What does "$schema" do?

[a-biad]

Hello. What is the $schema field used for in the config file?
"$schema" = 'https://starship.rs/config-schema.json'

Does it trigger a network request? If so is it possible to disable it?

[davidkna]

It defines the location where you're editor or lsp responsible for toml can download a specification of the configuration file format use by starship (which options are available etc.).

You will need to disable such downloads in your editor/lsp (if they support this). Even if you delete the line, there may still be a network requests, because the schema is listed at https://www.schemastore.org and you're editor/lsp may automatically fetch it.