eclipse-theia · ndoschek · Oct 20, 2025 · Oct 9, 2025
diff --git a/packages/ai-chat/src/browser/change-set-file-element.ts b/packages/ai-chat/src/browser/change-set-file-element.ts
@@ -15,7 +15,7 @@
 // *****************************************************************************
 
 import { ConfigurableInMemoryResources, ConfigurableMutableReferenceResource } from '@theia/ai-core';
-import { CancellationToken, DisposableCollection, Emitter, URI } from '@theia/core';
+import { CancellationToken, DisposableCollection, Emitter, nls, URI } from '@theia/core';
 import { ConfirmDialog } from '@theia/core/lib/browser';
 import { Replacement } from '@theia/core/lib/common/content-replacer';
 import { inject, injectable, postConstruct } from '@theia/core/shared/inversify';
@@ -448,12 +448,18 @@ export class ChangeSetFileElement implements ChangeSetElement {
         }
     }
 
-    async confirm(verb: string): Promise<boolean> {
+    async confirm(verb: 'Apply' | 'Revert'): Promise<boolean> {
         if (this._state !== 'stale') { return true; }
         await this.openChange();
         const answer = await new ConfirmDialog({
-            title: `${verb} suggestion.`,
-            msg: `The file ${this.uri.path.toString()} has changed since this suggestion was created. Are you certain you wish to ${verb.toLowerCase()} the change?`
+            title: verb === 'Apply'
+                ? nls.localize('theia/ai/chat/applySuggestion', 'Apply suggestion')
+                : nls.localize('theia/ai/chat/revertSuggestion', 'Revert suggestion'),
+            msg: verb === 'Apply'
+                ? nls.localize('theia/ai/chat/confirmApplySuggestion',
+                    'The file {0} has changed since this suggestion was created. Are you certain you wish to apply the change?', this.uri.path.toString())
+                : nls.localize('theia/ai/chat/confirmRevertSuggestion',
+                    'The file {0} has changed since this suggestion was created. Are you certain you wish to revert the change?', this.uri.path.toString())
         }).open(true);
         return !!answer;
     }

diff --git a/packages/ai-chat/src/browser/change-set-file-service.ts b/packages/ai-chat/src/browser/change-set-file-service.ts
@@ -14,7 +14,7 @@
 // SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0
 // *****************************************************************************
 
-import { ILogger, URI } from '@theia/core';
+import { ILogger, nls, URI } from '@theia/core';
 import { ApplicationShell, DiffUris, LabelProvider, NavigatableWidget, OpenerService, open } from '@theia/core/lib/browser';
 import { inject, injectable } from '@theia/core/shared/inversify';
 import { EditorManager } from '@theia/editor/lib/browser';
@@ -79,7 +79,7 @@ export class ChangeSetFileService {
         if (wsUri) {
             const wsRelative = wsUri.relative(uri);
             if (wsRelative?.hasDir) {
-                return `${wsRelative.dir.toString()}`;
+                return wsRelative.dir.toString();
             }
             return '';
         }
@@ -104,7 +104,7 @@ export class ChangeSetFileService {
 
     protected getDiffUri(originalUri: URI, suggestedUri: URI): URI {
         return DiffUris.encode(originalUri, suggestedUri,
-            `AI Changes: ${this.labelProvider.getName(originalUri)}`,
+            nls.localize('theia/ai/chat/changeSetFileDiffUriLabel', 'AI Changes: {0}', this.labelProvider.getName(originalUri)),
         );
     }
 

