fix(mcp): return empty search results as successful collection instead of error (#414)

examples/mcp-server/README.md

@@ -103,9 +103,10 @@ JSON):
 ### What each tool does
 
 - `bazaar_search` — searches a Bazaar node's discovery endpoint. Takes `url`
-  (base URL of the Bazaar API) and an optional `query`. Returns the catalog of
-  discoverable resources, or a structured error such as `ERR_NO_RESULTS` or
-  `ERR_SERVICE_UNREACHABLE`.
+  (base URL of the Bazaar API) and an optional `query`. Returns the collection of
+  discoverable resources and count (or `{ resources: [], count: 0 }` when no matching
+  resources exist, distinguishing empty matches from unreachable services), or a structured
+  error such as `ERR_SERVICE_UNREACHABLE` or `ERR_URL_BLOCKED`.
 - `paid_call` — makes a paid API call to a Bazaar resource, handling the x402
   402 payment loop automatically. Takes `url` (full URL of the resource) and an
   optional `method` (default `GET`). Returns the resource body, or a structured

src/mcp/server.ts

@@ -225,12 +225,13 @@ export class BazaarMcpServer {
           const hasResources = (d: unknown): d is { resources: unknown[] } => 
             typeof d === 'object' && d !== null && 'resources' in d && Array.isArray((d as Record<string, unknown>).resources);
 
-          if ((Array.isArray(data) && data.length === 0) || (hasResources(data) && data.resources.length === 0)) {
-            return this.createErrorResponse('ERR_NO_RESULTS', 'No resources found');
-          }
+          const rawList = Array.isArray(data) ? data : (hasResources(data) ? data.resources : []);
+          const resultPayload = typeof data === 'object' && data !== null && !Array.isArray(data)
+            ? { ...data, resources: rawList, count: rawList.length }
+            : { resources: rawList, count: rawList.length };
 
           return {
-            content: [{ type: 'text', text: JSON.stringify(data, null, 2) }],
+            content: [{ type: 'text', text: JSON.stringify(resultPayload, null, 2) }],
           };
         } catch (e: any) {
           if (e instanceof SsrfError) {

tests/mcp.test.ts

@@ -217,6 +217,37 @@ describe('BazaarMcpServer bazaar_search SSRF guard (#407)', () => {
     expect(response.isError).toBeFalsy();
     expect(JSON.parse(response.content[0].text).resources[0].name).toBe('x');
   });
+
+  it('returns success with empty collection when bazaar_search finds no resources (#414)', async () => {
+    const emptyFetchImpl = async () =>
+      new Response(JSON.stringify({ resources: [] }), { status: 200, headers: { 'content-type': 'application/json' } });
+    const server = new BazaarMcpServer({
+      fetchWithPayment: vi.fn(),
+      bazaarFetch: { allowedHosts: [], ...publicLookup, fetchImpl: emptyFetchImpl },
+    });
+    const handler = captureHandler(server);
+    const response = await handler({ params: { name: 'bazaar_search', arguments: { url: 'https://ok.example', query: 'nonexistent' } } });
+    expect(response.isError).toBeFalsy();
+    const payload = JSON.parse(response.content[0].text);
+    expect(payload.resources).toEqual([]);
+    expect(payload.count).toBe(0);
+  });
+
+  it('returns success with empty collection when endpoint returns empty array (#414)', async () => {
+    const emptyArrayFetchImpl = async () =>
+      new Response(JSON.stringify([]), { status: 200, headers: { 'content-type': 'application/json' } });
+
+    const server = new BazaarMcpServer({
+      fetchWithPayment: vi.fn(),
+      bazaarFetch: { allowedHosts: [], ...publicLookup, fetchImpl: emptyArrayFetchImpl },
+    });
+    const handler = captureHandler(server);
+    const response = await handler({ params: { name: 'bazaar_search', arguments: { url: 'https://ok.example' } } });
+    expect(response.isError).toBeFalsy();
+    const payload = JSON.parse(response.content[0].text);
+    expect(payload.resources).toEqual([]);
+    expect(payload.count).toBe(0);
+  });
 });
 
 describe('BazaarMcpServer argument validation (#411)', () => {
@@ -483,3 +514,4 @@ describe('BazaarMcpServer bazaar_search upstream failures (#349)', () => {
     expect(body.reason).toContain('not valid JSON');
   });
 });
+