Refactor package registry documentation and schema: remove on-device specific fields and update changelog; those fields now go into _meta under com.microsoft.windows (or other vendor-specific namespace)

Author: asklar

docs/guides/contributing/add-package-registry.md

@@ -38,7 +38,7 @@ These steps may evolve as additional validations or details are discovered and m
      - Add your package registry base url to the `registryBaseUrl` example array.
      - Add the single-shot CLI command name to the `runtimeHint` example value array.
    - Update the [`openapi.yaml`](../../reference/api/openapi.yaml)
-   - Add your package registry name to the `registryType` enum value array (not needed for `on_device`, which is already defined).
+   - Add your package registry name to the `registryType` enum value array.
      - Add your package registry base url to the `registryBaseUrl` enum value array.
      - Add the single-shot CLI command name to the `runtimeHint` example value array.
    - Add a sample, minimal `server.json` to the [`server.json` examples](../../reference/server-json/generic-server-json.md).

docs/reference/api/openapi.yaml

@@ -337,13 +337,6 @@ components:
           description: A mapping of environment variables to be set when running the package.
           items:
             $ref: '#/components/schemas/KeyValueInput'
-        manifest:
-          type: object
-          description: Optional embedded MCPB manifest describing an on-device server. Only used when registryType is 'on_device'.
-          additionalProperties: true
-        __dirname:
-          type: string
-          description: Optional local directory path containing the on-device server implementation (analogous to Node.js __dirname). Only used when registryType is 'on_device'.
 
     Input:
       type: object

docs/reference/server-json/CHANGELOG.md

@@ -5,10 +5,7 @@ Changes to the server.json schema and format.
 ## Unreleased
 
 ### Added
-- Support for `on_device` `registryType` for pre-installed/system-managed MCP servers.
-- New optional `manifest` field on package objects (used with `on_device`) to embed an MCPB-style manifest.
-- New optional `__dirname` field on package objects to specify the local directory containing on-device server assets.
-
+- Support for `on_device` `registryType` for pre-installed/system-managed MCP servers. For servers marked as such, registries provide MCPB manifests and `__dirname` in `server._meta`.
 
 ## 2025-09-29
 

docs/reference/server-json/generic-server-json.md

@@ -694,7 +694,11 @@ Some platforms (e.g., an operating system distribution) may provide a catalog of
       "identifier": "com.example.troubleshooting",
       "version": "1.0.0",
       "runtimeHint": "odr.exe",
-      "transport": { "type": "stdio" },
+      "transport": { "type": "stdio" }
+    }
+  ],
+  "_meta": {
+    "com.microsoft.windows": {
       "manifest": {
         "manifest_version": "0.2",
         "name": "troubleshooting-mcp-server",
@@ -703,7 +707,7 @@ Some platforms (e.g., an operating system distribution) may provide a catalog of
         "author": { "name": "ExampleOS" },
         "server": {
           "type": "binary",
-          "entry_point": "C:\\Windows\\System32\\odr.exe",
+          "entry_point": "odr.exe",
           "mcp_config": {
             "command": "odr.exe",
             "args": ["mcp", "--proxy", "troubleshooting-mcp-server"]
@@ -712,14 +716,14 @@ Some platforms (e.g., an operating system distribution) may provide a catalog of
       },
       "__dirname": "C:\\Windows\\System32\\mcp\\troubleshooting"
     }
-  ]
+  }
 }
 ```
 
 Notes:
 
 - `registryBaseUrl` is omitted because the package is not fetched remotely.
-- `manifest` embeds the MCPB-style metadata so clients have consistent information without a download.
+- `manifest` embeds the MCPB manifest so clients have consistent information without a download.
 - `__dirname` gives clients a stable local path if they need to resolve relative resources (optional).
 - Validation for `on_device` packages does not perform remote ownership checks; responsibility shifts to the platform distribution.
 

docs/reference/server-json/server.schema.json

@@ -192,10 +192,6 @@
     },
     "Package": {
       "properties": {
-        "__dirname": {
-          "description": "Optional local directory path containing the on-device server implementation (analogous to Node.js __dirname). Only used when registryType is 'on_device'.",
-          "type": "string"
-        },
         "environmentVariables": {
           "description": "A mapping of environment variables to be set when running the package.",
           "items": {
@@ -217,11 +213,6 @@
           ],
           "type": "string"
         },
-        "manifest": {
-          "additionalProperties": true,
-          "description": "Optional embedded MCPB manifest describing an on-device server. Only used when registryType is 'on_device'.",
-          "type": "object"
-        },
         "packageArguments": {
           "description": "A list of arguments to be passed to the package's binary.",
           "items": {

pkg/model/types.go

@@ -31,10 +31,6 @@ type Package struct {
 	RuntimeArguments     []Argument      `json:"runtimeArguments,omitempty"`
 	PackageArguments     []Argument      `json:"packageArguments,omitempty"`
 	EnvironmentVariables []KeyValueInput `json:"environmentVariables,omitempty"`
-	// Manifest is an optional embedded MCPB manifest describing an on-device server. Only used when registryType == on_device.
-	Manifest map[string]any `json:"manifest,omitempty"`
-	// Dirname is the directory on the local filesystem containing the on-device server (mirrors Node.js __dirname semantics for discovery). Only used when registryType == on_device.
-	Dirname string `json:"__dirname,omitempty"`
 }
 
 // Repository represents a source code repository as defined in the spec