Make mcpb package version optional and fix schema validation (#686)

<!-- Provide a brief summary of your changes -->

## Motivation and Context
<!-- Why is this change needed? What problem does it solve? -->
The following PR:
* Makes mcpb package version property optional
* Bumps the schema and reflects that in the code
* Makes sure the publisher tests are being covered by doing `make check`

## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->

## Breaking Changes
<!-- Will users need to update their code or configurations? -->

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

---------

Signed-off-by: Radoslav Dimitrov <[email protected]>

Author: rdimitrov

Makefile

@@ -32,7 +32,7 @@ test-unit: ## Run unit tests with coverage (requires PostgreSQL)
 	@echo "Waiting for PostgreSQL to be ready..."
 	@sleep 3
 	@echo "Running unit tests..."
-	go test -v -race -coverprofile=coverage.out -covermode=atomic ./internal/...
+	go test -v -race -coverprofile=coverage.out -covermode=atomic ./internal/... ./cmd/...
 	go tool cover -html=coverage.out -o coverage.html
 	@echo "Coverage report generated: coverage.html"
 	@echo "Stopping PostgreSQL..."

cmd/publisher/commands/publish_test.go

@@ -44,8 +44,8 @@ func TestPublishCommand_DeprecatedSchema(t *testing.T) {
 			errorSubstr: "deprecated schema detected",
 		},
 		{
-			name:        "current 2025-09-29 schema should pass validation",
-			schema:      "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+			name:        "current 2025-10-17 schema should pass validation",
+			schema:      "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
 			expectError: false,
 		},
 		{

data/seed.json

@@ -1,6 +1,6 @@
 [
   {
-    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
     "name": "io.github.domdomegg/airtable-mcp-server",
     "description": "Read and write access to Airtable database schemas, tables, and records.",
     "repository": {
@@ -62,7 +62,7 @@
     ]
   },
   {
-    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
     "name": "io.github.domdomegg/airtable-mcp-server",
     "description": "Read and write access to Airtable database schemas, tables, and records.",
     "repository": {
@@ -115,7 +115,7 @@
     ]
   },
   {
-    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
     "name": "io.github.domdomegg/time-mcp-nuget",
     "description": "Get the current UTC time in RFC 3339 format.",
     "repository": {
@@ -136,7 +136,7 @@
     ]
   },
   {
-    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
     "name": "io.github.domdomegg/time-mcp-pypi",
     "description": "Get the current UTC time in RFC 3339 format.",
     "repository": {

docs/guides/consuming/use-rest-api.md

@@ -67,7 +67,7 @@ You can also add custom metadata to servers using the `_meta` field. For example
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.yourname/weather-server",
   "description": "MCP server for weather data access",
   "status": "active",

