diff --git a/spx-gui/src/apps/xbuilder/widgets/xgo-code-editor/XGoCodeEditor.ce.vue b/spx-gui/src/apps/xbuilder/widgets/xgo-code-editor/XGoCodeEditor.ce.vue
index 81faaea98..57b861022 100644
--- a/spx-gui/src/apps/xbuilder/widgets/xgo-code-editor/XGoCodeEditor.ce.vue
+++ b/spx-gui/src/apps/xbuilder/widgets/xgo-code-editor/XGoCodeEditor.ce.vue
@@ -69,7 +69,7 @@ const {
     await project.load(serialized)
 
     const history = new History(project)
-    const lspClient = new SpxLSPClient(project)
+    const lspClient = new SpxLSPClient(project, { locale: i18n.lang.value })
     lspClient.init()
     const documentBase = new DocumentBase([...Object.values(spxDefinitionsByName), ...spxKeyDefinitions])
 
diff --git a/spx-gui/src/components/editor/spx-code-editor/CodeEditorProvider.vue b/spx-gui/src/components/editor/spx-code-editor/CodeEditorProvider.vue
index c276fcddc..10ff3e4f5 100644
--- a/spx-gui/src/components/editor/spx-code-editor/CodeEditorProvider.vue
+++ b/spx-gui/src/components/editor/spx-code-editor/CodeEditorProvider.vue
@@ -1,12 +1,8 @@
-<template>
-  <CodeEditorInitializer v-if="codeEditorRef != null" :code-editor="codeEditorRef" />
-  <slot></slot>
-</template>
-
 <script setup lang="ts">
 import { shallowRef, watch } from 'vue'
 import { useCopilot } from '@/components/copilot/context'
 import { type Monaco, CodeEditor, DocumentBase, useProvideCodeEditor } from '@/components/xgo-code-editor'
+import { useI18n } from '@/utils/i18n'
 import { useEditorCtx } from '../EditorContextProvider.vue'
 import * as spxDefinitionsByName from './document-base'
 import './document-base/helpers'
@@ -21,15 +17,16 @@ const props = defineProps<{
 
 const copilot = useCopilot()
 const editorCtx = useEditorCtx()
+const i18n = useI18n()
 const codeEditorRef = shallowRef<CodeEditor | null>(null)
 
 watch(
-  () => [props.monaco, editorCtx.state] as const,
-  ([monaco, editorState], _, onCleanup) => {
+  () => [props.monaco, editorCtx.state, i18n.lang.value] as const,
+  ([monaco, editorState, lang], _, onCleanup) => {
     const { project: spxProject, history } = editorState
 
     const project = new SpxCodeEditorProject(spxProject, history)
-    const lspClient = new SpxLSPClient(spxProject)
+    const lspClient = new SpxLSPClient(spxProject, { locale: lang })
     lspClient.onPropertyRenamed(({ target, oldName, newName }) => {
       for (const widget of spxProject.stage.widgets) {
         if (widget.type === 'monitor' && widget.target === target && widget.variableName === oldName) {
@@ -60,3 +57,8 @@ watch(
 
 useProvideCodeEditor(codeEditorRef)
 </script>
+
+<template>
+  <CodeEditorInitializer v-if="codeEditorRef != null" :code-editor="codeEditorRef" />
+  <slot></slot>
+</template>
diff --git a/spx-gui/src/components/editor/spx-code-editor/lsp/spx-lsp-client.ts b/spx-gui/src/components/editor/spx-code-editor/lsp/spx-lsp-client.ts
index 333e82abf..8d3d343e0 100644
--- a/spx-gui/src/components/editor/spx-code-editor/lsp/spx-lsp-client.ts
+++ b/spx-gui/src/components/editor/spx-code-editor/lsp/spx-lsp-client.ts
@@ -4,6 +4,7 @@ import * as Sentry from '@sentry/vue'
 import { Cancelled } from '@/utils/exception'
 import { Disposable, getCleanupSignal, type Disposer } from '@/utils/disposable'
 import Emitter from '@/utils/emitter'
+import type { Lang } from '@/utils/i18n'
 import { timeout, until, untilNotNull } from '@/utils/utils'
 import { extname } from '@/utils/path'
 import { createLSPOperationName, createLSPServerOperationName, type LSPTraceOptions } from '@/utils/tracing'
@@ -23,7 +24,7 @@ import {
   type PropertyRenamedEvent
 } from '@/components/xgo-code-editor'
 import { XGoLanguageClient, type IConnection, ResponseError } from './spxls/client'
-import type { Files as SpxlsFiles, RequestMessage, ResponseMessage, NotificationMessage } from './spxls'
+import type { Files as SpxlsFiles, MessageID, RequestMessage, ResponseMessage, NotificationMessage } from './spxls'
 import { xgoGetInputSlots, xgoGetProperties, xgoRenameResources } from './spxls/commands'
 import { xgoPropertyRenamedNotification } from './spxls/notifications'
 import { isDocumentLinkForResourceReference, parseDocumentLinkForDefinition } from './spxls/methods'
@@ -32,11 +33,23 @@ import type { WorkerHandler } from './worker'
 /** The LSP target name for stage (the "Game" type in spx). */
 const lspStageTarget = 'Game'
 
