diff --git a/src/moepkg/callhierarchyviewer.nim b/src/moepkg/callhierarchyviewer.nim
index c1164fa27..8de2d0c01 100644
--- a/src/moepkg/callhierarchyviewer.nim
+++ b/src/moepkg/callhierarchyviewer.nim
@@ -89,7 +89,7 @@ proc incomingCalls(status: var EditorStatus) =
   let infoIndex =
     currentMainWindowNode.currentLine - CallHierarchyViewHeaderLength
 
-  let r = status.lspClients[langId.get].textDocumentIncomingCalls(
+  let r = waitFor status.lspClients[langId.get].textDocumentIncomingCalls(
     currentBufStatus.id,
     currentBufStatus.callHierarchyInfo.items[infoIndex])
   if r.isErr:
@@ -109,7 +109,7 @@ proc outgoingCalls(status: var EditorStatus) =
   let infoIndex =
     currentMainWindowNode.currentLine - CallHierarchyViewHeaderLength
 
-  let r = status.lspClients[langId.get].textDocumentOutgoingCalls(
+  let r = waitFor status.lspClients[langId.get].textDocumentOutgoingCalls(
     currentBufStatus.id,
     currentBufStatus.callHierarchyInfo.items[infoIndex])
   if r.isErr:
diff --git a/src/moepkg/editorstatus.nim b/src/moepkg/editorstatus.nim
index a2af1b137..33b1bd5d9 100644
--- a/src/moepkg/editorstatus.nim
+++ b/src/moepkg/editorstatus.nim
@@ -306,7 +306,7 @@ proc cancelLspForegroundRequest*(
     if c.isInitialized:
       let fgRes = c.getForegroundWaitingResponse(bufferId)
       if fgRes.isSome:
-        let err = c.cancelForegroundRequest(bufferId)
+        let err = waitFor c.cancelForegroundRequest(bufferId)
         if err.isOk:
           return Result[LspMethod, string].ok fgRes.get.lspMethod
         else:
@@ -342,7 +342,7 @@ proc lspInitialize*(
 
     if not status.lspClients.contains(langId):
       # Init a LSP client and start a LSP server.
-      var c = initLspClient(
+      var c = waitFor initLspClient(
         $status.settings.lsp.languages[langId].command)
       if c.isErr:
         return Result[(), string].err c.error
@@ -350,7 +350,7 @@ proc lspInitialize*(
       status.lspClients[langId] = c.get
 
     # Initialize request
-    let err = status.lspClients[langId].initialize(
+    let err = waitFor status.lspClients[langId].initialize(
       status.bufStatus[^1].id,
       initInitializeParams(
         status.lspClients[langId].serverName,
@@ -446,7 +446,7 @@ proc addNewBuffer*(
                status.settings.lsp.languages.contains(newBufStatus.langId):
                  if status.lspClients.contains(newBufStatus.langId):
                    # textDocument/didOpen notification
-                   let err = lspClient.textDocumentDidOpen(
+                   let err = waitFor lspClient.textDocumentDidOpen(
                      $newBufStatus.path.absolutePath,
                      newBufStatus.langId,
                      newBufStatus.buffer.toString)
@@ -689,7 +689,7 @@ proc sendLspSemanticTokenRequest*(c: var LspClient, b: BufferStatus) =
 
   block:
     # Cancel before completion request.
-    let err = c.cancelRequest(
+    let err = waitFor c.cancelRequest(
       b.id,
       LspMethod.textDocumentSemanticTokensFull)
     if err.isErr:
@@ -697,7 +697,7 @@ proc sendLspSemanticTokenRequest*(c: var LspClient, b: BufferStatus) =
 
   block:
     # Send a textDocument/semanticTokens request to the LSP server.
-    let err = c.textDocumentSemanticTokens(b.id, $b.absolutePath)
+    let err = waitFor c.textDocumentSemanticTokens(b.id, $b.absolutePath)
     if err.isErr:
       error fmt"lsp: {err.error}"
 
@@ -710,7 +710,7 @@ proc sendLspInlayHintRequest*(
 
     block:
       # Cancel before inlayHint request.
-      let err = c.cancelRequest(b.id, LspMethod.textDocumentInlayHint)
+      let err = waitFor c.cancelRequest(b.id, LspMethod.textDocumentInlayHint)
       if err.isErr: error fmt"lsp: {err.error}"
 
     # Calc range from all views.
@@ -731,7 +731,7 @@ proc sendLspInlayHintRequest*(
           if b.buffer[last].high >= 0: b.buffer[last].high
           else: 0
 
-    let err = c.textDocumentInlayHint(b.id, $b.absolutePath, hintRange)
+    let err = waitFor c.textDocumentInlayHint(b.id, $b.absolutePath, hintRange)
     if err.isErr: error fmt"lsp: {err.error}"
 
     b.inlayHints.range = Range(
@@ -747,7 +747,7 @@ proc sendLspInlineValueRequest*(
 
     block:
       # Cancel before inlineValue request.
-      let err = c.cancelRequest(b.id, LspMethod.textDocumentInlineValue)
+      let err = waitFor c.cancelRequest(b.id, LspMethod.textDocumentInlineValue)
       if err.isErr: error fmt"lsp: {err.error}"
 
     # Calc range from all views.
@@ -768,7 +768,7 @@ proc sendLspInlineValueRequest*(
           if b.buffer[last].high >= 0: b.buffer[last].high
           else: 0
 
-    let err = c.textDocumentInlineValue(b.id, $b.absolutePath, valueRange)
+    let err = waitFor c.textDocumentInlineValue(b.id, $b.absolutePath, valueRange)
     if err.isErr: error fmt"lsp: {err.error}"
 
     b.inlineValues.range = Range(
@@ -778,7 +778,7 @@ proc sendLspInlineValueRequest*(
 proc sendLspCodeLens*(c: var LspClient, b: BufferStatus) =
   ## Send textDocument/codeLens requests to the LSP server.
 
