koto-ls
With the release of koto-ls, Koto now has an LSP server, greatly improving Koto's editing experience.
koto-ls provides several useful IDE features like renaming symbols and jump-to-definition. With the Rust toolchain available on your system, koto-ls can be installed easily via cargo install koto-ls.
If you use the Helix editor, then koto-ls will start working automatically when opening a .koto file. For help on getting set up with other editors, and more information in general, take a look at the koto-ls readme.