+const lspClientName = 'XBuilder'
+const lspWorkspaceRootURI = 'file:///'
+const lspWorkspaceRootName = 'workspace'
+
 interface IConnectionWithFiles extends IConnection {
   sendFiles(files: SpxlsFiles): void
   dispose(): void
 }
 
+type SpxLSPClientOptions = {
+  locale?: Lang
+}
+
+function isServerNotInitializedError(error: unknown): error is ResponseError {
+  return error instanceof ResponseError && error.code === lsp.ErrorCodes.ServerNotInitialized
+}
+
 /** Connection between LS client and server when the server runs in a Web Worker. */
 class WorkerConnection implements IConnectionWithFiles {
   private worker: WorkerHandler
@@ -115,7 +128,10 @@ type TelemetryEventParams = TelemetryEventParamsForCall | TelemetryEventParamsFo
 export class SpxLSPClient extends Disposable implements ILSPClient {
   private emitter = new Emitter<LSPClientEvents>()
 
-  constructor(private project: SpxProject) {
+  constructor(
+    private project: SpxProject,
+    private options: SpxLSPClientOptions = {}
+  ) {
     super()
     this.addDisposable(this.emitter)
   }
@@ -155,18 +171,20 @@ export class SpxLSPClient extends Disposable implements ILSPClient {
   }
 
   private lcRef = shallowRef<XGoLanguageClient | null>(null)
-  private activeSpans = new Map<number, Sentry.Span>()
+  private initializePromise: Promise<void> | null = null
+  private activeSpans = new Map<MessageID, Sentry.Span>()
 
   private async prepareRequest() {
-    const [lc] = await Promise.all([
-      untilNotNull(this.lcRef),
-      // Typically requests are triggered earlier than file-loading:
-      // * file-loading: editor-event -> model-update -> file-loading
-      // * request: editor-event -> request
-      // Here we add `timeout(0)` to ensure that file-loading triggered before request really starts.
-      timeout(0).then(() => until(() => !this.isFilesStale.value))
-    ])
-    return lc
+    const lc = await untilNotNull(this.lcRef)
+    const initializePromise = this.initializePromise ?? this.startInitialize(lc)
+    // Typically requests are triggered earlier than file-loading:
+    // * file-loading: editor-event -> model-update -> file-loading
+    // * request: editor-event -> request
+    // Here we add `timeout(0)` to ensure that file-loading triggered before request really starts.
+    await timeout(0)
+    await until(() => !this.isFilesStale.value)
+    await initializePromise
+    return { lc, initializePromise }
   }
 
   init() {
@@ -179,6 +197,8 @@ export class SpxLSPClient extends Disposable implements ILSPClient {
       this.handleTelemetryEventNotification(params)
     })
 
+    this.startInitialize(this.lcRef.value)
+
     // Register handler for property renamed notifications
     this.lcRef.value.onNotification(
       xgoPropertyRenamedNotification.method,
@@ -192,15 +212,85 @@ export class SpxLSPClient extends Disposable implements ILSPClient {
     )
   }
 