-  let err = c.textDocumentCodeLens(b.id, $b.absolutePath)
+  let err = waitFor c.textDocumentCodeLens(b.id, $b.absolutePath)
   if err.isErr:
     error fmt"lsp: {err.error}"
 
@@ -832,7 +832,7 @@ proc updateSyntaxHighlightings(status: EditorStatus) =
 
         if isSendDidChange():
           # Send a textDocument/didChange notification to the LSP server.
-          let err = client.textDocumentDidChange(
+          let err = waitFor client.textDocumentDidChange(
             b.version,
             absPath,
             b.buffer.toString)
@@ -1527,7 +1527,7 @@ proc autoSave(status: var EditorStatus) =
 
       if bufStatus.isEditMode and status.lspClients.contains(bufStatus.langId):
         # Send textDocument/didSave notify to the LSP server.
-        let err = status.lspClients[bufStatus.langId].textDocumentDidSave(
+        let err = waitFor status.lspClients[bufStatus.langId].textDocumentDidSave(
           bufStatus.version,
           $bufStatus.path.absolutePath,
           $bufStatus.buffer)
diff --git a/src/moepkg/exmode.nim b/src/moepkg/exmode.nim
index 54b3792bb..3fae9a8cf 100644
--- a/src/moepkg/exmode.nim
+++ b/src/moepkg/exmode.nim
@@ -774,7 +774,7 @@ proc writeCommand(status: var EditorStatus, path: Runes) =
 
     if status.lspClients.contains(currentBufStatus.langId):
       # Send textDocument/didSave notify to the LSP server.
-      let err = lspClient.textDocumentDidSave(
+      let err = waitFor lspClient.textDocumentDidSave(
         currentBufStatus.version,
         $currentBufStatus.path.absolutePath,
         $currentBufStatus.buffer)
@@ -874,7 +874,7 @@ proc writeAndQuitCommand(status: var EditorStatus) =
 
   if status.lspClients.contains(currentBufStatus.langId):
     # Send textDocument/didSave notify to the LSP server.
-    let err = lspClient.textDocumentDidSave(
+    let err = waitFor lspClient.textDocumentDidSave(
       currentBufStatus.version,
       $currentBufStatus.path.absolutePath,
       $currentBufStatus.buffer)
@@ -1133,7 +1133,7 @@ proc lspExecuteCommand(status: var EditorStatus, command: seq[Runes]) =
     status.commandLine.writeLspExecuteCommandError("unknow command")
     return
 
-  let r = lspClient.workspaceExecuteCommand(
+  let r = waitFor lspClient.workspaceExecuteCommand(
     currentBufStatus.id,
     lspCommand,
     %*command[1 .. ^1].mapIt($it))
@@ -1154,7 +1154,7 @@ proc lspFoldingRange(status: var EditorStatus) =
       "folding range is unavailable")
     return
 
-  let r = lspClient.textDocumentFoldingRange(
+  let r = waitFor lspClient.textDocumentFoldingRange(
     currentBufStatus.id,
     $currentBufStatus.absolutePath)
   if r.isErr:
@@ -1167,7 +1167,7 @@ proc lspRestartClient(status: var EditorStatus) =
     status.commandLine.writeLspError("Client not found")
     return
 
-  let r = lspClient.restart
+  let r = waitFor lspClient.restart
   if r.isOk:
     status.commandLine.writeStandard(fmt"lsp: restarted client: {lspClient.serverName}")
   else:
@@ -1176,7 +1176,7 @@ proc lspRestartClient(status: var EditorStatus) =
   let langId = currentBufStatus.langId
   for b in status.bufStatus:
     if b.langId == langId:
-      let r = lspClient.initialize(
+      let r = waitFor lspClient.initialize(
         status.bufStatus[^1].id,
         initInitializeParams(
           lspClient.serverName,
@@ -1200,7 +1200,7 @@ proc lspDocumentFormatting(status: var EditorStatus) =
     insertSpaces: true,
     insertFinalNewline: some(true))
 
-  let r = lspClient.textDocumentFormatting(
+  let r = waitFor lspClient.textDocumentFormatting(
     currentBufStatus.id,
     $currentBufStatus.absolutePath,
     options)
diff --git a/src/moepkg/insertmode.nim b/src/moepkg/insertmode.nim
index fb1ed4c05..88c0cae64 100644
--- a/src/moepkg/insertmode.nim
+++ b/src/moepkg/insertmode.nim
@@ -88,7 +88,7 @@ proc sendDidChangeNotify(status: var EditorStatus): Result[(), string] =
     first: currentMainWindowNode.bufferPosition,
     last: currentMainWindowNode.bufferPosition)
 
-  let err = lspClient.textDocumentDidChange(
+  let err = waitFor lspClient.textDocumentDidChange(
     currentBufStatus.version,
     $currentBufStatus.path.absolutePath,
     currentBufStatus.buffer.toString,
@@ -111,7 +111,7 @@ proc sendCompletionRequest(
     block:
       let isIncompleteTrigger = status.completionWindow.isSome
 
-      let err = lspClient.textDocumentCompletion(
+      let err = waitFor lspClient.textDocumentCompletion(
         currentBufStatus.id,
         $currentBufStatus.path.absolutePath,
         currentMainWindowNode.bufferPosition,
@@ -141,7 +141,7 @@ proc sendSignatureHelpRequest(
           if r.isSome: SignatureHelpTriggerKind.TriggerCharacter
           else: SignatureHelpTriggerKind.Invoked
 
-      let err = lspClient.textDocumentSignatureHelp(
+      let err = waitFor lspClient.textDocumentSignatureHelp(
         currentBufStatus.id,
         $currentBufStatus.path.absolutePath,
         currentMainWindowNode.bufferPosition,
diff --git a/src/moepkg/lsp/client.nim b/src/moepkg/lsp/client.nim
index 7a73250a9..dd89bf3d2 100644
--- a/src/moepkg/lsp/client.nim
+++ b/src/moepkg/lsp/client.nim
@@ -37,6 +37,8 @@ import jsonrpc, utils, completion, progress, hover, semantictoken, inlayhint,
        executecommand, selectionrange, documentsymbol, inlinevalue,
        signaturehelp, formatting
 
+export chronos
+
 type
   LspError* = object
     code*: int
@@ -147,38 +149,38 @@ proc kill*(c: LspClient): Result[(), string] =
 
 template isInitialized*(c: LspClient): bool = c.capabilities.isSome
 
-template addRequestLog*(c: var LspClient, m: JsonNode) =
+template addRequestLog*(c: LspClient, m: JsonNode) =
   c.log.add LspMessage(
     timestamp: now(),
     kind: LspMessageKind.request,
     message: m)
 
-template addResponseLog*(c: var LspClient, m: JsonNode) =
+template addResponseLog*(c: LspClient, m: JsonNode) =
   c.log.add LspMessage(
     timestamp: now(),
     kind: LspMessageKind.response,
     message: m)
 
-template addNotifyFromClientLog*(c: var LspClient, m: JsonNode) =
+template addNotifyFromClientLog*(c: LspClient, m: JsonNode) =
   c.log.add LspMessage(
     timestamp: now(),
     kind: LspMessageKind.notifyFromClient,
     message: m)
 
-template addNotifyFromServerLog*(c: var LspClient, m: JsonNode) =
+template addNotifyFromServerLog*(c: LspClient, m: JsonNode) =
   c.log.add LspMessage(
     timestamp: now(),
     kind: LspMessageKind.notifyFromServer,
     message: m)
 
-proc createProgress*(c: var LspClient, token: ProgressToken) =
+proc createProgress*(c: LspClient, token: ProgressToken) =
   ## Add a new progress to the `LspClint.progress`.
 
