How do I add an extension plugin?

[dominikwilkowski]

I'd love to add a plugin that shows things inside the editor per line.

Looking at the extensions repo it mentions so far the only things supported are syntax, language and themes.

Looking at the roadmap under Adoption it mentions "Plugins" under "Extensibility" which I assume might be the term we use for this?

Is that a thing yet? If so are there any docs yet? Sorry if I missed it.

[SomeoneToIgnore]

zed/crates/extension_api/src/extension_api.rs

Lines 59 to 118 in 1a0fd73

	pub trait Extension: Send + Sync {
	/// Returns a new instance of the extension.
	fn new() -> Self
	where
	Self: Sized;
	/// Returns the command used to start the language server for the specified
	/// language.
	fn language_server_command(
	&mut self,
	language_server_id: &LanguageServerId,
	worktree: &Worktree,
	) -> Result<Command>;
	/// Returns the initialization options to pass to the specified language server.
	fn language_server_initialization_options(
	&mut self,
	_language_server_id: &LanguageServerId,
	_worktree: &Worktree,
	) -> Result<Option<serde_json::Value>> {
	Ok(None)
	}
	/// Returns the workspace configuration options to pass to the language server.
	fn language_server_workspace_configuration(
	&mut self,
	_language_server_id: &LanguageServerId,
	_worktree: &Worktree,
	) -> Result<Option<serde_json::Value>> {
	Ok(None)
	}
	/// Returns the label for the given completion.
	fn label_for_completion(
	&self,
	_language_server_id: &LanguageServerId,
	_completion: Completion,
	) -> Option<CodeLabel> {
	None
	}
	/// Returns the label for the given symbol.
	fn label_for_symbol(
	&self,
	_language_server_id: &LanguageServerId,
	_symbol: Symbol,
	) -> Option<CodeLabel> {
	None
	}
	/// Runs the given slash command.
	fn run_slash_command(
	&self,
	_command: SlashCommand,
	_argument: Option<String>,
	_worktree: &Worktree,
	) -> Result<Option<String>, String> {
	Ok(None)
	}
	}

Currently, this is all any extension is able to do programmatically, so there's no editor-related API yet and extensions cannot directly influence what is displayed on the screen.

So seems like it's impossible now.