+  private createInitializeParams(): lsp.InitializeParams {
+    return {
+      processId: null,
+      clientInfo: {
+        name: lspClientName
+      },
+      locale: this.options.locale,
+      rootUri: lspWorkspaceRootURI,
+      workspaceFolders: [
+        {
+          uri: lspWorkspaceRootURI,
+          name: lspWorkspaceRootName
+        }
+      ],
+      capabilities: {
+        workspace: {
+          workspaceFolders: true
+        },
+        general: {
+          positionEncodings: [lsp.PositionEncodingKind.UTF16]
+        },
+        textDocument: {
+          completion: {
+            completionItem: {
+              snippetSupport: true,
+              documentationFormat: [lsp.MarkupKind.Markdown]
+            }
+          },
+          hover: {
+            contentFormat: [lsp.MarkupKind.Markdown]
+          },
+          rename: {
+            prepareSupport: true
+          },
+          signatureHelp: {
+            contextSupport: true
+          }
+        }
+      }
+    }
+  }
+
+  private async initialize(lc: XGoLanguageClient) {
+    await this.sendRequest<lsp.InitializeResult>(lc, {}, lsp.InitializeRequest.method, this.createInitializeParams())
+    lc.notify(lsp.InitializedNotification.method, {})
+  }
+
+  private startInitialize(lc: XGoLanguageClient) {
+    const initializePromise = this.initialize(lc)
+    this.initializePromise = initializePromise
+    initializePromise.catch(() => {
+      if (this.initializePromise === initializePromise) {
+        this.initializePromise = null
+      }
+    })
+    return initializePromise
+  }
+
+  private reinitialize(lc: XGoLanguageClient, staleInitializePromise: Promise<void>) {
+    const currentInitializePromise = this.initializePromise
+    if (currentInitializePromise != null && currentInitializePromise !== staleInitializePromise) {
+      return currentInitializePromise
+    }
+    return this.startInitialize(lc)
+  }
+
   dispose() {
     this.lcRef.value?.dispose()
     this.connection?.dispose()
     super.dispose()
   }
 
-  /** Do LSP request, with cancellation and tracing. */
-  private async request<T>({ signal, traceOptions }: RequestContext, method: string, params: any): Promise<T> {
-    const lc = await this.prepareRequest()
+  private async sendRequest<T>(
+    lc: XGoLanguageClient,
+    { signal, traceOptions }: RequestContext,
+    method: string,
+    params: any,
+    suppressErrorLog?: (error: unknown) => boolean
+  ): Promise<T> {
     return tracedRequest(
       method,
       async (span: Sentry.Span) => {
@@ -226,7 +316,7 @@ export class SpxLSPClient extends Disposable implements ILSPClient {
             if (e instanceof ResponseError && e.code === lsp.LSPErrorCodes.RequestCancelled) {
               throw new Cancelled(e.message)
             }
-            console.warn(`[LSP] ${method} error:`, e, ', params:', params)
+            if (!suppressErrorLog?.(e)) console.warn(`[LSP] ${method} error:`, e, ', params:', params)
             throw e
           })
           .finally(unlisten)
@@ -235,7 +325,19 @@ export class SpxLSPClient extends Disposable implements ILSPClient {
     )
   }
 
-  private async cancelRequest(id: number) {
+  /** Do LSP request, with cancellation and tracing. */
+  private async request<T>(ctx: RequestContext, method: string, params: any): Promise<T> {
+    const { lc, initializePromise } = await this.prepareRequest()
+    try {
+      return await this.sendRequest<T>(lc, ctx, method, params, isServerNotInitializedError)
+    } catch (e) {
+      if (!isServerNotInitializedError(e)) throw e
+      await this.reinitialize(lc, initializePromise)
+      return this.sendRequest<T>(lc, ctx, method, params)
+    }
+  }
+
+  private async cancelRequest(id: MessageID) {
     const lc = await untilNotNull(this.lcRef)
     // The method `$/cancelRequest` is defined in https://github.com/microsoft/vscode-languageserver-node/blob/4c20197acf4c499345a18e79945e706345cbc50f/protocol/src/common/protocol.%24.ts#L46-L58 ,
     // while not exported by package `vscode-languageserver-protocol`.
diff --git a/spx-gui/src/components/editor/spx-code-editor/lsp/spxls/client.ts b/spx-gui/src/components/editor/spx-code-editor/lsp/spxls/client.ts
index 153965654..676f2156e 100644
--- a/spx-gui/src/components/editor/spx-code-editor/lsp/spxls/client.ts
+++ b/spx-gui/src/components/editor/spx-code-editor/lsp/spxls/client.ts
@@ -1,4 +1,10 @@
-import type { NotificationMessage, RequestMessage, ResponseMessage, ResponseError as ResponseErrorObj } from './index'
+import type {
+  MessageID,
+  NotificationMessage,
+  RequestMessage,
+  ResponseMessage,
+  ResponseError as ResponseErrorObj
+} from './index'
 
