refactor: share mcp api calls

packages/mcp-server/src/protocol/handler.ts

@@ -2,7 +2,30 @@ import { logger } from "../logger";
 import { tools } from "./tools";
 
 const API_BASE_URL = process.env.API_BASE_URL || "http://localhost:4005/api";
-const API_TIMEOUT = Number(process.env.API_TIMEOUT) || 180000; // 3 minutes default
+const API_TIMEOUT = Number(process.env.API_TIMEOUT) || 180000;
+
+async function callMarketplaceApi(
+  marketplace: string,
+  params: URLSearchParams,
+): Promise<unknown> {
+  const url = `${API_BASE_URL}/${marketplace}?${params.toString()}`;
+  logger.log(`[MCP] Calling ${marketplace} API`);
+  const response = await Promise.race([
+    fetch(url),
+    new Promise<Response>((_, reject) =>
+      setTimeout(
+        () => reject(new Error(`Request timed out after ${API_TIMEOUT}ms`)),
+        API_TIMEOUT,
+      ),
+    ),
+  ]);
+  if (!response.ok) {
+    const errorText = await response.text();
+    logger.error(`[MCP] ${marketplace} API error ${response.status}: ${errorText}`);
+    throw new Error(`API returned ${response.status}: ${errorText}`);
+  }
+  return response.json();
+}
 
 /**
  * Handle MCP JSON-RPC 2.0 protocol requests
@@ -119,31 +142,7 @@ export async function handleMcpRequest(req: Request): Promise<Response> {
           if (args.unstableFilter !== undefined)
             params.append("unstableFilter", args.unstableFilter.toString());
 
-          logger.log(
+          result = await callMarketplaceApi("kijiji", params);
-            `[MCP] Calling Kijiji API: ${API_BASE_URL}/kijiji?${params.toString()}`,
-          );
-          const response = await Promise.race([
-            fetch(`${API_BASE_URL}/kijiji?${params.toString()}`),
-            new Promise<Response>((_, reject) =>
-              setTimeout(
-                () =>
-                  reject(new Error(`Request timed out after ${API_TIMEOUT}ms`)),
-                API_TIMEOUT,
-              ),
-            ),
-          ]);
-
-          if (!response.ok) {
-            const errorText = await response.text();
-            logger.error(
-              `[MCP] Kijiji API error ${response.status}: ${errorText}`,
-            );
-            throw new Error(`API returned ${response.status}: ${errorText}`);
-          }
-          result = await response.json();
-          logger.log(
-            `[MCP] Kijiji returned ${Array.isArray(result) ? result.length : 0} items`,
-          );
         } else if (name === "search_facebook") {
           const query = args.query;
           if (!query) {
@@ -160,31 +159,7 @@ export async function handleMcpRequest(req: Request): Promise<Response> {
           if (args.unstableFilter !== undefined)
             params.append("unstableFilter", args.unstableFilter.toString());
 
-          logger.log(
+          result = await callMarketplaceApi("facebook", params);
-            `[MCP] Calling Facebook API: ${API_BASE_URL}/facebook?${params.toString()}`,
-          );
-          const response = await Promise.race([
-            fetch(`${API_BASE_URL}/facebook?${params.toString()}`),
-            new Promise<Response>((_, reject) =>
-              setTimeout(
-                () =>
-                  reject(new Error(`Request timed out after ${API_TIMEOUT}ms`)),
-                API_TIMEOUT,
-              ),
-            ),
-          ]);
-
-          if (!response.ok) {
-            const errorText = await response.text();
-            logger.error(
-              `[MCP] Facebook API error ${response.status}: ${errorText}`,
-            );
-            throw new Error(`API returned ${response.status}: ${errorText}`);
-          }
-          result = await response.json();
-          logger.log(
-            `[MCP] Facebook returned ${Array.isArray(result) ? result.length : 0} items`,
-          );
         } else if (name === "search_ebay") {
           const query = args.query;
           if (!query) {
@@ -214,31 +189,7 @@ export async function handleMcpRequest(req: Request): Promise<Response> {
           if (args.unstableFilter !== undefined)
             params.append("unstableFilter", args.unstableFilter.toString());
 
-          logger.log(
+          result = await callMarketplaceApi("ebay", params);
-            `[MCP] Calling eBay API: ${API_BASE_URL}/ebay?${params.toString()}`,
-          );
-          const response = await Promise.race([
-            fetch(`${API_BASE_URL}/ebay?${params.toString()}`),
-            new Promise<Response>((_, reject) =>
-              setTimeout(
-                () =>
-                  reject(new Error(`Request timed out after ${API_TIMEOUT}ms`)),
-                API_TIMEOUT,
-              ),
-            ),
-          ]);
-
-          if (!response.ok) {
-            const errorText = await response.text();
-            logger.error(
-              `[MCP] eBay API error ${response.status}: ${errorText}`,
-            );
-            throw new Error(`API returned ${response.status}: ${errorText}`);
-          }
-          result = await response.json();
-          logger.log(
-            `[MCP] eBay returned ${Array.isArray(result) ? result.length : 0} items`,
-          );
         } else {
           return Response.json({
             jsonrpc: "2.0",

packages/mcp-server/test/protocol.test.ts

@@ -152,6 +152,33 @@ describe("MCP protocol unstableFilter", () => {
     expect(String(calledUrl)).toContain("unstableFilter=true");
   });
 
+  test("tools/call returns API JSON as text content", async () => {
+    global.fetch = mock(() =>
+      Promise.resolve(
+        new Response(JSON.stringify([{ title: "item" }]), { status: 200 }),
+      ),
+    ) as unknown as typeof fetch;
+
+    const response = await handleMcpRequest(
+      new Request("http://localhost", {
+        method: "POST",
+        body: JSON.stringify({
+          jsonrpc: "2.0",
+          id: 1,
+          method: "tools/call",
+          params: {
+            name: "search_facebook",
+            arguments: { query: "laptop" },
+          },
+        }),
+      }),
+    );
+
+    const body = await response.json();
+    expect(body.result.content[0].type).toBe("text");
+    expect(JSON.parse(body.result.content[0].text)).toEqual([{ title: "item" }]);
+  });
+
   test("handler should forward unstableFilter=true for search_ebay", async () => {
     await handleMcpRequest(
       new Request("http://localhost", {