Enables interaction with Slack, providing tools to manage messages, channels, and workspace communications.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@LeanMCP Minimal Server Show me the list of available products"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
MCP Server with Streamable HTTP Transport built with LeanMCP SDK
# Install dependencies
npm install
# Start development server (hot reload + UI build)
npm run dev
# Build for production
npm run build
# Run production server
npm startRelated MCP server: MyPostmanServer
leanmcp-minimal/
├── main.ts # Server entry point
├── mcp/ # Services directory (auto-discovered)
│ └── example/
│ └── index.ts # Example service
├── .env # Environment variables
└── package.jsonCreate a new service directory in mcp/:
// mcp/myservice/index.ts
import { Tool, SchemaConstraint } from "@leanmcp/core";
// Define input schema
class MyToolInput {
@SchemaConstraint({
description: "Message to process",
minLength: 1
})
message!: string;
}
export class MyService {
@Tool({
description: "My awesome tool",
inputClass: MyToolInput
})
async myTool(input: MyToolInput) {
return {
content: [{
type: "text",
text: `You said: ${input.message}`
}]
};
}
}Services are automatically discovered and registered - no need to modify main.ts!
Use @UIApp decorator to link tools to React components:
// mcp/products/index.ts
import { Tool } from "@leanmcp/core";
import { UIApp } from "@leanmcp/ui";
export class ProductsService {
@Tool({ description: "List products" })
@UIApp({ component: "./ProductsDashboard" })
async listProducts() {
return { products: [...] };
}
}// mcp/products/ProductsDashboard.tsx
import { ToolDataGrid, RequireConnection } from "@leanmcp/ui";
export function ProductsDashboard() {
return (
<RequireConnection loading={<div>Loading...</div>}>
<ToolDataGrid toolName="listProducts" columns={[...]} />
</RequireConnection>
);
}The CLI automatically builds UI components and wraps them with AppProvider.
Zero-config auto-discovery - Services automatically registered from ./mcp directory
Type-safe decorators - @Tool, @Prompt, @Resource with full TypeScript support
Schema validation - Automatic input validation with @SchemaConstraint
HTTP transport - Production-ready HTTP server with session management
Hot reload - Development mode with automatic restart on file changes
UI Components - React UI components with @UIApp decorator
npx @modelcontextprotocol/inspector http://localhost:3001/mcpMIT
This server cannot be deployed
MCP server for progressive tool usage at any scale (see https://klavis.ai)
Lean 4 MCP server: compile, prove theorems, and formalize math with Mathlib.
