LlamaCloud MCP Server
Official
by run-llama
#!/usr/bin/env node
/**
* This is a MCP server that connects to multiple managed indexes on LlamaCloud.
* Each index is exposed as a separate tool.
*/
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import {
CallToolRequestSchema,
ListToolsRequestSchema,
} from "@modelcontextprotocol/sdk/types.js";
import { LlamaCloudIndex, MetadataMode } from "llamaindex";
// Define the tool definition interface
interface ToolDefinition {
indexName: string;
description: string;
toolName?: string;
}
// Parse command line arguments
function parseToolDefinitions(): ToolDefinition[] {
const args = process.argv.slice(2);
if (args.length === 0) {
console.error(
'No tool definitions provided. Use format: --index "IndexName" --description "Description"',
);
process.exit(1);
}
const toolDefinitions: ToolDefinition[] = [];
let currentIndexName: string | null = null;
for (let i = 0; i < args.length; i++) {
if (args[i] === "--index" && i + 1 < args.length) {
// Save the current index name. We'll wait for the description to complete the definition
currentIndexName = args[i + 1].trim();
i++; // Skip the next argument since we consumed it
} else if (
args[i] === "--description" &&
i + 1 < args.length &&
currentIndexName
) {
// We have both an index name and a description, so we can create a tool definition
const description = args[i + 1].trim();
const toolName = `get_information_${currentIndexName.toLowerCase().replace(/[^a-z0-9]/g, "_")}`;
toolDefinitions.push({
indexName: currentIndexName,
description,
toolName,
});
// Reset for the next pair
currentIndexName = null;
i++; // Skip the next argument since we consumed it
}
}
// Check if we have an index without a description at the end
if (currentIndexName) {
console.warn(
`Warning: Index '${currentIndexName}' was specified without a description.`,
);
}
if (toolDefinitions.length === 0) {
console.error(
'No valid tool definitions found. Use format: --index "IndexName" --description "Description"',
);
process.exit(1);
}
return toolDefinitions;
}
/**
* Create an MCP server with capabilities for tools
*/
const server = new Server(
{
name: "llamacloud-mcp-server",
version: "0.1.0",
},
{
capabilities: {
tools: {},
},
},
);
// Get the project name and API key from environment variables
const projectName =
process.env.LLAMA_CLOUD_PROJECT_NAME ||
(() => {
throw new Error("LLAMA_CLOUD_PROJECT_NAME is not set");
})();
const apiKey =
process.env.LLAMA_CLOUD_API_KEY ||
(() => {
throw new Error("LLAMA_CLOUD_API_KEY is not set");
})();
// Parse tool definitions from command line arguments
const toolDefinitions = parseToolDefinitions();
// Create indexes for each tool definition
const indexes = new Map<string, LlamaCloudIndex>();
for (const definition of toolDefinitions) {
const index = new LlamaCloudIndex({
name: definition.indexName,
projectName,
apiKey,
});
indexes.set(definition.toolName!, index);
console.log(
`Created index for tool ${definition.toolName}: ${definition.indexName} - ${definition.description}`,
);
}
/**
* Handler that lists available tools.
* Exposes a tool for each index that lets clients retrieve information.
*/
server.setRequestHandler(ListToolsRequestSchema, async () => {
return {
tools: toolDefinitions.map((definition) => ({
name: definition.toolName!,
description: `Get information from the ${definition.indexName} index. The index contains ${definition.description}`,
inputSchema: {
type: "object",
properties: {
query: {
type: "string",
description: `The query used to get information from the ${definition.indexName} index.`,
},
},
required: ["query"],
},
})),
};
});
/**
* Handler for tool calls.
* Routes requests to the appropriate index based on the tool name.
*/
server.setRequestHandler(CallToolRequestSchema, async (request) => {
const toolName = request.params.name;
const index = indexes.get(toolName);
if (!index) {
throw new Error(`Unknown tool: ${toolName}`);
}
const query = String(request.params.arguments?.query);
if (!query) {
throw new Error("query parameter is required");
}
const retriever = index.asRetriever();
const nodesWithScore = await retriever.retrieve({ query });
const nodes = nodesWithScore.map((node) => node.node);
const context = nodes
.map((r) => r.getContent(MetadataMode.NONE))
.join("\n\n");
return {
content: [
{
type: "text",
text: context,
},
],
};
});
/**
* Start the server using stdio transport.
* This allows the server to communicate via standard input/output streams.
*/
async function main() {
console.log(`Starting MCP server with ${toolDefinitions.length} tools:`);
toolDefinitions.forEach((def) => {
console.log(`- ${def.toolName}: ${def.indexName} - ${def.description}`);
});
const transport = new StdioServerTransport();
await server.connect(transport);
}
main().catch((error) => {
console.error("Server error:", error);
process.exit(1);
});