   if not c.progress.contains(token):
     c.progress[token] = ProgressReport(state: ProgressState.create)
 
 proc beginProgress*(
-  c: var LspClient,
+  c: LspClient,
   token: ProgressToken,
   p: WorkDoneProgressBegin): Result[(), string] =
     ## Begin the progress in the `LspClint.progress`.
@@ -196,7 +198,7 @@ proc beginProgress*(
     return Result[(), string].ok ()
 
 proc reportProgress*(
-  c: var LspClient,
+  c: LspClient,
   token: ProgressToken,
   report: WorkDoneProgressReport): Result[(), string] =
     ## Update the progress in the `LspClint.progress`.
@@ -215,7 +217,7 @@ proc reportProgress*(
     return Result[(), string].ok ()
 
 proc endProgress*(
-  c: var LspClient,
+  c: LspClient,
   token: ProgressToken,
   p: WorkDoneProgressEnd): Result[(), string] =
     ## End the progress in the `LspClint.progress`.
@@ -230,7 +232,7 @@ proc endProgress*(
 
     return Result[(), string].ok ()
 
-proc delProgress*(c: var LspClient, token: ProgressToken): Result[(), string] =
+proc delProgress*(c: LspClient, token: ProgressToken): Result[(), string] =
   ## Delete the progress from the `LspClint.progress`.
 
   if not c.progress.contains(token):
@@ -252,10 +254,10 @@ proc readable*(c: LspClient, timeout: int = 1): LspClientReadableResult =
   return LspClientReadableResult.ok r == 1
 
 proc request(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   lspMethod: LspMethod,
-  params: JsonNode): Result[int, string] =
+  params: JsonNode): Future[Result[int, string]] {.async.} =
     ## Send a request to the LSP server and set to waitingResponse.
     ## Return request id.
 
@@ -264,7 +266,7 @@ proc request(
 
     c.addRequestLog(req)
 
-    let r = c.serverProcess.stdinStream.sendRequest(req)
+    let r = await c.serverStreams.input.sendRequest(req)
     if r.isErr:
       return Result[int, string].err r.error
 
@@ -276,21 +278,21 @@ proc request(
     return Result[int, string].ok c.lastId
 
 proc notify(
-  c: var LspClient,
+  c: LspClient,
   lspMethod: LspMethod,
-  params: JsonNode): Result[(), string] {.inline.} =
+  params: JsonNode): Future[Result[(), string]] {.async.} =
     ## Send a notification to the LSP server.
 
     let notify = newNotify(lspMethod.toLspMethodStr, params)
 
     c.addNotifyFromClientLog(notify)
 
-    return c.serverProcess.stdinStream.sendNotify(notify)
+    return await c.serverStreams.input.sendNotify(notify)
 
-proc read*(c: var LspClient): JsonRpcResponseResult =
+proc read*(c: LspClient): Future[JsonRpcResponseResult] {.async.} =
   ## Read a response from the LSP server.
 
-  let r = jsonrpc.read(c.serverStreams.output.stream)
+  let r = await read(c.serverStreams.output)
   if r.isOk:
     return JsonRpcResponseResult.ok r.get
   else:
@@ -311,7 +313,7 @@ proc parseLspError*(res: JsonNode): LspErrorParseResult =
     return LspErrorParseResult.err fmt"Invalid error: {$res}"
 
 proc setWaitResponse*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   lspMethod: LspMethod) {.inline.} =
 
@@ -320,17 +322,17 @@ proc setWaitResponse*(
       requestId: c.lastId,
       lspMethod: lspMethod)
 
-proc deleteWaitingResponse*(c: var LspClient, id: RequestId) {.inline.} =
+proc deleteWaitingResponse*(c: LspClient, id: RequestId) {.inline.} =
   if c.waitingResponses.contains(id):
     c.waitingResponses.del(id)
 
-proc isWaitingResponse*(c: var LspClient, bufferId: int): bool {.inline.} =
+proc isWaitingResponse*(c: LspClient, bufferId: int): bool {.inline.} =
   for v in c.waitingResponses.values:
     if v.bufferId == bufferId:
       return true
 
 proc isWaitingResponse*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   lspMethod: LspMethod): bool {.inline.} =
 
@@ -339,7 +341,7 @@ proc isWaitingResponse*(
         return true
 
 proc isWaitingForegroundResponse*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int): bool {.inline.} =
 
     for v in c.waitingResponses.values:
@@ -362,7 +364,7 @@ proc getWaitingResponse*(
       if v.bufferId == bufferId and v.lspMethod == lspMethod:
         return some(v)
 
-proc getLatestWaitingResponse*(c: var LspClient): Option[WaitLspResponse] =
+proc getLatestWaitingResponse*(c: LspClient): Option[WaitLspResponse] =
   var latest = -1
   for k in c.waitingResponses.keys:
     if k > latest: latest = k
@@ -371,7 +373,7 @@ proc getLatestWaitingResponse*(c: var LspClient): Option[WaitLspResponse] =
     return some(c.waitingResponses[latest])
 
 proc getForegroundWaitingResponse*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int): Option[WaitLspResponse] =
 
     for v in c.waitingResponses.values:
@@ -381,7 +383,7 @@ proc getForegroundWaitingResponse*(
 template getFdStdout(c: LspClient): cint =
   c.serverStreams.output.stream.tsource.fd.cint
 
-proc initLspClient*(command: string): initLspClientResult =
+proc initLspClient*(command: string): Future[initLspClientResult] {.async.} =
   ## Start a LSP server process and init streams.
 
   const
@@ -397,7 +399,7 @@ proc initLspClient*(command: string): initLspClientResult =
   var c = LspClient()
 
   try:
-    c.serverProcess = waitFor startProcess(
+    c.serverProcess = await startProcess(
       commandSplit[0],
       WorkingDir,
       args,
@@ -426,7 +428,7 @@ proc initLspClient*(command: string): initLspClientResult =
 
   return initLspClientResult.ok c
 
-proc restart*(c: var LspClient): LspRestartClientResult =
+proc restart*(c: LspClient): Future[LspRestartClientResult] {.async.} =
   ## Restart the LSP server process.
   ## Logs will be taken over.
 
