

• generation_status — Check status of a screen generation by ID
• list_generations — List all in-flight and recent generations

License

Apache 2.0 — see LICENSE