diff --git a/packages/ai-chat/src/browser/file-chat-variable-contribution.ts b/packages/ai-chat/src/browser/file-chat-variable-contribution.ts
@@ -17,7 +17,7 @@
 import { AIVariableContext, AIVariableResolutionRequest, PromptText } from '@theia/ai-core';
 import { AIVariableCompletionContext, AIVariableDropResult, FrontendVariableContribution, FrontendVariableService } from '@theia/ai-core/lib/browser';
 import { FILE_VARIABLE } from '@theia/ai-core/lib/browser/file-variable-contribution';
-import { CancellationToken, ILogger, QuickInputService, URI } from '@theia/core';
+import { CancellationToken, ILogger, nls, QuickInputService, URI } from '@theia/core';
 import { inject, injectable } from '@theia/core/shared/inversify';
 import * as monaco from '@theia/monaco-editor-core';
 import { FileQuickPickItem, QuickFileSelectService } from '@theia/file-search/lib/browser/quick-file-select-service';
@@ -76,7 +76,7 @@ export class FileChatVariableContribution implements FrontendVariableContributio
 
     protected async imageArgumentPicker(): Promise<string | undefined> {
         const quickPick = this.quickInputService.createQuickPick();
-        quickPick.title = 'Select an image file';
+        quickPick.title = nls.localize('theia/ai/chat/selectImageFile', 'Select an image file');
 
         // Get all files and filter only image files
         const allPicks = await this.quickFileSelectService.getPicks();

diff --git a/packages/ai-chat/src/browser/image-context-variable-contribution.ts b/packages/ai-chat/src/browser/image-context-variable-contribution.ts
@@ -148,6 +148,6 @@ export class ImageContextVariableContribution implements AIVariableContribution,
 
     getDetails(element: ImageContextVariableRequest): string | undefined {
         const path = ImageContextVariable.parseArg(element.arg).wsRelativePath;
-        return path ? this.labelProvider.getDetails(new URI(path)) : '[pasted]';
+        return path ? this.labelProvider.getDetails(new URI(path)) : undefined;
     }
 }
diff --git a/packages/ai-chat/src/browser/task-context-service.ts b/packages/ai-chat/src/browser/task-context-service.ts
@@ -15,7 +15,7 @@
 // *****************************************************************************
 
 import { inject, injectable } from '@theia/core/shared/inversify';
-import { MaybePromise, ProgressService, URI, generateUuid, Event, EOL } from '@theia/core';
+import { MaybePromise, ProgressService, URI, generateUuid, Event, EOL, nls } from '@theia/core';
 import { ChatAgent, ChatAgentLocation, ChatService, ChatSession, MutableChatModel, MutableChatRequestModel, ParsedChatRequestTextPart } from '../common';
 import { PreferenceService } from '@theia/core/lib/common';
 import { ChatSessionSummaryAgent } from '../common/chat-session-summary-agent';
@@ -90,7 +90,10 @@ export class TaskContextService {
         if (existing && !override) { return existing.id; }
         const summaryId = generateUuid();
         const summaryDeferred = new Deferred<Summary>();
-        const progress = await this.progressService.showProgress({ text: `Summarize: ${session.title || session.id}`, options: { location: 'ai-chat' } });
+        const progress = await this.progressService.showProgress({
+            text: nls.localize('theia/ai/chat/taskContextService/summarizeProgressMessage', 'Summarize: {0}', session.title || session.id),
+            options: { location: 'ai-chat' }
+        });
         this.pendingSummaries.set(session.id, summaryDeferred.promise);
         try {
             const prompt = await this.getSystemPrompt(session, promptId);
@@ -127,7 +130,10 @@ export class TaskContextService {
             return this.summarize(session, promptId, agent, override);
         }
 
-        const progress = await this.progressService.showProgress({ text: `Updating: ${session.title || session.id}`, options: { location: 'ai-chat' } });
+        const progress = await this.progressService.showProgress({
+            text: nls.localize('theia/ai/chat/taskContextService/updatingProgressMessage', 'Updating: {0}', session.title || session.id),
+            options: { location: 'ai-chat' }
+        });
         try {
             const prompt = await this.getSystemPrompt(session, promptId);
             if (!prompt) {

diff --git a/packages/ai-chat/src/browser/task-context-variable.ts b/packages/ai-chat/src/browser/task-context-variable.ts
@@ -15,14 +15,19 @@
 // *****************************************************************************
 
 import { AIVariable } from '@theia/ai-core';
+import { nls } from '@theia/core';
 import { codiconArray } from '@theia/core/lib/browser';
 