@@ -434,11 +436,42 @@ proc restart*(c: var LspClient): LspRestartClientResult =
 
   let beforeLog = c.log
 
-  var newClient = initLspClient(c.command)
-  if newClient.isErr:
-    return LspRestartClientResult.err newClient.error
+  const
+    WorkingDir = ""
+    Env = nil
+  let
+    commandSplit = c.command.split(' ')
+    args =
+      if commandSplit.len > 1: commandSplit[1 .. ^1]
+      else: @[]
+    opts: set[AsyncProcessOption] = {UsePath, EvalCommand, StdErrToStdOut}
+
+  try:
+    c.serverProcess = await startProcess(
+      commandSplit[0],
+      WorkingDir,
+      args,
+      Env,
+      opts,
+      stdoutHandle = AsyncProcess.Pipe,
+      stdinHandle = AsyncProcess.Pipe)
+  except CatchableError as e:
+    return LspRestartClientResult.err fmt"server start failed: {e.msg}"
+
+  c.serverStreams = Streams(
+    input: InputStream(stream: c.serverProcess.stdinStream),
+    output: OutputStream(stream: c.serverProcess.stdoutStream))
+
+  block:
+    # Init pollFd.
+    c.pollFd.addr.zeroMem(sizeof(c.pollFd))
+
+    # Registers fd and events.
+    c.pollFd.fd = c.getFdStdout
+    c.pollFd.events = POLLIN or POLLERR
+
+  c.serverName = commandSplit[0]
 
-  c = newClient.get
   c.log = beforeLog
 
   return LspRestartClientResult.ok ()
@@ -585,7 +618,7 @@ proc initInitializeParams*(
     )
 
 proc setCapabilities(
-  c: var LspClient,
+  c: LspClient,
   initResult: InitializeResult,
   settings: LspFeatureSettings) =
     ## Set server capabilities to the LspClient from InitializeResult.
@@ -880,9 +913,9 @@ proc setCapabilities(
     c.capabilities = some(capabilities)
 
 proc cancelRequest*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  requestId: RequestId): LspSendNotifyResult =
+  requestId: RequestId): Future[LspSendNotifyResult] {.async.} =
     ## Send a cancelRequest notification to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#cancelRequest
 
@@ -894,45 +927,45 @@ proc cancelRequest*(
 
     let params = %* CancelParams(id: some(%*requestId))
 
-    let err = c.notify(LspMethod.cancelRequest, params)
+    let err = await c.notify(LspMethod.cancelRequest, params)
     if err.isErr:
       return LspSendNotifyResult.err fmt"cancelRequest notification failed: {err.error}"
 
     return LspSendNotifyResult.ok ()
 
 proc cancelRequest*(
-  c: var LspClient,
-  waitRes: WaitLspResponse): LspSendRequestResult {.inline.} =
+  c: LspClient,
+  waitRes: WaitLspResponse): Future[LspSendRequestResult] {.async.} =
     ## Send a cancel request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#cancelRequest
 
-    c.cancelRequest(waitRes.bufferId, waitRes.requestId)
+    return await c.cancelRequest(waitRes.bufferId, waitRes.requestId)
 
 proc cancelRequest*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  lspMethod: LspMethod): LspSendRequestResult =
+  lspMethod: LspMethod): Future[LspSendRequestResult] {.async.} =
 
     let w = c.getWaitingResponse(bufferId, lspMethod)
     if w.isSome:
-      return c.cancelRequest(w.get)
+      return await c.cancelRequest(w.get)
 
     return LspSendRequestResult.ok ()
 
 proc cancelForegroundRequest*(
-  c: var LspClient,
-  bufferId: int): LspSendRequestResult =
+  c: LspClient,
+  bufferId: int): Future[LspSendRequestResult] {.async.} =
 
     let w = c.getForegroundWaitingResponse(bufferId)
     if w.isSome:
-      return c.cancelRequest(w.get)
+      return await c.cancelRequest(w.get)
 
     return LspSendRequestResult.ok ()
 
 proc initialize*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  initParams: InitializeParams): LspSendRequestResult =
+  initParams: InitializeParams): Future[LspSendRequestResult] {.async.} =
     ## Send a initialize request to the server and check server capabilities.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialize
 
@@ -942,14 +975,14 @@ proc initialize*(
 
     let params = %* initParams
 
-    let r = c.request(bufferId, LspMethod.initialize, params)
+    let r = await c.request(bufferId, LspMethod.initialize, params)
     if r.isErr:
       return LspSendRequestResult.err fmt"Initialize request failed: {r.error}"
 
     return LspSendRequestResult.ok ()
 
 proc initCapacities*(
-  c: var LspClient,
+  c: LspClient,
   settings: LspFeatureSettings,
   res: JsonNode): LspInitializeResult =
 
@@ -966,7 +999,7 @@ proc initCapacities*(
 
     return LspInitializeResult.ok ()
 
-proc initialized*(c: var LspClient): LspSendNotifyResult =
+proc initialized*(c: LspClient): Future[LspSendNotifyResult] {.async.} =
   ## Send a initialized notification to the server.
   ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#initialized
 
@@ -976,13 +1009,13 @@ proc initialized*(c: var LspClient): LspSendNotifyResult =
 
   let params = %* {}
 
-  let err = c.notify(LspMethod.initialized, params)
+  let err = await c.notify(LspMethod.initialized, params)
   if err.isErr:
     return LspSendNotifyResult.err fmt"Invalid notification failed: {err.error}"
 
   return LspSendNotifyResult.ok ()
 
-proc shutdown*(c: var LspClient, bufferId: int): LspSendNotifyResult =
+proc shutdown*(c: LspClient, bufferId: int): Future[LspSendNotifyResult] {.async.} =
   ## Send a shutdown request to the server.
   ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#shutdown
 
@@ -993,14 +1026,14 @@ proc shutdown*(c: var LspClient, bufferId: int): LspSendNotifyResult =
   if not c.isInitialized:
     return R[(), string].err "lsp unavailable"
 
-  let id = c.request(bufferId, LspMethod.shutdown, %*{})
+  let id = await c.request(bufferId, LspMethod.shutdown, %*{})
   if id.isErr:
     return LspSendNotifyResult.err "Shutdown request failed: {id.error}"
 
   return LspSendNotifyResult.ok ()
 
 proc workspaceDidChangeConfiguration*(
-  c: var LspClient): LspSendNotifyResult =
+  c: LspClient): Future[LspSendNotifyResult] {.async.} =
     ## Send a workspace/didChangeConfiguration notification to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_didChangeConfiguration
 
@@ -1013,7 +1046,7 @@ proc workspaceDidChangeConfiguration*(
 
     let params = %* DidChangeConfigurationParams()
 
-    let err = c.notify(LspMethod.workspaceDidChangeConfiguration, params)
+    let err = await c.notify(LspMethod.workspaceDidChangeConfiguration, params)
     if err.isErr:
       return LspSendNotifyResult.err fmt"Invalid workspace/didChangeConfiguration failed: {err.error}"
 
@@ -1030,8 +1063,8 @@ proc initTextDocumentDidOpenParams(
         text: text))
 
 proc textDocumentDidOpen*(
-  c: var LspClient,
-  path, languageId, text: string): LspSendNotifyResult =
+  c: LspClient,
+  path, languageId, text: string): Future[LspSendNotifyResult] {.async.} =
     ## Send a textDocument/didOpen notification to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didOpen
 
@@ -1047,7 +1080,7 @@ proc textDocumentDidOpen*(
       languageId,
       text)
 
-    let err = c.notify(LspMethod.textDocumentDidOpen, params)
+    let err = await c.notify(LspMethod.textDocumentDidOpen, params)
     if err.isErr:
       return LspSendNotifyResult.err fmt"textDocument/didOpen notification failed: {err.error}"
 
