The VS Code API does not have a clear way of allowing the use of "ghost text". Nevertheless, the GitHub Copilot Chat extension seems to be able to use it. It may be worth examining how they do it, in order to determine if we can do the same for preview effects.
I believe I have found the approximate location where ghost text is implemented (might also be a different file nearby):
https://github.com/microsoft/vscode-copilot-chat/blob/main/src/extension/completions-core/vscode-node/lib/src/ghostText/ghostText.ts
The VS Code API does not have a clear way of allowing the use of "ghost text". Nevertheless, the GitHub Copilot Chat extension seems to be able to use it. It may be worth examining how they do it, in order to determine if we can do the same for preview effects.
I believe I have found the approximate location where ghost text is implemented (might also be a different file nearby):
https://github.com/microsoft/vscode-copilot-chat/blob/main/src/extension/completions-core/vscode-node/lib/src/ghostText/ghostText.ts