In this project there's an LSP server for Refact. It almost works well, but it adds text to a popup in Sublime, doesn't show the gray text.

The mini_auto_complete option in Sublime replaces popup with a single line gray text, but it's not the right thing either.

The right thing would be multiline gray text, and it so happens the upcoming LSP standard version 3.18 has the official support for it, called InlineCompletion.

This issue/bounty is for implementing it correctly in Sublime.

Some tricky parts:

• Showing gray text and popup might conflict, the popup has its strengths too. So the decision about which suggestion to show might be tricky, sure it's shouldn't show both at the same time.

• Grey text should not increase visible line counters, for example a code suggestion at line 100 that has 5 lines shouldn't make the next line 106 before it's accepted.

• They should accept the changes to implement this at Sublime and Sublime LSP plugin.

A discussion at Sublime forum, they also have Discord.