@@ -1078,10 +1111,10 @@ proc initTextDocumentDidChangeParams(
         contentChanges: @[TextDocumentContentChangeEvent(text: text)])
 
 proc textDocumentDidChange*(
-  c: var LspClient,
+  c: LspClient,
   version: Natural,
   path, text: string,
-  range: Option[BufferRange] = none(BufferRange)): LspSendNotifyResult =
+  range: Option[BufferRange] = none(BufferRange)): Future[LspSendNotifyResult] {.async.} =
     ## Send a textDocument/didChange notification to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didChange
 
@@ -1094,7 +1127,7 @@ proc textDocumentDidChange*(
 
     let params = %* initTextDocumentDidChangeParams(version, path, text, range)
 
-    let err = c.notify(LspMethod.textDocumentDidChange, params)
+    let err = await c.notify(LspMethod.textDocumentDidChange, params)
     if err.isErr:
       return LspSendNotifyResult.err fmt"textDocument/didChange notification failed: {err.error}"
 
@@ -1111,9 +1144,9 @@ proc initTextDocumentDidSaveParams(
       text: some(text))
 
 proc textDocumentDidSave*(
-  c: var LspClient,
+  c: LspClient,
   version: Natural,
-  path, text: string): LspSendNotifyResult =
+  path, text: string): Future[LspSendNotifyResult] {.async.} =
     ## Send a textDocument/didSave notification to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didSave
 
@@ -1126,7 +1159,7 @@ proc textDocumentDidSave*(
 
     let params = %* initTextDocumentDidSaveParams(version, path, text)
 
-    let err = c.notify(LspMethod.textDocumentDidChange, params)
+    let err = await c.notify(LspMethod.textDocumentDidChange, params)
     if err.isErr:
       return LspSendNotifyResult.err fmt"textDocument/didSave notification failed: {err.error}"
 
@@ -1139,8 +1172,8 @@ proc initTextDocumentDidClose(
       textDocument: TextDocumentIdentifier(uri: path.pathToUri))
 
 proc textDocumentDidClose*(
-  c: var LspClient,
-  text: string): LspSendNotifyResult =
+  c: LspClient,
+  text: string): Future[LspSendNotifyResult] {.async.} =
     ## Send a textDocument/didClose notification to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_didClose
 
@@ -1150,17 +1183,17 @@ proc textDocumentDidClose*(
 
     let params = %* initTextDocumentDidClose(text)
 
-    let err = c.notify(LspMethod.textDocumentDidClose, params)
+    let err = await c.notify(LspMethod.textDocumentDidClose, params)
     if err.isErr:
       return LspSendNotifyResult.err fmt"textDocument/didClose notification failed: {err.error}"
 
     return LspSendNotifyResult.ok ()
 
 proc textDocumentHover*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  position: BufferPosition): LspSendRequestResult =
+  position: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/hover request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_hover
 
@@ -1175,19 +1208,19 @@ proc textDocumentHover*(
       return R[(), string].err "textDocument/hover unavailable"
 
     let params = %* initHoverParams(path, position.toLspPosition)
-    let id = c.request(bufferId, LspMethod.textDocumentHover, params)
+    let id = await c.request(bufferId, LspMethod.textDocumentHover, params)
     if id.isErr:
       return R[(), string].err fmt"textDocument/hover request failed: {id.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentCompletion*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
   position: BufferPosition,
   isIncompleteTrigger: bool,
-  character: string): LspSendRequestResult =
+  character: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/completion request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_completion
 
@@ -1208,16 +1241,16 @@ proc textDocumentCompletion*(
       isIncompleteTrigger,
       character)
 
-    let id = c.request(bufferId, LspMethod.textDocumentCompletion, params)
+    let id = await c.request(bufferId, LspMethod.textDocumentCompletion, params)
     if id.isErr:
       return R[(), string].err fmt"textDocument/completion request failed: {id.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentSemanticTokens*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  path: string): LspSendRequestResult =
+  path: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/semanticTokens/full request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_semanticTokens
 
@@ -1233,17 +1266,17 @@ proc textDocumentSemanticTokens*(
 
     let params = %* initSemanticTokensParams(path)
 
-    let id = c.request(bufferId, LspMethod.textDocumentSemanticTokensFull, params)
+    let id = await c.request(bufferId, LspMethod.textDocumentSemanticTokensFull, params)
     if id.isErr:
       return R[(), string].err fmt"textDocument/semanticTokens/full request failed: {id.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentInlayHint*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  range: BufferRange): LspSendRequestResult =
+  range: BufferRange): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/inlayHint request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_inlayHint
 
@@ -1259,17 +1292,17 @@ proc textDocumentInlayHint*(
 
     let params = %* initInlayHintParams(path, range)
 
-    let r = c.request(bufferId, LspMethod.textDocumentInlayHint, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentInlayHint, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/inlayHint request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentDefinition*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.}  =
     ## Send a textDocument/definition request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_definition
 
@@ -1285,17 +1318,17 @@ proc textDocumentDefinition*(
 
     let params = %* initDefinitionParams(path, posi)
 
-    let r = c.request(bufferId, LspMethod.textDocumentDefinition, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentDefinition, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/definition request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentReferences*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/references request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_references
 
@@ -1311,18 +1344,18 @@ proc textDocumentReferences*(
 
     let params = %* initReferenceParams(path, posi.toLspPosition)
 
-    let r = c.request(bufferId, LspMethod.textDocumentReferences, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentReferences, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/references request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentRename*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
   posi: BufferPosition,
-  newName: string): LspSendRequestResult =
+  newName: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/rename request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_rename
 
@@ -1338,17 +1371,17 @@ proc textDocumentRename*(
 
     let params = %* initRenameParams(path, posi.toLspPosition, newName)
 
-    let r = c.request(bufferId, LspMethod.textDocumentRename, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentRename, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/rename request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentTypeDefinition*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/typeDefinition request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_typeDefinition
 
@@ -1364,17 +1397,17 @@ proc textDocumentTypeDefinition*(
 
     let params = %* initTypeDefinitionParams(path, posi)
 
-    let r = c.request(bufferId, LspMethod.textDocumentTypeDefinition, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentTypeDefinition, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/typeDefinition request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentImplementation*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/implementation request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_implementation
 
@@ -1390,17 +1423,17 @@ proc textDocumentImplementation*(
 
     let params = %* initImplementationParams(path, posi)
 
-    let r = c.request(bufferId, LspMethod.textDocumentImplementation, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentImplementation, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/implementation request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentDeclaration*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/declaration request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_declaration
 
@@ -1416,17 +1449,17 @@ proc textDocumentDeclaration*(
 
     let params = %* initImplementationParams(path, posi)
 
-    let r = c.request(bufferId, LspMethod.textDocumentDeclaration, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentDeclaration, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/declaration request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentPrepareCallHierarchy*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/prepareCallHierarchy request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_prepareCallHierarchy
 
