mcp-lucene-server

import { Server } from "@modelcontextprotocol/sdk/server/index.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { ListToolsRequestSchema, CallToolRequestSchema } from "@modelcontextprotocol/sdk/types.js"; import axios from "axios"; const LUCENE_BASE_URL = process.env.LUCENE_BASE_URL || "http://localhost:8080/mcp/v1"; const FORCE_TEXT = process.env.MCP_FORCE_TEXT === "1" || process.env.MCP_FORCE_TEXT === "true"; function toMcpContent(res) { const contentType = res.headers?.["content-type"] || ""; const isJson = contentType.includes("application/json"); const body = res.data; // Debug to stderr for troubleshooting console.error("[shim] content-type:", contentType, "type:", typeof body, "forceText:", FORCE_TEXT); const pretty = typeof body === "string" ? body : JSON.stringify(body, null, 2); if (FORCE_TEXT) { return { content: [{ type: "text", text: pretty }] }; } if (isJson || typeof body === "object") { return { content: [ { type: "json", json: body }, { type: "text", text: pretty } ] }; } return { content: [{ type: "text", text: pretty }] }; } const tools = [ { name: "lucene_status", description: "Get status of the Lucene MCP server (index path, doc count).", inputSchema: { type: "object", properties: {} } }, { name: "lucene_upsert", description: "Upsert documents into Lucene index.", inputSchema: { type: "object", required: ["documents"], properties: { documents: { type: "array", items: { type: "object", required: ["id", "text"], properties: { id: { type: "string" }, text: { type: "string" }, metadata: { type: "object", additionalProperties: { type: "string" } } } } } } } }, { name: "lucene_query", description: "Query Lucene index with optional metadata filter and top_k.", inputSchema: { type: "object", required: ["queries"], properties: { queries: { type: "array", items: { type: "object", required: ["query"], properties: { query: { type: "string" }, top_k: { type: "number" }, filter: { type: "object", additionalProperties: { type: "string" } } } } } } } }, { name: "lucene_delete", description: "Delete documents by ids.", inputSchema: { type: "object", required: ["ids"], properties: { ids: { type: "array", items: { type: "string" } } } } }, { name: "lucene_list", description: "List documents with pagination (limit, offset).", inputSchema: { type: "object", properties: { limit: { type: "number", default: 10 }, offset: { type: "number", default: 0 } } } } ]; const server = new Server( { name: "mcp-lucene-shim", version: "0.1.0" }, { capabilities: { tools: {} } } ); server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: tools.map(t => ({ name: t.name, description: t.description, inputSchema: t.inputSchema })) })); server.setRequestHandler(CallToolRequestSchema, async (req) => { const { name, arguments: args } = req.params; try { switch (name) { case "lucene_status": { const res = await axios.get(`${LUCENE_BASE_URL}/status`); return toMcpContent(res); } case "lucene_upsert": { const res = await axios.post(`${LUCENE_BASE_URL}/upsert`, args); return toMcpContent(res); } case "lucene_query": { const res = await axios.post(`${LUCENE_BASE_URL}/query`, args); return toMcpContent(res); } case "lucene_delete": { const res = await axios.post(`${LUCENE_BASE_URL}/delete`, args); return toMcpContent(res); } case "lucene_list": { const limit = args?.limit ?? 10; const offset = args?.offset ?? 0; const res = await axios.get(`${LUCENE_BASE_URL}/list`, { params: { limit, offset } }); return toMcpContent(res); } default: throw new Error(`Unknown tool: ${name}`); } } catch (err) { const status = err?.response?.status; const data = err?.response?.data; console.error("[shim] error status:", status, "payload type:", typeof data); if (FORCE_TEXT) { const text = typeof data === "string" ? data : JSON.stringify(data ?? { error: err?.message || "Unknown error" }, null, 2); return { content: [{ type: "text", text }] }; } if (typeof data === "object") { return { content: [{ type: "json", json: data }] }; } const text = typeof data === "string" ? data : (err?.message || "Unknown error"); return { content: [{ type: "text", text }] }; } }); const transport = new StdioServerTransport(); await server.connect(transport); console.error("mcp-lucene-shim running (STDIO), forwarding to:", LUCENE_BASE_URL, "forceText:", FORCE_TEXT);