fix: advertise JSON Schema 2020-12 in tools/list

.claude-plugin/marketplace.json

@@ -6,14 +6,14 @@
   },
   "metadata": {
     "description": "Official Perplexity AI plugin providing real-time web search, reasoning, and research capabilities",
-    "version": "1.2.0"
+    "version": "1.2.1"
   },
   "plugins": [
     {
       "name": "perplexity",
       "source": "./",
       "description": "Real-time web search, reasoning, and research through Perplexity's API",
-      "version": "1.2.0",
+      "version": "1.2.1",
       "author": {
         "name": "Perplexity AI",
         "email": "api@perplexity.ai"

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@perplexity-ai/mcp-server",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "mcpName": "ai.perplexity/mcp-server",
   "description": "Real-time web search, reasoning, and research through Perplexity's API",
   "keywords": [

plugin.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://agent-plugins.org/schemas/1.0.0/plugin.schema.json",
   "name": "perplexity",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "Real-time web search, reasoning, and research through Perplexity's API",
   "author": {
     "name": "Perplexity AI",

server.json

@@ -3,12 +3,12 @@
   "name": "ai.perplexity/mcp-server",
   "title": "Perplexity API Platform",
   "description": "Real-time web search, reasoning, and research through Perplexity's API",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "packages": [
     {
       "registryType": "npm",
       "identifier": "@perplexity-ai/mcp-server",
-      "version": "1.2.0",
+      "version": "1.2.1",
       "transport": {
         "type": "stdio"
       }

src/index.test.ts

@@ -127,9 +127,9 @@ describe("Perplexity MCP Server", () => {
           headers: {
             "Content-Type": "application/json",
             Authorization: "Bearer test-api-key",
-            "User-Agent": "perplexity-mcp/1.2.0",
+            "User-Agent": "perplexity-mcp/1.2.1",
             "X-Source": "pplx-mcp-server",
-            "X-Pplx-Integration": "perplexity-mcp/1.2.0",
+            "X-Pplx-Integration": "perplexity-mcp/1.2.1",
           },
           body: JSON.stringify({
             preset: "fast",

src/server.test.ts

@@ -366,3 +366,31 @@ describe("Server Utility Functions", () => {
     });
   });
 });
+
+describe("createPerplexityServer tools/list schemas", () => {
+  it("advertises JSON Schema 2020-12 on every input and output schema", async () => {
+    vi.stubEnv("PERPLEXITY_API_KEY", "pplx-test");
+    const { Client } = await import("@modelcontextprotocol/sdk/client/index.js");
+    const { InMemoryTransport } = await import("@modelcontextprotocol/sdk/inMemory.js");
+    const { createPerplexityServer } = await import("./server.js");
+
+    const server = createPerplexityServer();
+    const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
+    await server.connect(serverTransport);
+    const client = new Client({ name: "test", version: "0.0.0" });
+    await client.connect(clientTransport);
+
+    const { tools } = await client.listTools();
+    expect(tools.length).toBeGreaterThan(0);
+    for (const tool of tools) {
+      expect(tool.inputSchema.$schema, `${tool.name} inputSchema`).toBe(
+        "https://json-schema.org/draft/2020-12/schema"
+      );
+      expect(tool.outputSchema?.$schema, `${tool.name} outputSchema`).toBe(
+        "https://json-schema.org/draft/2020-12/schema"
+      );
+    }
+    await client.close();
+    await server.close();
+  });
+});

src/server.ts

@@ -18,7 +18,7 @@ export type { ApiKeyProvider, PerplexityServerOptions } from "./types.js";
 
 const PERPLEXITY_API_KEY = process.env.PERPLEXITY_API_KEY;
 const PERPLEXITY_BASE_URL = process.env.PERPLEXITY_BASE_URL || "https://api.perplexity.ai";
-const VERSION = "1.2.0";
+const VERSION = "1.2.1";
 
 // Agent API presets backing each tool: https://docs.perplexity.ai/docs/agent-api/presets
 export const ASK_PRESET = "fast";
@@ -776,5 +776,42 @@ export function createPerplexityServer(serviceOrigin?: string, serverOptions?: P
     }
   );
 
+  advertiseJsonSchema202012(server.server);
+
   return server.server;
 }
+
+// The MCP TypeScript SDK stamps draft-07 on tools/list schemas
+// (modelcontextprotocol/typescript-sdk#2084); 2020-12-only clients reject
+// them. The schemas are valid under both dialects, so only the declared
+// dialect needs rewriting. Remove once typescript-sdk#2085 ships.
+const JSON_SCHEMA_2020_12 = "https://json-schema.org/draft/2020-12/schema";
+
+function advertiseJsonSchema202012(server: McpServer["server"]) {
+  type ListToolsHandler = (request: unknown, extra: unknown) => Promise<{
+    tools: Array<{
+      inputSchema?: { $schema?: string };
+      outputSchema?: { $schema?: string };
+    }>;
+  }>;
+  // _requestHandlers is private SDK state; goes away with this shim.
+  const handlers = (server as unknown as {
+    _requestHandlers: Map<string, ListToolsHandler>;
+  })._requestHandlers;
+  const listTools = handlers.get("tools/list");
+  if (!listTools) {
+    return;
+  }
+  handlers.set("tools/list", async (request, extra) => {
+    const result = await listTools(request, extra);
+    for (const tool of result.tools ?? []) {
+      if (tool.inputSchema?.$schema) {
+        tool.inputSchema.$schema = JSON_SCHEMA_2020_12;
+      }
+      if (tool.outputSchema?.$schema) {
+        tool.outputSchema.$schema = JSON_SCHEMA_2020_12;
+      }
+    }
+    return result;
+  });
+}