@@ -1442,16 +1475,16 @@ proc textDocumentPrepareCallHierarchy*(
 
     let params = %* initCallHierarchyPrepareParams(path, posi)
 
-    let r = c.request(bufferId, LspMethod.textDocumentPrepareCallHierarchy, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentPrepareCallHierarchy, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/prepareCallHierarchy request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentIncomingCalls*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  item: CallHierarchyItem): LspSendRequestResult =
+  item: CallHierarchyItem): Future[LspSendRequestResult] {.async.} =
     ## Send a callHierarchy/incomingCalls request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#callHierarchy_incomingCalls
 
@@ -1467,16 +1500,16 @@ proc textDocumentIncomingCalls*(
 
     let params = %* initCallHierarchyIncomingParams(item)
 
-    let r = c.request(bufferId, LspMethod.callHierarchyIncomingCalls, params)
+    let r = await c.request(bufferId, LspMethod.callHierarchyIncomingCalls, params)
     if r.isErr:
       return R[(), string].err fmt"callHierarchy/incomingCalls request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentOutgoingCalls*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  item: CallHierarchyItem): LspSendRequestResult =
+  item: CallHierarchyItem): Future[LspSendRequestResult] {.async.} =
     ## Send a callHierarchy/outgoingCalls request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#callHierarchy_outgoingCalls
 
@@ -1492,17 +1525,17 @@ proc textDocumentOutgoingCalls*(
 
     let params = %* initCallHierarchyOutgoingParams(item)
 
-    let r = c.request(bufferId, LspMethod.callHierarchyOutgoingCalls, params)
+    let r = await c.request(bufferId, LspMethod.callHierarchyOutgoingCalls, params)
     if r.isErr:
       return R[(), string].err fmt"callHierarchy/outgoingCalls request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentDocumentHighlight*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  posi: BufferPosition): LspSendRequestResult =
+  posi: BufferPosition): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/documentHighlight request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_documentHighlight
 
@@ -1518,16 +1551,16 @@ proc textDocumentDocumentHighlight*(
 
     let params = %* initDocumentHighlightParamas(path, posi)
 
-    let r = c.request(bufferId, LspMethod.textDocumentDocumentHighlight, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentDocumentHighlight, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/documentHighlight request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentDocumentLink*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  path: string): LspSendRequestResult =
+  path: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/documentLink request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_documentLink
 
@@ -1543,16 +1576,16 @@ proc textDocumentDocumentLink*(
 
     let params = %* initDocumentLinkParams(path)
 
-    let r = c.request(bufferId, LspMethod.textDocumentDocumentLink, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentDocumentLink, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/documentLink request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc documentLinkResolve*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  documentLink: DocumentLink): LspSendRequestResult =
+  documentLink: DocumentLink): Future[LspSendRequestResult] {.async.} =
     ## Send a documentLink/resolve request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#documentLink_resolve
 
@@ -1568,16 +1601,16 @@ proc documentLinkResolve*(
 
     let params = %* documentLink
 
-    let r = c.request(bufferId, LspMethod.textDocumentDocumentLink, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentDocumentLink, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/documentLink request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentCodeLens*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  path: string): LspSendRequestResult =
+  path: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/codeLens request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_codeLens
 
@@ -1593,16 +1626,16 @@ proc textDocumentCodeLens*(
 
     let params = %* initCodeLensParams(path)
 
-    let r = c.request(bufferId, LspMethod.textDocumentCodeLens, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentCodeLens, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/codeLens request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc codeLensResolve*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  codeLens: CodeLens): LspSendRequestResult =
+  codeLens: CodeLens): Future[LspSendRequestResult] {.async.} =
     ## Send a codeLens/resolve request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#codeLens_resolve
 
@@ -1618,17 +1651,17 @@ proc codeLensResolve*(
 
     let params = %* codeLens
 
-    let r = c.request(bufferId, LspMethod.codeLensResolve, params)
+    let r = await c.request(bufferId, LspMethod.codeLensResolve, params)
     if r.isErr:
       return R[(), string].err fmt"codeLens/resolve request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc workspaceExecuteCommand*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   command: string,
-  args: JsonNode): LspSendRequestResult =
+  args: JsonNode): Future[LspSendRequestResult] {.async.} =
     ## Send a workspace/executeCommand request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#command
 
@@ -1644,16 +1677,16 @@ proc workspaceExecuteCommand*(
 
     let params = %* initExecuteCommandParams(command, args)
 
-    let r = c.request(bufferId, LspMethod.workspaceExecuteCommand, params)
+    let r = await c.request(bufferId, LspMethod.workspaceExecuteCommand, params)
     if r.isErr:
       return R[(), string].err fmt"workspace/executeCommand request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentFoldingRange*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  path: string): LspSendRequestResult =
+  path: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/foldingRange request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_foldingRange
 
@@ -1669,17 +1702,17 @@ proc textDocumentFoldingRange*(
 
     let params = %* initFoldingRangeParam(path)
 
-    let r = c.request(bufferId, LspMethod.textDocumentFoldingRange, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentFoldingRange, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/foldingRange request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentSelectionRange*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  positions: seq[BufferPosition]): LspSendRequestResult =
+  positions: seq[BufferPosition]): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/selectionRange request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_selectionRange
 
@@ -1695,16 +1728,16 @@ proc textDocumentSelectionRange*(
 
     let params = %* initSelectionRangeParams(path, positions)
 
-    let r = c.request(bufferId, LspMethod.textDocumentSelectionRange, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentSelectionRange, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/selectionRange request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentDocumentSymbol*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
-  path: string): LspSendRequestResult =
+  path: string): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/symbol request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_documentSymbol
 
@@ -1720,17 +1753,17 @@ proc textDocumentDocumentSymbol*(
 
     let params = %* initDocumentSymbolParams(path)
 
-    let r = c.request(bufferId, LspMethod.textDocumentDocumentSymbol, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentDocumentSymbol, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/documentSymbol request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentInlineValue*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  range: BufferRange): LspSendRequestResult =
+  range: BufferRange): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/inlineValue request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_inlineValue
 
@@ -1750,20 +1783,20 @@ proc textDocumentInlineValue*(
       stoppedLocation: range.toLspRange)
     let params = %* initInlineValueParams(path, range.toLspRange, context)
 
-    let r = c.request(bufferId, LspMethod.textDocumentInlineValue, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentInlineValue, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/inlineValue request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentSignatureHelp*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
   position: BufferPosition,
   kind: SignatureHelpTriggerKind,
   triggerChar: Option[string] = none(string),
-  active: Option[SignatureHelp] = none(SignatureHelp)): LspSendRequestResult =
+  active: Option[SignatureHelp] = none(SignatureHelp)): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/signatureHelp request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_signatureHelp
 
@@ -1784,17 +1817,17 @@ proc textDocumentSignatureHelp*(
       triggerChar,
       active)
 