 export const TASK_CONTEXT_VARIABLE: AIVariable = {
     id: 'taskContext',
-    description: 'Provides context information for a task, e.g. the plan for completing a task or a summary of a previous sessions',
+    description: nls.localize('theia/chat/taskContextVariable/description',
+        'Provides context information for a task, e.g. the plan for completing a task or a summary of a previous sessions'),
     name: 'taskContext',
-    label: 'Task Context',
+    label: nls.localize('theia/chat/taskContextVariable/label', 'Task Context'),
     iconClasses: codiconArray('clippy'),
     isContextVariable: true,
-    args: [{ name: 'context-id', description: 'The ID of the task context to retrieve, or a chat session to summarize.' }]
+    args: [{
+        name: 'context-id',
+        description: nls.localize('theia/chat/taskContextVariable/args/contextId/description', 'The ID of the task context to retrieve, or a chat session to summarize.')
+    }]
 };
diff --git a/packages/ai-chat/src/common/change-set.ts b/packages/ai-chat/src/common/change-set.ts
@@ -14,7 +14,7 @@
 // SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0
 // *****************************************************************************
 
-import { ArrayUtils, Disposable, Emitter, Event, URI } from '@theia/core';
+import { ArrayUtils, Disposable, Emitter, Event, nls, URI } from '@theia/core';
 
 export interface ChangeSetElement {
     readonly uri: URI;
@@ -95,7 +95,7 @@ export class ChangeSetImpl implements ChangeSet {
 
     protected hasBeenSet = false;
     protected _elements = new Map<string, ChangeSetElement | undefined>();
-    protected _title = 'Suggested Changes';
+    protected _title = nls.localize('theia/ai/chat/changeSetDefaultTitle', 'Suggested Changes');
     get title(): string {
         return this._title;
     }

diff --git a/packages/ai-chat/src/common/chat-agents-variable-contribution.ts b/packages/ai-chat/src/common/chat-agents-variable-contribution.ts
@@ -13,7 +13,7 @@
 //
 // SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0
 // *****************************************************************************
-import { MaybePromise } from '@theia/core';
+import { MaybePromise, nls } from '@theia/core';
 import { inject, injectable } from '@theia/core/shared/inversify';
 import {
     AIVariable,
@@ -29,7 +29,7 @@ import { ChatAgentService } from './chat-agent-service';
 export const CHAT_AGENTS_VARIABLE: AIVariable = {
     id: 'chatAgents',
     name: 'chatAgents',
-    description: 'Returns the list of chat agents available in the system'
+    description: nls.localize('theia/ai/chat/chatAgentsVariable/description', 'Returns the list of chat agents available in the system')
 };
 
 export interface ChatAgentDescriptor {

diff --git a/packages/ai-chat/src/common/chat-agents.ts b/packages/ai-chat/src/common/chat-agents.ts
@@ -49,7 +49,7 @@ import {
     LanguageModelRegistry,
     LanguageModelStreamResponsePart
 } from '@theia/ai-core/lib/common';
-import { ContributionProvider, ILogger, isArray } from '@theia/core';
+import { ContributionProvider, ILogger, isArray, nls } from '@theia/core';
 import { inject, injectable, named, postConstruct } from '@theia/core/shared/inversify';
 import { ChatAgentService } from './chat-agent-service';
 import {
@@ -155,7 +155,7 @@ export abstract class AbstractChatAgent implements ChatAgent {
     readonly abstract languageModelRequirements: LanguageModelRequirement[];
     iconClass: string = 'codicon codicon-copilot';
     locations: ChatAgentLocation[] = ChatAgentLocation.ALL;
-    tags: string[] = ['Chat'];
+    tags: string[] = [nls.localizeByDefault('Chat')];
     description: string = '';
     variables: string[] = [];
     prompts: PromptVariantSet[] = [];
@@ -180,7 +180,7 @@ export abstract class AbstractChatAgent implements ChatAgent {
         try {
             const languageModel = await this.getLanguageModel(this.defaultLanguageModelPurpose);
             if (!languageModel) {
-                throw new Error('Couldn\'t find a matching language model. Please check your setup!');
+                throw new Error(nls.localize('theia/ai/chat/couldNotFindMatchingLM', 'Couldn\'t find a matching language model. Please check your setup!'));
             }
             const systemMessageDescription = await this.getSystemMessageDescription({ model: request.session, request } satisfies ChatSessionContext);
             const messages = await this.getMessages(request.session);
@@ -237,7 +237,7 @@ export abstract class AbstractChatAgent implements ChatAgent {
     protected async selectLanguageModel(selector: LanguageModelRequirement): Promise<LanguageModel> {
         const languageModel = await this.languageModelRegistry.selectLanguageModel({ agent: this.id, ...selector });
         if (!languageModel) {
-            throw new Error(`Couldn\'t find a ready language model for agent ${this.id}. Please check your setup!`);
+            throw new Error(nls.localize('theia/ai/chat/couldNotFindReadyLMforAgent', 'Couldn\'t find a ready language model for agent {0}. Please check your setup!', this.id));
         }
         return languageModel;
     }