docs/guides/publishing/publish-server.md

@@ -93,7 +93,7 @@ This creates a `server.json` with auto-detected values. You'll see something lik
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.yourname/weather-data-mcp",
   "title": "Weather Data",
   "description": "Access real-time weather data and forecasts",
@@ -153,7 +153,7 @@ Add an `mcpName` field to your `package.json`:
 ### Example server.json
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.username/slack-integration-mcp",
   "title": "Slack Integration",
   "description": "Send messages and manage Slack workspaces",
@@ -192,7 +192,7 @@ Add it to your README.md file (which becomes the package description on PyPI). T
 ### Example server.json
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.username/database-query-mcp",
   "title": "Database Query",
   "description": "Execute SQL queries and manage database connections",
@@ -231,7 +231,7 @@ Add a README file to your NuGet package that includes the server name. This can
 ### Example server.json
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.username/azure-devops-mcp",
   "title": "Azure DevOps",
   "description": "Manage Azure DevOps work items and pipelines",
@@ -274,17 +274,15 @@ LABEL io.modelcontextprotocol.server.name="io.github.username/server-name"
 ### Example server.json (Docker Hub)
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.username/kubernetes-manager-mcp",
   "title": "Kubernetes Manager",
   "description": "Deploy and manage Kubernetes resources",
   "version": "1.0.0",
   "packages": [
     {
       "registryType": "oci",
-      "registryBaseUrl": "https://docker.io",
-      "identifier": "yourusername/kubernetes-manager-mcp",
-      "version": "1.0.0",
+      "identifier": "docker.io/yourusername/kubernetes-manager-mcp:1.0.0",
       "transport": {
         "type": "stdio"
       }
@@ -296,17 +294,15 @@ LABEL io.modelcontextprotocol.server.name="io.github.username/server-name"
 ### Example server.json (GitHub Container Registry)
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.username/git-operations-mcp",
   "title": "Git Operations",
   "description": "Advanced Git repository management and operations",
   "version": "1.0.0",
   "packages": [
     {
       "registryType": "oci",
-      "registryBaseUrl": "https://ghcr.io",
-      "identifier": "username/git-operations-mcp",
-      "version": "1.0.0",
+      "identifier": "ghcr.io/username/git-operations-mcp:1.0.0",
       "transport": {
         "type": "stdio"
       }
@@ -315,9 +311,9 @@ LABEL io.modelcontextprotocol.server.name="io.github.username/server-name"
 }
 ```
 
-The identifier is `namespace/repository`, and version is the tag and optionally digest.
+The identifier format is `registry/namespace/repository:tag` (e.g., `docker.io/user/app:1.0.0` or `ghcr.io/user/app:1.0.0`). The version can also be specified as a digest.
 
-The official MCP registry currently supports Docker Hub (`https://docker.io`) and GitHub Container Registry (`https://ghcr.io`).
+The official MCP registry currently supports Docker Hub (`docker.io`) and GitHub Container Registry (`ghcr.io`).
 
 </details>
 
@@ -339,7 +335,7 @@ openssl dgst -sha256 server.mcpb
 ### Example server.json
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.username/image-processor-mcp",
   "title": "Image Processor",
   "description": "Process and transform images with various filters",
@@ -348,7 +344,6 @@ openssl dgst -sha256 server.mcpb
     {
       "registryType": "mcpb",
       "identifier": "https://github.com/username/image-processor-mcp/releases/download/v1.0.0/image-processor.mcpb",
-      "version": "1.0.0",
       "fileSha256": "fe333e598595000ae021bd27117db32ec69af6987f507ba7a63c90638ff633ce",
       "transport": {
         "type": "stdio"
@@ -385,7 +380,7 @@ Add the `remotes` field to your `server.json` (can coexist with `packages`):
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "com.yourcompany/acme-analytics",
   "title": "ACME Analytics",
   "description": "Real-time business intelligence and reporting platform",

docs/reference/api/openapi.yaml

@@ -1,9 +1,9 @@
 openapi: 3.1.0
 jsonSchemaDialect: "https://json-schema.org/draft/2020-12/schema"
-$id: https://modelcontextprotocol.io/schemas/draft/2025-10-11/server-registry-openapi
+$id: https://modelcontextprotocol.io/schemas/draft/2025-10-17/server-registry-openapi
 info:
   title: MCP Server Registry API
-  version: "2025-10-11"
+  version: "2025-10-17"
   summary: API for discovering and accessing MCP server metadata
   description: |
     Specification for a theoretical REST API that serves up metadata about MCP servers.
@@ -616,7 +616,7 @@ components:
           type: string
           format: uri
           description: JSON Schema URI for this server.json format
-          example: "https://static.modelcontextprotocol.io/schemas/2025-10-11/server.schema.json"
+          example: "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json"
         packages:
           type: array
           items:

docs/reference/server-json/CHANGELOG.md

@@ -2,6 +2,60 @@
 
 Changes to the server.json schema and format.
 
+## 2025-10-17
+
+### Changed
+
+The `version` field is now **optional** for MCPB packages, providing flexibility for publishers.
+
+**Key Changes:**
+
+- **MCPB packages can now include an optional `version` field** - Previously rejected by validation, MCPB packages can now optionally specify a version field for clarity and metadata purposes.
+- **Both formats are valid**:
+  - MCPB packages **with** version field: Provides explicit version metadata
+  - MCPB packages **without** version field: Version information is embedded in the download URL (as before)
+
+**Migration:**
+
