feat: migrate search to support Tavily as configurable provider

.env.example

@@ -1,3 +1,8 @@
 PORT=3100
 API_KEYS=your-api-key-1,your-api-key-2
 NODE_ENV=production
+
+# Search provider: "duckduckgo" (default) or "tavily"
+SEARCH_PROVIDER=duckduckgo
+# Required when SEARCH_PROVIDER=tavily
+TAVILY_API_KEY=

package.json

@@ -31,6 +31,7 @@
     "@hono/node-server": "^1.19.9",
     "@modelcontextprotocol/sdk": "^1.27.1",
     "@mozilla/readability": "^0.6.0",
+    "@tavily/core": "^0.6.4",
     "@types/better-sqlite3": "^7.6.13",
     "@types/jsdom": "^28.0.0",
     "@types/node": "^25.3.3",

src/mcp-server.ts

@@ -1,7 +1,7 @@
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import { z } from "zod";
-import { searchDuckDuckGo } from "./services/search.js";
+import { search } from "./services/search.js";
 import { extractContent } from "./services/extract.js";
 import { getWeather } from "./services/weather.js";
 import { getStockQuote, getExchangeRate } from "./services/finance.js";
@@ -15,14 +15,14 @@ const server = new McpServer({
 // Search tool
 server.tool(
   "search",
-  "Search the web using DuckDuckGo",
+  "Search the web (DuckDuckGo or Tavily depending on SEARCH_PROVIDER)",
   {
     query: z.string().describe("Search query"),
     count: z.number().min(1).max(10).default(5).describe("Number of results"),
     lang: z.string().default("en").describe("Language code"),
   },
   async ({ query, count, lang }) => {
-    const results = await searchDuckDuckGo({ query, count, lang });
+    const results = await search({ query, count, lang });
     return {
       content: [{ type: "text" as const, text: JSON.stringify(results, null, 2) }],
     };

src/mcp-sse.ts

@@ -3,7 +3,7 @@ import { SSEServerTransport } from "@modelcontextprotocol/sdk/server/sse.js";
 import { z } from "zod";
 import type { IncomingMessage, ServerResponse } from "node:http";
 
-import { searchDuckDuckGo } from "./services/search.js";
+import { search } from "./services/search.js";
 import { extractContent } from "./services/extract.js";
 import { getWeather } from "./services/weather.js";
 import { getStockQuote, getExchangeRate } from "./services/finance.js";
@@ -28,10 +28,10 @@ function createMcpServer(): McpServer {
 
   server.tool(
     "search",
-    "Search the web using DuckDuckGo",
+    "Search the web (DuckDuckGo or Tavily depending on SEARCH_PROVIDER)",
     { query: z.string(), count: z.number().min(1).max(10).default(5), lang: z.string().default("en") },
     async ({ query, count, lang }) => ({
-      content: [{ type: "text" as const, text: JSON.stringify(await searchDuckDuckGo({ query, count, lang }), null, 2) }],
+      content: [{ type: "text" as const, text: JSON.stringify(await search({ query, count, lang }), null, 2) }],
     })
   );
 

src/routes/search.ts

@@ -1,5 +1,5 @@
 import { Hono } from "hono";
-import { searchDuckDuckGo } from "../services/search.js";
+import { search } from "../services/search.js";
 import { successResponse, errorResponse } from "../utils/response.js";
 import { requireString, optionalNumber, optionalString } from "../utils/validation.js";
 
@@ -15,7 +15,7 @@ searchRouter.post("/v1/search", async (c) => {
     const count = optionalNumber(body.count, 5, 1, 10);
     const lang = optionalString(body.lang, "en");
 
-    const results = await searchDuckDuckGo({ query, count, lang });
+    const results = await search({ query, count, lang });
     return c.json(successResponse(results, endpoint, startTime));
   } catch (err) {
     const message = err instanceof Error ? err.message : "Search failed";

src/services/search.ts

@@ -1,3 +1,5 @@
+import { tavily } from "@tavily/core";
+
 export interface SearchResult {
   title: string;
   url: string;
@@ -10,6 +12,34 @@ export interface SearchInput {
   lang?: string;
 }
 
+/**
+ * Provider-aware search dispatch.
+ * Uses Tavily when SEARCH_PROVIDER=tavily and TAVILY_API_KEY is set,
+ * otherwise falls back to DuckDuckGo.
+ */
+export async function search(input: SearchInput): Promise<SearchResult[]> {
+  const provider = (process.env.SEARCH_PROVIDER || "duckduckgo").toLowerCase();
+  if (provider === "tavily" && process.env.TAVILY_API_KEY) {
+    return searchTavily(input);
+  }
+  return searchDuckDuckGo(input);
+}
+
+export async function searchTavily(input: SearchInput): Promise<SearchResult[]> {
+  const { query, count = 5 } = input;
+  const client = tavily({ apiKey: process.env.TAVILY_API_KEY! });
+  const response = await client.search(query, {
+    maxResults: count,
+    searchDepth: "basic",
+    topic: "general",
+  });
+  return (response.results || []).map((r: { title: string; url: string; content: string }) => ({
+    title: r.title,
+    url: r.url,
+    snippet: r.content,
+  }));
+}
+
 export async function searchDuckDuckGo(input: SearchInput): Promise<SearchResult[]> {
   const { query, count = 5, lang = "en" } = input;