diff --git a/packages/ai-chat/src/common/chat-session-naming-service.ts b/packages/ai-chat/src/common/chat-session-naming-service.ts
@@ -26,7 +26,7 @@ import {
 } from '@theia/ai-core';
 import { inject, injectable } from '@theia/core/shared/inversify';
 import { ChatSession } from './chat-service';
-import { generateUuid } from '@theia/core';
+import { generateUuid, nls } from '@theia/core';
 
 import { CHAT_SESSION_NAMING_PROMPT } from './chat-session-naming-prompt-template';
 
@@ -47,16 +47,24 @@ export class ChatSessionNamingAgent implements Agent {
     static ID = 'Chat Session Naming';
     id = ChatSessionNamingAgent.ID;
     name = ChatSessionNamingAgent.ID;
-    description = 'Agent for generating chat session names';
+    description = nls.localize('theia/ai/chat/chatSessionNamingAgent/description', 'Agent for generating chat session names');
     variables = [];
     prompts = [CHAT_SESSION_NAMING_PROMPT];
     languageModelRequirements: LanguageModelRequirement[] = [{
         purpose: 'chat-session-naming',
         identifier: 'default/summarize',
     }];
     agentSpecificVariables = [
-        { name: 'conversation', usedInPrompt: true, description: 'The content of the chat conversation.' },
-        { name: 'listOfSessionNames', usedInPrompt: true, description: 'The list of existing session names.' }
+        {
+            name: 'conversation',
+            usedInPrompt: true,
+            description: nls.localize('theia/ai/chat/chatSessionNamingAgent/vars/conversation/description', 'The content of the chat conversation.')
+        },
+        {
+            name: 'listOfSessionNames',
+            usedInPrompt: true,
+            description: nls.localize('theia/ai/chat/chatSessionNamingAgent/vars/listOfSessionNames/description', 'The list of existing session names.')
+        }
     ];
     functions = [];
 

diff --git a/packages/ai-chat/src/common/chat-session-summary-agent-prompt.ts b/packages/ai-chat/src/common/chat-session-summary-agent-prompt.ts
@@ -24,7 +24,7 @@ export const CHAT_SESSION_SUMMARY_PROMPT = {
             'The summary will primarily be used by other AI agents, so tailor your response for use by AI agents. ' +
             'Also consider the system message. ' +
             'Make sure you include all necessary context information and use unique references (such as URIs, file paths, etc.). ' +
-            'If the conversation was about a task, describe the state of the task, i.e.what has been completed and what is open. ' +
+            'If the conversation was about a task, describe the state of the task, i.e. what has been completed and what is open. ' +
             'If a changeset is open in the session, describe the state of the suggested changes. ' +
             `\n\n{{${CHANGE_SET_SUMMARY_VARIABLE_ID}}}`,
     }

diff --git a/packages/ai-chat/src/common/chat-session-summary-agent.ts b/packages/ai-chat/src/common/chat-session-summary-agent.ts
@@ -21,13 +21,14 @@ import {
 import { injectable } from '@theia/core/shared/inversify';
 import { AbstractStreamParsingChatAgent, ChatAgent } from './chat-agents';
 import { CHAT_SESSION_SUMMARY_PROMPT } from './chat-session-summary-agent-prompt';
+import { nls } from '@theia/core';
 
