feat: replace manifest_version with $schema field

- Replace manifest_version with $schema field pointing to official schema URL
- Support backward compatibility with legacy dxt_version field
- Update all examples and tests to use new $schema field
- Mark dxt_version as deprecated but still functional
- Require either $schema or dxt_version (at least one must be present)

src/cli/init.ts

@@ -773,7 +773,7 @@ export function buildManifest(
   const { keywords, license, repository } = optionalFields;
 
   return {
-    manifest_version: "0.1",
+    $schema: "https://static.modelcontextprotocol.io/schemas/2025-08-26/mcpb.manifest.schema.json",
     name,
     ...(displayName && displayName !== name
       ? { display_name: displayName }

src/schemas-loose.ts

@@ -79,8 +79,7 @@ export const McpbUserConfigValuesSchema = z.record(
 export const McpbManifestSchema = z
   .object({
     $schema: z.string().optional(),
-    dxt_version: z.string().optional().describe("@deprecated Use manifest_version instead"),
-    manifest_version: z.string().optional(),
+    dxt_version: z.string().optional().describe("@deprecated - Use $schema instead"),
   name: z.string(),
   display_name: z.string().optional(),
   version: z.string(),
@@ -106,9 +105,9 @@ export const McpbManifestSchema = z
     .optional(),
   })
   .refine(
-    (data) => !!(data.dxt_version || data.manifest_version),
+    (data) => !!(data.$schema || data.dxt_version),
     {
-      message: "Either 'dxt_version' (deprecated) or 'manifest_version' must be provided",
+      message: "Either '$schema' or 'dxt_version' (deprecated) must be provided",
     }
   );
 

src/schemas.ts

@@ -79,8 +79,7 @@ export const McpbUserConfigValuesSchema = z.record(
 export const McpbManifestSchema = z
   .strictObject({
     $schema: z.string().optional(),
-    dxt_version: z.string().optional().describe("@deprecated Use manifest_version instead"),
-    manifest_version: z.string().optional(),
+    dxt_version: z.string().optional().describe("@deprecated - Use $schema instead"),
     name: z.string(),
     display_name: z.string().optional(),
     version: z.string(),
@@ -106,9 +105,9 @@ export const McpbManifestSchema = z
       .optional(),
   })
   .refine(
-    (data) => !!(data.dxt_version || data.manifest_version),
+    (data) => !!(data.$schema || data.dxt_version),
     {
-      message: "Either 'dxt_version' (deprecated) or 'manifest_version' must be provided",
+      message: "Either '$schema' or 'dxt_version' (deprecated) must be provided",
     }
   );