diff --git a/src/lspc.rs b/src/lspc.rs
index 17b4e0e..79587f2 100644
--- a/src/lspc.rs
+++ b/src/lspc.rs
@@ -163,6 +163,8 @@ pub trait Editor: 'static {
     fn events(&self) -> Receiver<Event>;
     fn capabilities(&self) -> lsp_types::ClientCapabilities;
     fn say_hello(&self) -> Result<(), EditorError>;
+
+    fn init(&mut self) -> Result<(), EditorError>;
     fn message(&mut self, msg: &str) -> Result<(), EditorError>;
     fn show_hover(
         &mut self,
@@ -176,6 +178,11 @@ pub trait Editor: 'static {
     ) -> Result<(), EditorError>;
     fn show_message(&mut self, show_message_params: &ShowMessageParams) -> Result<(), EditorError>;
     fn show_references(&mut self, locations: &Vec<Location>) -> Result<(), EditorError>;
+    fn show_diagnostics(
+        &mut self,
+        text_document: &TextDocumentIdentifier,
+        diagnostics: &[lsp_types::Diagnostic],
+    ) -> Result<(), EditorError>;
     fn goto(&mut self, location: &Location) -> Result<(), EditorError>;
     fn apply_edits(&self, lines: &Vec<String>, edits: &Vec<TextEdit>) -> Result<(), EditorError>;
     fn track_all_buffers(&self) -> Result<(), EditorError>;
@@ -645,6 +652,23 @@ impl<E: Editor> Lspc<E> {
                     }
                     Err(noti) => noti,
                 };
+                noti = match noti.cast::<noti::PublishDiagnostics>() {
+                    Ok(params) => {
+                        let (_handler, _tracking_file, editor) =
+                            self.handler_for_file(&params.uri).ok_or_else(|| {
+                                log::info!(
+                                    "Received changed event for nontracking file: {:?}",
+                                    params.uri
+                                );
+                                MainLoopError::IgnoredMessage
+                            })?;
+                        let text_document = TextDocumentIdentifier::new(params.uri);
+                        editor.show_diagnostics(&text_document, &params.diagnostics)?;
+
+                        return Ok(());
+                    }
+                    Err(noti) => noti,
+                };
 
                 log::warn!("Not supported notification: {:?}", noti);
             }
@@ -702,6 +726,11 @@ impl<E: Editor> Lspc<E> {
         let event_receiver = self.editor.events();
         let timer_tick = tick(Duration::from_millis(TIMER_TICK_MS));
 
+        if let Err(e) = self.editor.init() {
+            log::error!("Editor initialization error: {:?}", e);
+            return;
+        }
+
         loop {
             let selected = select(&event_receiver, &timer_tick, &self.lsp_handlers);
             let result = match selected {
diff --git a/src/neovim.rs b/src/neovim.rs
index 16e0c75..675ca0a 100644
--- a/src/neovim.rs
+++ b/src/neovim.rs
@@ -28,7 +28,7 @@ use rmpv::{
 use serde::{
     self,
     de::{self, SeqAccess, Visitor},
-    ser::SerializeSeq,
+    ser::{SerializeMap, SerializeSeq},
     Deserialize, Serialize,
 };
 use url::Url;
@@ -42,6 +42,7 @@ pub struct Neovim {
     next_id: AtomicU64,
     subscription_sender: Sender<(u64, Sender<NvimMessage>)>,
     thread: JoinHandle<()>,
+    buf_mapper: Arc<Mutex<BiMap<i64, Url>>>
 }
 
 pub trait ToDisplay {
@@ -443,6 +444,7 @@ impl Neovim {
             event_receiver,
             rpc_client,
             thread,
+            buf_mapper,
         }
     }
 
@@ -493,7 +495,7 @@ impl Neovim {
             .map_err(|_| EditorError::Timeout)
     }
 
-    pub fn notify(&self, method: &str, params: &[Value]) -> Result<(), EditorError> {
+    pub fn notify(&self, method: &str, params: Value) -> Result<(), EditorError> {
         let noti = NvimMessage::RpcNotification {
             method: method.into(),
             params: Value::from(params.to_owned()),
@@ -544,13 +546,14 @@ impl Neovim {
             .into();
         self.notify(
             "nvim_buf_set_virtual_text",
-            &vec![
+            vec![
                 buffer_id.into(),
                 ns_id.into(),
                 line.into(),
                 chunks,
                 Value::Map(Vec::new()),
-            ],
+            ]
+            .into(),
         )?;
 
         Ok(())
@@ -601,6 +604,13 @@ impl Editor for Neovim {
         Ok(())
     }
 
+    fn init(&mut self) -> Result<(), EditorError> {
+        // FIXME: call `nvim_set_client_info` here.
+        // FIXME: call `sign_define` here.
+
+        Ok(())
+    }
+
     fn message(&mut self, msg: &str) -> Result<(), EditorError> {
         self.command(&format!("echo '{}'", msg))?;
         Ok(())
@@ -710,6 +720,74 @@ impl Editor for Neovim {
         Ok(())
     }
 
+    fn show_diagnostics(
+        &mut self,
+        text_document: &TextDocumentIdentifier,
+        diagnostics: &[lsp::Diagnostic],
+    ) -> Result<(), EditorError> {
+        struct Placement {
+            lnum: i64,
+            priority: i64,
+        }
+
+        impl Serialize for Placement {
+            fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+            where
+                S: serde::Serializer,
+            {
+                let mut s = serializer.serialize_map(Some(2))?;
+                s.serialize_entry("lnum", &self.lnum)?;
+                s.serialize_entry("priority", &self.priority)?;
+                s.end()
+            }
+        }
+
+        let buf_id = {
+            let locked_buf_mapper = self.buf_mapper.lock().unwrap();
+            *locked_buf_mapper.get_by_right(&text_document.uri)
+                .ok_or_else(|| EditorError::Failed(format!("Buffer not found for {:?}", text_document)))?
+        };
+
+        self.notify(
+            "nvim_call_function",
+            vec![
+                Value::from("sign_unplace"),
+                vec![
+                    Value::from("lspc-diag"),
+                    Value::Map(vec![(Value::from("buffer"), Value::from(buf_id))]),
+                ].into(),
+            ].into(),
+        )?;
+
+        #[derive(Serialize)]
+        struct SignParams(i64, String, String, i64, Placement);
+        for diag in diagnostics {
+            let sign_name = match diag.severity {
+                Some(lsp::DiagnosticSeverity::Error) => "ALEErrorSign",
+                Some(lsp::DiagnosticSeverity::Warning) => "ALEWarningSign",
+                Some(lsp::DiagnosticSeverity::Information)
+                | Some(lsp::DiagnosticSeverity::Hint) => "ALEInfoSign",
+                None => "ALEErrorSign",
+            };
+            let placement = Placement {
+                lnum: diag.range.start.line as i64,
+                priority: 10,
+            };
+            let sign_params =
+                SignParams(0, "lspc-diag".into(), sign_name.into(), buf_id, placement);
+
+            let params = to_value(sign_params).map_err(|e| {
+                EditorError::Failed(format!("Failed to encode params: {}", e.description()))
+            })?;
+            self.notify(
+                "nvim_call_function",
+                vec![Value::from("sign_place"), params].into(),
+            )?;
+        }
+
+        Ok(())
+    }
+
     fn track_all_buffers(&self) -> Result<(), EditorError> {
         self.call_function("lspc#track_all_buffers", Value::Array(vec![]))?;
         Ok(())