Seeking Help: Errors When Using VS Code AI Extensions in Theia-IDE

[NO-MAP]

I am trying to install and use some VS Code AI coding extensions in Theia-IDE. The installations are successful and the extensions can be launched, but I encountered the following errors during runtime:

1. After installing Alibaba-Cloud.tongyi-lingma:
   • Login works normally, and both the chat and agent features function properly.
   • However, when triggering code completion, the following error occurs:

2025-09-08T05:34:54.537Z plugin-host INFO Cosy InlineCompletion error.  Error: Invalid arguments
    at new c (D:\software\theia-ide\TheiaIDE\resources\app\lib\backend\366.js:1:9535)
    at new c (D:\software\theia-ide\TheiaIDE\resources\app\lib\backend\366.js:1:143164)
    at t.CosyInlineCompletionProvider.provideInlineCompletionItems (C:\Users\z25347\.theia-ide\deployedPlugins\alibaba-cloud.tongyi-lingma-2.5.17\extension\dist\extension.js:2:1009570)
    at async t.InlineCompletionAdapter.provideInlineCompletions (D:\software\theia-ide\TheiaIDE\resources\app\lib\backend\339.js:1:407919)
    at async c.handleRequest (D:\software\theia-ide\TheiaIDE\resources\app\lib\backend\69.js:2:17236) Invalid arguments

2. After installing MarsCode.marscode-extension (Trae for VS Code extension):
   • The login fails directly with the following error:

logger-protocol.ts:118 2025-09-08T05:37:41.332Z plugin-host ERROR Promise rejection not handled in one second: Error: Command with id 'workbench.view.extension.trae' is not registered. , reason: Error: Command with id 'workbench.view.extension.trae' is not registered.

Does anyone know what might be causing these issues? Would modifying the code of Theia-IDE help resolve the problems?
By the way, some other AI extensions (like tencent-cloud.coding-copilot) work completely fine, so this doesn’t seem to be a simple VS Code API compatibility issue.

[msujew]

Hey @NO-MAP,

Do you mind creating an issue for the first one? It looks like some VSCode extension incompatibility on our end.

The second error is already fixed on master with #16239 and will be published at the end of the month.

[msujew]

Ah, yes. It seems like VS Code registers one command for the actual view (with the .open suffix) and one for the view container. See here. We seem to be missing the latter.

[NO-MAP]

I did some searching in the VS Code repository and found the following code:
registerCustomViewContainers

private registerCustomViewContainers(containers: IUserFriendlyViewsContainerDescriptor[], extension: IExtensionDescription, order: number, existingViewContainers: ViewContainer[], location: ViewContainerLocation): number {
    containers.forEach(descriptor => {
        const themeIcon = ThemeIcon.fromString(descriptor.icon);

        const icon = themeIcon || resources.joinPath(extension.extensionLocation, descriptor.icon);
        const id = `workbench.view.extension.${descriptor.id}`;
        const title = descriptor.title || id;
        const viewContainer = this.registerCustomViewContainer(id, title, icon, order++, extension.identifier, location);

        // Move those views that belongs to this container
        if (existingViewContainers.length) {
            const viewsToMove: IViewDescriptor[] = [];
            for (const existingViewContainer of existingViewContainers) {
                if (viewContainer !== existingViewContainer) {
                    viewsToMove.push(...this.viewsRegistry.getViews(existingViewContainer).filter(view => (view as ICustomViewDescriptor).originalContainerId === descriptor.id));
                }
            }
            if (viewsToMove.length) {
                this.viewsRegistry.moveViews(viewsToMove, viewContainer);
            }
        }
    });
    return order;
}

It seems like this is registering workbench.view.extension.id. Are you familiar with this part of the logic?

[NO-MAP]

Ah, yes. It seems like VS Code registers one command for the actual view (with the .open suffix) and one for the view container. See here. We seem to be missing the latter.

Awesome! In which version is this issue expected to be resolved?

[msujew]

None yet, feel free to provide a PR :)

[NO-MAP]

None yet, feel free to provide a PR :)

Sorry, I tried to clarify the differences in the command registration logic during plugin startup between Theia and VSCode, hoping to add the registration of the workbench.view.extension.${viewContainer.id} command. A day has passed, and I still haven't made much progress. I finally decided to submit an issue for tracking.
[vscode] Theia does not register the workbench.view.extension.${viewContainer.id} command, causing some plugins that rely on this command to malfunction #16271