Wrong server schema breaks clients

[hstaudacher]

Describe the bug
Servers from https://registry.modelcontextprotocol.io/ use the wrong schema. This causes clients like VSCode to break.

To Reproduce
Steps to reproduce the behavior:

1. Set the VSCode config key "chat.mcp.gallery.serviceUrl": "https://registry.modelcontextprotocol.io/"
2. Reload the window
3. See in the Output window a serialization issues
4. Search @mcp in the extension tab. You only have a limited amount of servers

Expected behavior
The server link the correct schema and not the schema from the time of publish.

Logs

Additional context
One example server is this one:

{
  "server": {
    "$schema": "https://static.modelcontextprotocol.io/schemas/2025-09-16/server.schema.json",
    "name": "ai.smithery/BowenXU0126-aistudio_hw3",
    "description": "Send personalized greetings with optional pirate flair. Compose friendly salutations for any name…",
    "repository": {
      "url": "https://github.com/BowenXU0126/aistudio_hw3",
      "source": "github"
    },
    "version": "1.16.0",
    "remotes": [
      {
        "type": "streamable-http",
        "url": "https://server.smithery.ai/@BowenXU0126/aistudio_hw3/mcp",
        "headers": [
          {
            "description": "Bearer token for Smithery authentication",
            "value": "Bearer {smithery_api_key}",
            "name": "Authorization"
          }
        ]
      }
    ]
  },

It uses the 2025-09-16 which does not work and causes a serialization issue if schema validation is enabled. Setting the schema manually to 2025-09-29 resolves the issue.

[b-gutman]

Confirming this is still happening as of 2026-06-03, and it's systemic rather than a few stale entries. We sync the full /v0/servers feed daily for Pipeworx, and in a fresh 100-entry sample the live API serves four distinct server.$schema versions simultaneously:

$schema	count
2025-12-11 (current)	93
2025-09-29	5
2025-10-17	1
2025-07-09	1

So ~7% of entries reference a pre-current schema and will fail strict validation against the current one — matching the VSCode serialization breakage above. Entries appear pinned to their publish-time schema with no migration/normalization on read.

Two options that would fix it for consumers without forcing republish: (a) normalize $schema to the current version on the read path, or (b) document a stable "latest" alias so clients can validate against a single known schema. Happy to share the sampling script if useful.