+Publishers using MCPB packages can optionally add a `version` field to their package configuration. This is particularly useful when:
+- The version information is not clearly visible in the download URL
+- You want to provide explicit version metadata for tooling and clients
+- You need consistent version tracking across different package types
+
+Existing MCPB packages without the version field continue to work without any changes.
+
+**Example - MCPB Package with optional version:**
+```json
+{
+  "packages": [{
+    "registryType": "mcpb",
+    "identifier": "https://github.com/example/releases/download/v1.0.0/package.mcpb",
+    "version": "1.0.0",
+    "fileSha256": "fe333e598595000ae021bd27117db32ec69af6987f507ba7a63c90638ff633ce",
+    "transport": {
+      "type": "stdio"
+    }
+  }]
+}
+```
+
+**Example - MCPB Package without version (still valid):**
+```json
+{
+  "packages": [{
+    "registryType": "mcpb",
+    "identifier": "https://github.com/example/releases/download/v1.0.0/package.mcpb",
+    "fileSha256": "fe333e598595000ae021bd27117db32ec69af6987f507ba7a63c90638ff633ce",
+    "transport": {
+      "type": "stdio"
+    }
+  }]
+}
+```
+
+### Schema Version
+- Schema version: `2025-10-11` → `2025-10-17`
+
 ## 2025-10-11
 
 ### Changed

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

@@ -22,7 +22,7 @@ The official registry has some more restrictions on top of this. See the [offici
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.modelcontextprotocol.anonymous/brave-search",
   "description": "MCP server for Brave Search API integration",
   "title": "Brave Search",
@@ -69,7 +69,7 @@ For MCP servers located within a subdirectory of a larger repository (monorepo s
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.modelcontextprotocol/everything",
   "description": "MCP server that exercises all the features of the MCP protocol",
   "title": "Everything",
@@ -108,7 +108,7 @@ Suppose your MCP server application requires a `mcp start` CLI arguments to star
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.joelverhagen/knapcode-samplemcpserver",
   "description": "Sample NuGet MCP server for a random number and random weather",
   "version": "0.4.0-beta",
@@ -152,7 +152,7 @@ This will essentially instruct the MCP client to execute `dnx Knapcode.SampleMcp
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.modelcontextprotocol/filesystem",
   "description": "Node.js server implementing Model Context Protocol (MCP) for filesystem operations.",
   "title": "Filesystem",
@@ -252,7 +252,7 @@ This will essentially instruct the MCP client to execute `dnx Knapcode.SampleMcp
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.modelcontextprotocol.anonymous/mcp-fs",
   "description": "Cloud-hosted MCP filesystem server",
   "repository": {
@@ -286,7 +286,7 @@ This will essentially instruct the MCP client to execute `dnx Knapcode.SampleMcp
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.example/weather-mcp",
   "description": "Python MCP server for weather data access",
   "title": "Weather",
@@ -342,7 +342,7 @@ The `dnx` tool ships with the .NET 10 SDK, starting with Preview 6.
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.joelverhagen/knapcode-samplemcpserver",
   "description": "Sample NuGet MCP server for a random number and random weather",
   "repository": {
@@ -391,7 +391,7 @@ The `dnx` tool ships with the .NET 10 SDK, starting with Preview 6.
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.github.example/database-manager",
   "description": "MCP server for database operations with support for multiple database types",
   "repository": {
@@ -500,7 +500,7 @@ The `dnx` tool ships with the .NET 10 SDK, starting with Preview 6.
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.modelcontextprotocol.anonymous/hybrid-mcp",
   "description": "MCP server available as both local package and remote service",
   "title": "Hybrid",
@@ -586,7 +586,7 @@ The `dnx` tool ships with the .NET 10 SDK, starting with Preview 6.
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.modelcontextprotocol/text-editor",
   "description": "MCP Bundle server for advanced text editing capabilities",
   "title": "Text Editor",
@@ -629,7 +629,7 @@ Some CLI tools bundle an MCP server, without a standalone MCP package or a publi
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.snyk/cli-mcp",
   "description": "MCP server provided by the Snyk CLI",
   "title": "Snyk",
@@ -664,7 +664,7 @@ For MCP servers that follow a custom installation path or are embedded in applic
 
 ```json
 {
-  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-29/server.schema.json",
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "name": "io.modelcontextprotocol.anonymous/embedded-mcp",
   "description": "MCP server embedded in a Desktop app",
   "websiteUrl": "https://anonymous.modelcontextprotocol.io/embedded-mcp-guide",

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

@@ -1,6 +1,6 @@
 {
   "$comment": "This file is auto-generated from docs/reference/api/openapi.yaml. Do not edit manually. Run 'make generate-schema' to update.",
-  "$id": "https://static.modelcontextprotocol.io/schemas/2025-10-11/server.schema.json",
+  "$id": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
   "$ref": "#/definitions/ServerDetail",
   "$schema": "http://json-schema.org/draft-07/schema#",
   "definitions": {
@@ -373,7 +373,7 @@
       "properties": {
         "$schema": {
           "description": "JSON Schema URI for this server.json format",
-          "example": "https://static.modelcontextprotocol.io/schemas/2025-10-11/server.schema.json",
+          "example": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
           "format": "uri",
           "type": "string"
         },