VSCode "Failed to fetch" local vanilla registry

[dhrapson]

Describe the bug
When I deploy a local registry and attempt to connect to it from VS Code, the message from VSC comes back as:

2026-01-19 10:09:18.047 [error] [Network] #331: http://localhost:8080/v0.1/servers?limit=50&version=latest - error GET Failed to fetch
2026-01-19 10:09:18.051 [error] [Window] Failed to fetch: TypeError: Failed to fetch
    at DSn (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:3877:37272)
    at vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:3877:38498
    at NDt.c (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:517:10759)
    at NDt.request (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:3877:38490)
    at Att.n (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:1370:16547)
    at Att.m (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:1370:16052)
    at Att.query (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:1370:13179)
    at async fmt.queryGallery (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:2597:10208)
    at async az.kc (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:2597:957)
    at async az.show (vscode-file://vscode-app/Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:2595:9720)

It is unclear to me whether this is a broken MCP Registry, an incompatibility with VS Code version, or something else entirely.

To Reproduce
Steps to reproduce the behavior:

1. make dev-compose
2. configure GitHub Enterprise to allow Registry Only from http://localhost:8080
3. in VSCode -> Extensions filter for @mcp. Observe Failed to fetch popup
4. Go to VSCode -> output -> Window and observe the full stack trace

Expected behavior
Show a list of MCP servers in VSCode -> Extensions filter for @mcp

Logs
No logs from the MCP registry

Additional context
github.com/modelcontextprotocol/registry.git version: fc88cf0
VSCode version details

Version: 1.108.0 (Universal)
Commit: 94e8ae2b28cb5cc932b86e1070569c4463565c37
Date: 2026-01-08T13:53:10.781Z
Electron: 39.2.7
ElectronBuildId: 12953945
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.5.0