Merge pull request modelcontextprotocol#124 from asklar/user/asklar/static_responses_and_extensions

Add _meta to manifest schema and tests

Author: joan-anthropic

MANIFEST.md

@@ -155,6 +155,54 @@ A full `manifest.json` with most of the optional fields looks like this:
       "min": 1,
       "max": 100
     }
+  },
+  "_meta": {
+    "com.microsoft.windows": {
+      "package_family_name": "MyMcpMSIXPackage_51g09708xawrw",
+      "static_responses": {
+        "initialize": {
+          "capabilities": {},
+          "instructions": "When the user wants to search files, use the search_files tool but only after asking them whether the files are local.",
+          "protocolVersion": "2025-06-18",
+          "serverInfo": {
+            "name": "MyMCPExtension",
+            "title": "My MCP Extension - Pro Edition",
+            "version": "1.0.0"
+          }
+        },
+        "tools/list": {
+          "tools": [
+            {
+              "name": "search_files",
+              "title": "File search",
+              "description": "Search for files in a directory",
+              "inputSchema": {
+                "type": "object",
+                "properties": {
+                  "fileSpec": {
+                    "type": "string",
+                    "description": "The file name to search for. Wildcards are supported"
+                  }
+                },
+                "required": ["fileSpec"]
+              },
+              "outputSchema": {
+                "type": "object",
+                "properties": {
+                  "searchResults": {
+                    "type": "array",
+                    "description": "The list of file paths that were found",
+                    "items": {
+                      "type": "string"
+                    }
+                  }
+                },
+              }
+            }
+          ]
+        }
+      },
+    }
   }
 }
 ```
@@ -189,6 +237,7 @@ A full `manifest.json` with most of the optional fields looks like this:
 - **privacy_policies**: Array of URLs to privacy policies for external services that handle user data. Required when the extension connects to external services (first- or third-party) that process user data. Each URL should link to the respective service's privacy policy document
 - **compatibility**: Compatibility requirements (client app version, platforms, and runtime versions)
 - **user_config**: User-configurable options for the extension (see User Configuration section)
+- **_meta**: Platform-specific client integration metadata (e.g., Windows `package_family_name`, macOS bundle identifiers) enabling tighter OS/app store integration. The keys in the `_meta` object are reverse-DNS namespaced, and the values are a dictionary of platform-specific metadata.
 
 ## Compatibility
 
@@ -606,3 +655,4 @@ The `_generated` fields:
 - **prompts_generated**: Server generates additional prompts beyond those listed (default: false)
 
 This helps implementing apps understand that querying the server at runtime will reveal more capabilities than what's declared in the manifest.
+

src/schemas-loose.ts

@@ -107,6 +107,7 @@ export const McpbManifestSchema = z
     user_config: z
       .record(z.string(), McpbUserConfigurationOptionSchema)
       .optional(),
+    _meta: z.record(z.string(), z.record(z.string(), z.any())).optional(),
   })
   .refine((data) => !!(data.dxt_version || data.manifest_version), {
     message:

src/schemas.ts

@@ -100,7 +100,7 @@ export const McpbManifestSchema = z
     screenshots: z.array(z.string()).optional(),
     server: McpbManifestServerSchema,
     tools: z.array(McpbManifestToolSchema).optional(),
-    tools_generated: z.boolean().optional(),
+    tools_generated: z.boolean().optional(),  
     prompts: z.array(McpbManifestPromptSchema).optional(),
     prompts_generated: z.boolean().optional(),
     keywords: z.array(z.string()).optional(),
@@ -110,6 +110,7 @@ export const McpbManifestSchema = z
     user_config: z
       .record(z.string(), McpbUserConfigurationOptionSchema)
       .optional(),
+    _meta: z.record(z.string(), z.record(z.string(), z.any())).optional(),
   })
   .refine((data) => !!(data.dxt_version || data.manifest_version), {
     message:

test/schemas.test.ts

@@ -136,4 +136,75 @@ describe("McpbManifestSchema", () => {
       expect(result.success).toBe(true);
     });
   });
+
+  describe("_meta", () => {
+    const base = {
+      manifest_version: "0.2",
+      name: "client-ext-test",
+      version: "1.0.0",
+      description: "Test manifest",
+      author: { name: "Author" },
+      server: {
+        type: "node" as const,
+        entry_point: "server/index.js",
+        mcp_config: { command: "node", args: ["server/index.js"] },
+      },
+    };
+
+    it("accepts valid _meta object with nested dictionaries", () => {
+      const manifest = {
+        ...base,
+        _meta: {
+          "com.microsoft.windows": { package_family_name: "Pkg_123", channel: "stable" },
+          "com.apple.darwin": { bundle_id: "com.example.app", notarized: true },
+        },
+      };
+      const result = McpbManifestSchema.safeParse(manifest);
+      expect(result.success).toBe(true);
+    });
+
+    it("rejects primitive value in _meta entry", () => {
+      const manifest = {
+        ...base,
+        _meta: {
+          "com.microsoft.windows": "raw-string" as unknown as Record<string, unknown>,
+        },
+      };
+      const result = McpbManifestSchema.safeParse(manifest);
+      expect(result.success).toBe(false);
+      if (!result.success) {
+        const messages = result.error.issues.map((i) => i.message).join("\n");
+        expect(messages).toMatch(/Expected object/);
+      }
+    });
+
+    it("rejects array value in _meta entry", () => {
+      const manifest = {
+        ...base,
+        _meta: {
+          "com.apple.darwin": [] as unknown as Record<string, unknown>,
+        },
+      };
+      const result = McpbManifestSchema.safeParse(manifest);
+      expect(result.success).toBe(false);
+    });
+
+    it("rejects null value in _meta entry", () => {
+      const manifest = {
+        ...base,
+        _meta: {
+          custom: null as unknown as Record<string, unknown>,
+        },
+      };
+      const result = McpbManifestSchema.safeParse(manifest);
+      expect(result.success).toBe(false);
+    });
+
+    it("allows empty object for _meta", () => {
+      const manifest = { ...base, _meta: {} };
+      const result = McpbManifestSchema.safeParse(manifest);
+      expect(result.success).toBe(true);
+    });
+  });
+
 });