 @injectable()
 export class ChatSessionSummaryAgent extends AbstractStreamParsingChatAgent implements ChatAgent {
     static ID = 'chat-session-summary-agent';
     id = ChatSessionSummaryAgent.ID;
     name = 'Chat Session Summary';
-    override description = 'Agent for generating chat session summaries.';
+    override description = nls.localize('theia/ai/chat/chatSessionSummaryAgent/description', 'Agent for generating chat session summaries.');
     override prompts: PromptVariantSet[] = [CHAT_SESSION_SUMMARY_PROMPT];
     protected readonly defaultLanguageModelPurpose = 'chat-session-summary';
     languageModelRequirements: LanguageModelRequirement[] = [{

diff --git a/packages/ai-chat/src/common/chat-tool-preferences.ts b/packages/ai-chat/src/common/chat-tool-preferences.ts
@@ -70,7 +70,7 @@ export const chatToolPreferences: PreferenceSchema = {
             },
             default: {},
             description: nls.localize('theia/ai/chat/toolConfirmation/description',
-                'Configure confirmation behavior for different tools. Key is the tool ID, value is the confirmation mode.' +
+                'Configure confirmation behavior for different tools. Key is the tool ID, value is the confirmation mode. ' +
                 'Use "*" as the key to set a global default for all tools.'),
             title: AI_CORE_PREFERENCES_TITLE,
         }
@@ -80,4 +80,3 @@ export const chatToolPreferences: PreferenceSchema = {
 export interface ChatToolConfiguration {
     [TOOL_CONFIRMATION_PREFERENCE]: { [toolId: string]: ToolConfirmationMode };
 }
-
diff --git a/packages/ai-chat/src/common/image-context-variable.ts b/packages/ai-chat/src/common/image-context-variable.ts
@@ -19,19 +19,34 @@ import {
     AIVariableResolutionRequest,
     ResolvedAIContextVariable
 } from '@theia/ai-core';
+import { nls } from '@theia/core';
 
 export const IMAGE_CONTEXT_VARIABLE: AIVariable = {
     id: 'imageContext',
-    description: 'Provides context information for an image',
+    description: nls.localize('theia/ai/chat/imageContextVariable/description', 'Provides context information for an image'),
     name: 'imageContext',
-    label: 'Image File',
+    label: nls.localize('theia/ai/chat/imageContextVariable/label', 'Image File'),
     iconClasses: ['codicon', 'codicon-file-media'],
     isContextVariable: true,
     args: [
-        { name: 'name', description: 'The name of the image file if available.', isOptional: true },
-        { name: 'wsRelativePath', description: 'The workspace-relative path of the image file if available.', isOptional: true },
-        { name: 'data', description: 'The image data in base64.' },
-        { name: 'mimeType', description: 'The mimetype of the image.' }
+        {
+            name: 'name',
+            description: nls.localize('theia/ai/chat/imageContextVariable/args/name/description', 'The name of the image file if available.'),
+            isOptional: true
+        },
+        {
+            name: 'wsRelativePath',
+            description: nls.localize('theia/ai/chat/imageContextVariable/args/wsRelativePath/description', 'The workspace-relative path of the image file if available.'),
+            isOptional: true
+        },
+        {
+            name: 'data',
+            description: nls.localize('theia/ai/chat/imageContextVariable/args/data/description', 'The image data in base64.')
+        },
+        {
+            name: 'mimeType',
+            description: nls.localize('theia/ai/chat/imageContextVariable/args/mimeType/description', 'The mimetype of the image.')
+        }
     ]
 };