 /** Connection between the client and the language server. */
 export interface IConnection {
@@ -8,7 +14,7 @@ export interface IConnection {
 
 export interface OngoingRequest<T> {
   /** Unique ID of the request. */
-  id: number
+  id: MessageID
   /** Returns a promise that resolves with the response of the request. */
   response(): Promise<T>
 }
@@ -19,7 +25,7 @@ export interface OngoingRequest<T> {
 export class XGoLanguageClient {
   private nextRequestId: number = 1
   private pendingRequests = new Map<
-    number,
+    MessageID,
     {
       resolve: (response: any) => void
       reject: (error: any) => void
diff --git a/tools/spxls/go.mod b/tools/spxls/go.mod
index 31f44b7bd..6dc783c13 100644
--- a/tools/spxls/go.mod
+++ b/tools/spxls/go.mod
@@ -26,3 +26,5 @@ require (
 )
 
 replace github.com/goplus/builder/tools/ai => ../ai
+
+replace github.com/goplus/xgolsw => github.com/aofei/fork.goplus.xgolsw v0.0.0-20260701122425-18fd0bb225b8
diff --git a/tools/spxls/go.sum b/tools/spxls/go.sum
index edaab8934..cfed397e9 100644
--- a/tools/spxls/go.sum
+++ b/tools/spxls/go.sum
@@ -1,4 +1,6 @@
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/aofei/fork.goplus.xgolsw v0.0.0-20260701122425-18fd0bb225b8 h1:xvXKSHybkyjRga8bFKuRD4McZooDvskHSSH4rAZC+Oo=
+github.com/aofei/fork.goplus.xgolsw v0.0.0-20260701122425-18fd0bb225b8/go.mod h1:ANgB42yf5ul2VDNMxp6v2yxbcwyNu1wV9IWekAgGSG4=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/goccy/go-yaml v1.19.2 h1:PmFC1S6h8ljIz6gMRBopkjP1TVT7xuwrButHID66PoM=
@@ -15,8 +17,6 @@ github.com/goplus/spx/v2 v2.0.4 h1:4hyCM5XH3DMRjFeoTxCndrqcFZTeCWHkEicyp7wYTSs=
 github.com/goplus/spx/v2 v2.0.4/go.mod h1:mF2kCvUNw97ku2PYHMEwbCENv24b5EwnlXOLiVMRbHM=
 github.com/goplus/xgo v1.7.2 h1:leAinbUiz+oUukKfdYIXyYZlxm/gh6TkEg5/dzvevQk=
 github.com/goplus/xgo v1.7.2/go.mod h1:QR2TaWixDRCYQfv0F7xpZbUPvuclcgg0oUFmcq5nNn0=
-github.com/goplus/xgolsw v0.21.1-0.20260630012157-8eb11678c926 h1:LDYoxTq7UxoZppnHfCPQswH30MevNyoLTX8l0hrKFzo=
-github.com/goplus/xgolsw v0.21.1-0.20260630012157-8eb11678c926/go.mod h1:ANgB42yf5ul2VDNMxp6v2yxbcwyNu1wV9IWekAgGSG4=
 github.com/petermattis/goid v0.0.0-20250721140440-ea1c0173183e h1:D0bJD+4O3G4izvrQUmzCL80zazlN7EwJ0PPDhpJWC/I=
 github.com/petermattis/goid v0.0.0-20250721140440-ea1c0173183e/go.mod h1:pxMtw7cyUw6B2bRH0ZBANSPg+AoSud1I1iyJHI69jH4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
diff --git a/tools/spxls/index.d.ts b/tools/spxls/index.d.ts
index d9d5a920f..b53efcd0b 100644
--- a/tools/spxls/index.d.ts
+++ b/tools/spxls/index.d.ts
@@ -48,6 +48,11 @@ export interface Message {
   jsonrpc: string
 }
 
+/**
+ * A JSON-RPC message identifier.
+ */
+export type MessageID = number | string
+
 /**
  * A request message to describe a request between the client and the server. Every processed request must send a
  * response back to the sender of the request.
@@ -58,7 +63,7 @@ export interface RequestMessage extends Message {
   /**
    * The request id.
    */
-  id: number
+  id: MessageID
 
   /**
    * The method to be invoked.
@@ -82,7 +87,7 @@ export interface ResponseMessage extends Message {
   /**
    * The request id.
    */
-  id: number
+  id: MessageID
 
   /**
    * The result of a request. This member is REQUIRED on success.