diff --git a/crates/server/Cargo.toml b/crates/server/Cargo.toml
index e6d1b18c3e..b2a7ce5b44 100644
--- a/crates/server/Cargo.toml
+++ b/crates/server/Cargo.toml
@@ -14,5 +14,7 @@ crossbeam-channel = "0.2.4"
 threadpool = "1.7.1"
 flexi_logger = "0.9.0"
 log = "0.4.3"
+url = "1.1.0"
+
 libeditor = { path = "../libeditor" }
 libanalysis = { path = "../libanalysis" }
diff --git a/crates/server/src/dispatch.rs b/crates/server/src/dispatch.rs
index 2da0996e3b..d9681db40d 100644
--- a/crates/server/src/dispatch.rs
+++ b/crates/server/src/dispatch.rs
@@ -136,6 +136,18 @@ pub fn handle_notification<N, F>(not: &mut Option<RawNotification>, f: F) -> Res
     }
 }
 
+pub fn send_notification<N>(io: &mut Io, params: N::Params) -> Result<()>
+    where
+        N: Notification,
+        N::Params: Serialize
+{
+    io.send(RawMsg::Notification(RawNotification {
+        method: N::METHOD.to_string(),
+        params: serde_json::to_value(params)?,
+    }));
+    Ok(())
+}
+
 
 pub fn unknown_method(io: &mut Io, raw: RawRequest) -> Result<()> {
     error(io, raw.id, ErrorCode::MethodNotFound, "unknown method")
diff --git a/crates/server/src/handlers.rs b/crates/server/src/handlers.rs
index 5ee87a4ddd..1f55e8669e 100644
--- a/crates/server/src/handlers.rs
+++ b/crates/server/src/handlers.rs
@@ -1,6 +1,8 @@
-use languageserver_types::{Range, Position};
+use url::Url;
+use languageserver_types::{Range, Position, Diagnostic, DiagnosticSeverity};
 use libanalysis::World;
 use libeditor::{self, LineIndex, LineCol, TextRange, TextUnit};
+
 use {req, Result, FilePath};
 
 pub fn handle_syntax_tree(
@@ -29,6 +31,23 @@ pub fn handle_extend_selection(
     Ok(req::ExtendSelectionResult { selections })
 }
 
+pub fn publish_diagnostics(world: World, uri: Url) -> Result<req::PublishDiagnosticsParams> {
+    let path = uri.file_path()?;
+    let file = world.file_syntax(&path)?;
+    let line_index = world.file_line_index(&path)?;
+    let diagnostics = libeditor::diagnostics(&file)
+        .into_iter()
+        .map(|d| Diagnostic {
+            range: to_vs_range(&line_index, d.range),
+            severity: Some(DiagnosticSeverity::Error),
+            code: None,
+            source: Some("libsyntax2".to_string()),
+            message: d.msg,
+            related_information: None,
+        }).collect();
+    Ok(req::PublishDiagnosticsParams { uri, diagnostics })
+}
+
 
 fn to_text_range(line_index: &LineIndex, range: Range) -> TextRange {
     TextRange::from_to(
diff --git a/crates/server/src/main.rs b/crates/server/src/main.rs
index 2d8695d230..6018350e3d 100644
--- a/crates/server/src/main.rs
+++ b/crates/server/src/main.rs
@@ -11,6 +11,7 @@ extern crate crossbeam_channel;
 extern crate threadpool;
 #[macro_use]
 extern crate log;
+extern crate url;
 extern crate flexi_logger;
 extern crate libeditor;
 extern crate libanalysis;
@@ -31,7 +32,7 @@ use languageserver_types::{TextDocumentItem, VersionedTextDocumentIdentifier, Te
 
 use ::{
     io::{Io, RawMsg},
-    handlers::{handle_syntax_tree, handle_extend_selection},
+    handlers::{handle_syntax_tree, handle_extend_selection, publish_diagnostics},
 };
 
 pub type Result<T> = ::std::result::Result<T, ::failure::Error>;
@@ -209,6 +210,21 @@ fn main_loop(
                 dispatch::handle_notification::<req::DidOpenTextDocument, _>(&mut not, |params| {
                     let path = params.text_document.file_path()?;
                     world.change_overlay(path, Some(params.text_document.text));
+                    let world = world.snapshot();
+                    let sender = sender.clone();
+                    let uri = params.text_document.uri;
+                    pool.execute(move || {
+                        match publish_diagnostics(world, uri) {
+                            Err(e) => {
+                                error!("failed to compute diagnostics: {:?}", e)
+                            }
+                            Ok(params) => {
+                                sender.send(Box::new(|io: &mut Io| {
+                                    dispatch::send_notification::<req::PublishDiagnostics>(io, params)
+                                }))
+                            }
+                        }
+                    });
                     Ok(())
                 })?;
                 dispatch::handle_notification::<req::DidChangeTextDocument, _>(&mut not, |mut params| {
@@ -217,11 +233,30 @@ fn main_loop(
                         .ok_or_else(|| format_err!("empty changes"))?
                         .text;
                     world.change_overlay(path, Some(text));
+                    let world = world.snapshot();
+                    let sender = sender.clone();
+                    let uri = params.text_document.uri;
+                    pool.execute(move || {
+                        match publish_diagnostics(world, uri) {
+                            Err(e) => {
+                                error!("failed to compute diagnostics: {:?}", e)
+                            }
+                            Ok(params) => {
+                                sender.send(Box::new(|io: &mut Io| {
+                                    dispatch::send_notification::<req::PublishDiagnostics>(io, params)
+                                }))
+                            }
+                        }
+                    });
                     Ok(())
                 })?;
                 dispatch::handle_notification::<req::DidCloseTextDocument, _>(&mut not, |params| {
                     let path = params.text_document.file_path()?;
                     world.change_overlay(path, None);
+                    dispatch::send_notification::<req::PublishDiagnostics>(io, req::PublishDiagnosticsParams {
+                        uri: params.text_document.uri,
+                        diagnostics: Vec::new(),
+                    })?;
                     Ok(())
                 })?;
 
@@ -252,21 +287,25 @@ trait FilePath {
 
 impl FilePath for TextDocumentItem {
     fn file_path(&self) -> Result<PathBuf> {
-        self.uri.to_file_path()
-            .map_err(|()| format_err!("invalid uri: {}", self.uri))
+        self.uri.file_path()
     }
 }
 
 impl FilePath for VersionedTextDocumentIdentifier {
     fn file_path(&self) -> Result<PathBuf> {
-        self.uri.to_file_path()
-            .map_err(|()| format_err!("invalid uri: {}", self.uri))
+        self.uri.file_path()
     }
 }
 
 impl FilePath for TextDocumentIdentifier {
     fn file_path(&self) -> Result<PathBuf> {
-        self.uri.to_file_path()
-            .map_err(|()| format_err!("invalid uri: {}", self.uri))
+        self.uri.file_path()
+    }
+}
+
+impl FilePath for ::url::Url {
+    fn file_path(&self) -> Result<PathBuf> {
+        self.to_file_path()
+            .map_err(|()| format_err!("invalid uri: {}", self))
     }
 }
diff --git a/crates/server/src/req.rs b/crates/server/src/req.rs
index 4e588159bc..64e7ef4ae5 100644
--- a/crates/server/src/req.rs
+++ b/crates/server/src/req.rs
@@ -2,7 +2,7 @@ use languageserver_types::{TextDocumentIdentifier, Range};
 
 pub use languageserver_types::{
     request::*, notification::*,
-    InitializeResult,
+    InitializeResult, PublishDiagnosticsParams
 };
 
 pub enum SyntaxTree {}