-    let r = c.request(bufferId, LspMethod.textDocumentSignatureHelp, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentSignatureHelp, params)
     if r.isErr:
       return R[(), string].err fmt"textDocument/signatureHelp request failed: {r.error}"
 
     return R[(), string].ok ()
 
 proc textDocumentFormatting*(
-  c: var LspClient,
+  c: LspClient,
   bufferId: int,
   path: string,
-  options: FormattingOptions): LspSendRequestResult =
+  options: FormattingOptions): Future[LspSendRequestResult] {.async.} =
     ## Send a textDocument/documentFormatting request to the server.
     ## https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_formatting
 
@@ -1810,7 +1843,7 @@ proc textDocumentFormatting*(
 
     let params = %* initDocumentFormattingParams(path, options)
 
-    let r = c.request(bufferId, LspMethod.textDocumentFormatting, params)
+    let r = await c.request(bufferId, LspMethod.textDocumentFormatting, params)
     if r.isErr:
       return
         LspSendRequestResult.err fmt"textDocument/formatting request failed: {r.error}"
diff --git a/src/moepkg/lsp/handler.nim b/src/moepkg/lsp/handler.nim
index 1a206a29f..fff135241 100644
--- a/src/moepkg/lsp/handler.nim
+++ b/src/moepkg/lsp/handler.nim
@@ -121,19 +121,19 @@ proc lspInitialized(
 
     block:
       # Initialized notification
-      let err = lspClient.initialized
+      let err = waitFor lspClient.initialized
       if err.isErr:
         return Result[(), string].err err.error
 
     block:
       # workspace/didChangeConfiguration notification
-      let err = lspClient.workspaceDidChangeConfiguration
+      let err = waitFor lspClient.workspaceDidChangeConfiguration
       if err.isErr:
         return Result[(), string].err err.error
 
     block:
       # textDocument/didOpen notification
-      let err = lspClient.textDocumentDidOpen(
+      let err = waitFor lspClient.textDocumentDidOpen(
         $currentBufStatus.path.absolutePath,
         currentBufStatus.langId,
         currentBufStatus.buffer.toString)
@@ -142,7 +142,7 @@ proc lspInitialized(
 
     block:
       # textDocument/semanticTokens
-      let err = lspClient.textDocumentSemanticTokens(
+      let err = waitFor lspClient.textDocumentSemanticTokens(
         currentBufStatus.id,
         $currentBufStatus.path.absolutePath)
       if err.isErr:
@@ -957,7 +957,7 @@ proc lspDocumentLink(
       return Result[(), string].err "Not found"
 
     if links[0].isResolve:
-      let r = lspClient.documentLinkResolve(currentBufStatus.id, links[0])
+      let r = waitFor lspClient.documentLinkResolve(currentBufStatus.id, links[0])
       if r.isErr:
         return Result[(), string].err r.error
 
@@ -1275,7 +1275,7 @@ proc handleLspResponse*(status: var EditorStatus) =
       status.commandLine.writeLspError("server crashed")
       return
 
-    let resJson = lspClient.read
+    let resJson = waitFor lspClient.read
     if resJson.isErr:
       # Maybe invalid messages. Ignore.
       error fmt"lsp: Invalid message: {resJson}"
diff --git a/src/moepkg/lsp/jsonrpc.nim b/src/moepkg/lsp/jsonrpc.nim
index 022a93eeb..b464df4be 100644
--- a/src/moepkg/lsp/jsonrpc.nim
+++ b/src/moepkg/lsp/jsonrpc.nim
@@ -24,6 +24,8 @@ import pkg/[results, jsony, chronos]
 
 import ../messagelog
 
+export chronos
+
 type
   ReadFrameResult = Result[string, string]
   JsonRpcResponseResult* = Result[JsonNode, string]
@@ -59,25 +61,28 @@ proc isInvalidContentType(s: string, valueStart: int): bool {.inline.} =
 proc isValidJsonRpc(json: JsonNode): bool {.inline.} =
   json.contains("jsonrpc")
 
-proc debugLog(messageType: MessageType, message: string) =
-  let debugMessage =
-    case messageType:
-      of read:
-        "lsp: Read messages: \n" & message & '\n'
-      of write:
-        "lsp: Write messages: \n" & message & '\n'
-
-  debug debugMessage
-  addMessageLog debugMessage
-
-proc readFrame(s: AsyncStreamReader): ReadFrameResult =
+proc debugLog(messageType: MessageType, message: string) {.raises: [].} =
+  try:
+    let debugMessage =
+      case messageType:
+        of read:
+          "lsp: Read messages: \n" & message & '\n'
+        of write:
+          "lsp: Write messages: \n" & message & '\n'
+
+    debug debugMessage
+    addMessageLog debugMessage
+  except:
+    discard
+
+proc readFrame(s: AsyncStreamReader): Future[ReadFrameResult] {.async.} =
   ## Read text from the stream and return json node.
 
   while true:
     let buf =
       try:
-        let f = s.readLine
-        if waitFor f.withTimeout(Timeout):
+        let f = s.readLine(sep="\r\n\r\n")
+        if await f.withTimeout(Timeout):
           f.value
         else:
           return ReadFrameResult.err fmt"readLine: timeout"
@@ -119,8 +124,8 @@ proc readFrame(s: AsyncStreamReader): ReadFrameResult =
     if contentLen != -1:
       let buf=
         try:
-          let f = s.read(contentLen + 1)
-          if waitFor f.withTimeout(Timeout):
+          let f = s.read(contentLen)
+          if await f.withTimeout(Timeout):
             string.fromBytes(f.value)
           else:
             return ReadFrameResult.err fmt"readStr failed"
@@ -131,10 +136,10 @@ proc readFrame(s: AsyncStreamReader): ReadFrameResult =
     else:
       return ReadFrameResult.err "Missing Content-Length header"
 
-proc read*(s: AsyncStreamReader): JsonRpcResponseResult =
+proc read*(s: OutputStream): Future[JsonRpcResponseResult] {.async.} =
   ## Return a json-rpc response from the stream.
 
-  let r = s.readFrame
+  let r = await s.stream.readFrame
   if r.isErr:
     return JsonRpcResponseResult.err r.error
 
@@ -150,8 +155,8 @@ proc read*(s: AsyncStreamReader): JsonRpcResponseResult =
     return JsonRpcResponseResult.err fmt"Invalid jsonrpc: {$res}"
 
 proc send(
-  s: AsyncStreamWriter,
-  frame: string): Result[(), string] =
+  s: InputStream,
+  frame: string): Future[Result[(), string]] {.async.} =
     ## Write json-rpc message to the stream.
 
     let req = "Content-Length: " & $frame.len & "\r\n\r\n" & frame
@@ -159,7 +164,7 @@ proc send(
     debugLog(MessageType.write, req)
 
     try:
-      if not waitFor s.write(req).withTimeout(Timeout):
+      if not await s.stream.write(req).withTimeout(Timeout):
         return Result[(), string].err "write: Timeout"
     except CatchableError as e:
       return Result[(), string].err e.msg
@@ -174,12 +179,12 @@ template newRequest*(id: int, methodName: string, params: JsonNode): JsonNode =
     "params": params
   }
 
-proc sendRequest*(stream: AsyncStreamWriter, req: JsonNode): JsonRpcSendResult =
+proc sendRequest*(s: InputStream, req: JsonNode): Future[JsonRpcSendResult] {.async.} =
   ## Send a request and return a response.
 
