4140565b77
- Add `.gitignore` files to all 19 examples (`node_modules/`, `dist/`) - Replace custom `log` objects with standard `console` methods - Add `ontoolcancelled` handler to all `basic-server-*` examples - Add host styling integration (`applyDocumentTheme`, `applyHostFonts`, `applyHostStyleVariables`) to non-React `basic-server-*` examples - Add section headers for better code organization in feature examples - Update READMEs with Build System section explaining single-file bundling These changes make examples more consistent and easier to adapt. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
36 lines
1.9 KiB
Markdown
36 lines
1.9 KiB
Markdown
# Example: Basic Server (React)
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An MCP App example with a React UI.
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> [!TIP]
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> Looking for a vanilla JavaScript example? See [`basic-server-vanillajs`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-vanillajs)!
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## Overview
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- Tool registration with a linked UI resource
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- React UI using the [`useApp()`](https://modelcontextprotocol.github.io/ext-apps/api/functions/_modelcontextprotocol_ext-apps_react.useApp.html) hook
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- App communication APIs: [`callServerTool`](https://modelcontextprotocol.github.io/ext-apps/api/classes/app.App.html#callservertool), [`sendMessage`](https://modelcontextprotocol.github.io/ext-apps/api/classes/app.App.html#sendmessage), [`sendLog`](https://modelcontextprotocol.github.io/ext-apps/api/classes/app.App.html#sendlog), [`openLink`](https://modelcontextprotocol.github.io/ext-apps/api/classes/app.App.html#openlink)
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## Key Files
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- [`server.ts`](server.ts) - MCP server with tool and resource registration
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- [`mcp-app.html`](mcp-app.html) / [`src/mcp-app.tsx`](src/mcp-app.tsx) - React UI using `useApp()` hook
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## Getting Started
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```bash
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npm install
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npm run dev
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```
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## How It Works
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1. The server registers a `get-time` tool with metadata linking it to a UI HTML resource (`ui://get-time/mcp-app.html`).
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2. When the tool is invoked, the Host renders the UI from the resource.
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3. The UI uses the MCP App SDK API to communicate with the host and call server tools.
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## Build System
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This example bundles into a single HTML file using Vite with `vite-plugin-singlefile` — see [`vite.config.ts`](vite.config.ts). This allows all UI content to be served as a single MCP resource. Alternatively, MCP apps can load external resources by defining [`_meta.ui.csp.resourceDomains`](https://modelcontextprotocol.github.io/ext-apps/api/interfaces/app.McpUiResourceCsp.html#resourcedomains) in the UI resource metadata.
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