synapse init — scaffold new MCP apps with UI

[mgoldsborough]

Summary

Add a npx @nimblebrain/synapse init <name> command that scaffolds a complete MCP app project with a UI.

Motivation

Today, building an MCP app with a Synapse UI requires manually creating ~10 files across two project roots (server + UI). The hello app is the reference, but copy-pasting and renaming is tedious and error-prone.

Proposed UX

npx @nimblebrain/synapse init my-app
# or
npx @nimblebrain/synapse init my-app --python   # default
npx @nimblebrain/synapse init my-app --typescript

Interactive prompts for anything not specified via flags:

• App name (kebab-case, used for package name + manifest)
• Server language (Python or TypeScript)
• Description

Generated structure

my-app/
├── manifest.json
├── pyproject.toml          # or package.json for TS
├── Makefile
├── .mcpbignore
├── .github/workflows/release.yml
├── src/mcp_my_app/         # or src/ for TS
│   ├── __init__.py
│   ├── server.py
│   └── ui.py
└── ui/
    ├── package.json
    ├── vite.config.ts
    ├── tsconfig.json
    ├── index.html
    └── src/
        ├── main.tsx
        └── App.tsx          # SynapseProvider + useCallTool example

Details

• manifest.json — pre-filled with name, one example tool, ui:// resource, _meta for NB platform
• vite.config.ts — react + viteSingleFile + synapseVite() (zero-config)
• App.tsx — working example with useCallTool, useDataSync, useTheme
• server.py / server.ts — example tool + load_ui() pattern
• Makefile — make dev, make build, make bump
• .github/workflows/release.yml — UI build + mcpb-pack
• Post-scaffold message: "Run cd my-app/ui && npm install && npm run dev to start"

Acceptance criteria

• npx @nimblebrain/synapse init my-app creates all files
• cd my-app/ui && npm install && npm run dev works immediately (preview at /__preview)
• cd my-app && uv sync && uv run python -m mcp_my_app.server works (stdio mode)
• Generated app has a working tool call from the UI
• Python and TypeScript templates