-  var s = newStringOfCap(1024)
-  s.toUgly(req)
-  let err = stream.send(s)
+  var str = newStringOfCap(1024)
+  str.toUgly(req)
+  let err = await s.send(str)
   if err.isErr:
     return JsonRpcSendResult.err err.error
 
@@ -192,11 +197,11 @@ template newNotify*(methodName: string, params: JsonNode): JsonNode =
     "params": params
   }
 
-proc sendNotify*(stream: AsyncStreamWriter, notify: JsonNode): Result[(), string] =
+proc sendNotify*(s: InputStream, notify: JsonNode): Future[Result[(), string]] {.async.} =
   ## Send a notification.
   ## No response to the notification. Also, no `id` is required in the
   ## request.
 
-  var s = newStringOfCap(1024)
-  s.toUgly(notify)
-  return stream.send(s)
+  var str = newStringOfCap(1024)
+  str.toUgly(notify)
+  return await s.send(str)
diff --git a/src/moepkg/mainloop.nim b/src/moepkg/mainloop.nim
index 2f321a5f6..32769135e 100644
--- a/src/moepkg/mainloop.nim
+++ b/src/moepkg/mainloop.nim
@@ -905,7 +905,7 @@ proc sendLspRequests(status: var EditorStatus) =
     currentBufStatus.documentHighlightInfo = DocumentHighlightInfo(
       position: currentMainWindowNode.bufferPosition)
 
-    let err = lspClient.textDocumentDocumentHighlight(
+    let err = waitFor lspClient.textDocumentDocumentHighlight(
       currentBufStatus.id,
       $currentBufStatus.absolutePath,
       currentMainWindowNode.bufferPosition)
diff --git a/src/moepkg/messagelog.nim b/src/moepkg/messagelog.nim
index 32d7b8547..26b85faef 100644
--- a/src/moepkg/messagelog.nim
+++ b/src/moepkg/messagelog.nim
@@ -20,7 +20,7 @@
 import unicodeext
 
 ## Log messages displayed on the command line.
-var messageLog: seq[Runes]
+var messageLog {.threadvar.}: seq[Runes]
 
 proc addMessageLog*(message: Runes) =
   ## Add messages to `logger.messageLog`.
diff --git a/src/moepkg/normalmode.nim b/src/moepkg/normalmode.nim
index 072578a98..63fb84055 100644
--- a/src/moepkg/normalmode.nim
+++ b/src/moepkg/normalmode.nim
@@ -584,7 +584,7 @@ proc requestGotoDeclaration(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentDeclaration(
+  let r = waitFor lspClient.textDocumentDeclaration(
     currentBufStatus.id,
     $currentBufStatus.absolutePath,
     currentMainWindowNode.bufferPosition)
@@ -596,7 +596,7 @@ proc requestGotoDefinition(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentDefinition(
+  let r = waitFor lspClient.textDocumentDefinition(
     currentBufStatus.id,
     $currentBufStatus.absolutePath,
     currentMainWindowNode.bufferPosition)
@@ -608,7 +608,7 @@ proc requestGotoTypeDefinition(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentTypeDefinition(
+  let r = waitFor lspClient.textDocumentTypeDefinition(
     currentBufStatus.id,
     $currentBufStatus.absolutePath,
     currentMainWindowNode.bufferPosition)
@@ -620,7 +620,7 @@ proc requestGotoImplementation(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentImplementation(
+  let r = waitFor lspClient.textDocumentImplementation(
     currentBufStatus.id,
     $currentBufStatus.absolutePath,
     currentMainWindowNode.bufferPosition)
@@ -632,7 +632,7 @@ proc requestFindReferences(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentReferences(
+  let r = waitFor lspClient.textDocumentReferences(
     currentBufStatus.id,
     $currentBufStatus.path.absolutePath,
     currentMainWindowNode.bufferPosition)
@@ -644,7 +644,7 @@ proc requestPrepareCallHierarchy(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentPrepareCallHierarchy(
+  let r = waitFor lspClient.textDocumentPrepareCallHierarchy(
     currentBufStatus.id,
     $currentBufStatus.path.absolutePath,
     currentMainWindowNode.bufferPosition)
@@ -656,7 +656,7 @@ proc requestDocumentLink(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentDocumentLink(
+  let r = waitFor lspClient.textDocumentDocumentLink(
     currentBufStatus.id,
     $currentBufStatus.path.absolutePath)
   if r.isErr:
@@ -669,7 +669,7 @@ proc requestDocumentSymbol(status: var EditorStatus) =
          "client is not ready")
        return
 
-  let r = lspClient.textDocumentDocumentSymbol(
+  let r = waitFor lspClient.textDocumentDocumentSymbol(
     currentBufStatus.id,
     $currentBufStatus.absolutePath)
   if r.isErr:
@@ -764,7 +764,7 @@ proc requestRename(status: var EditorStatus) =
   if status.commandLine.getKeys(Prompt):
     let newName = $status.commandLine.buffer
 
-    let r = lspClient.textDocumentRename(
+    let r = waitFor lspClient.textDocumentRename(
       currentBufStatus.id,
       $currentBufStatus.path.absolutePath,
       currentMainWindowNode.bufferPosition,
@@ -779,7 +779,7 @@ proc requestSelectionRange(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = lspClient.textDocumentSelectionRange(
+  let r = waitFor lspClient.textDocumentSelectionRange(
     currentBufStatus.id,
     $currentBufStatus.path.absolutePath,
     @[currentMainWindowNode.bufferPosition])
@@ -1351,7 +1351,7 @@ proc requestHover(status: var EditorStatus) =
     debug "lsp client is not ready"
     return
 
-  let r = status.lspClients[currentBufStatus.langId].textDocumentHover(
+  let r = waitFor lspClient.textDocumentHover(
     currentBufStatus.id,
     $currentBufStatus.path.absolutePath,
     currentMainWindowNode.bufferPosition)
diff --git a/tests/tlspclient.nim b/tests/tlspclient.nim
index 40d5bc3c4..ef6fcd020 100644
--- a/tests/tlspclient.nim
+++ b/tests/tlspclient.nim
@@ -130,7 +130,7 @@ suite "lsp: restart":
         beforePid = client.serverProcessId
         beforeLogLen = client.log.len
 
-      client.serverProcess.kill
+      discard client.kill
 
       check client.restart.isOk