• [ai] replaced the per-model thinking-mode toggle with a provider-agnostic reasoning selector and ReasoningSettings abstraction; the chosen level can be persisted per agent via the chat capabilities save action #17363
• [ai-anthropic] added display: 'summarized' to adaptive thinking block #17429
• [ai-chat] added taskContextId parameter to delegateToAgent tool #17244
• [ai-chat] dropped incomplete thinking blocks from llm history #17395
• [ai-chat] fixed agent label casing in delegation renderer #17234
• [ai-chat-ui] added token usage indicator to chat view #17028
• [ai-chat-ui] fixed inverted expand/collapse in capabilities tree during search #17248
• [ai-chat-ui] fixed issue with preserving user-selected mode during agent delegation #17307
• [ai-chat-ui] integrated tool confirmation system into DelegationToolRenderer #17293
• [ai-chat-ui] show tool confirmation in collapsed delegation summary #16926
• [ai-chat-ui] used partial JSON extraction to prevent tool call label flicker #17306
• [ai-chat-ui] warned when chat session token usage crosses a threshold #17387
• [ai-core] prompt templates do not get modified only by opening them #17277
• [ai-core] provided ready promise for SkillService #17317
• [ai-core] updated default AI model versions for Anthropic and OpenAI #17409
• [ai-core] white label theia and theia ide #17265
• [ai-core, ai-chat-ui, ai-chat, ai-claude-code, ai-code-completion, ai-editor, ai-ide] hooked workspace trust into AI features #17364 - contributed on behalf of STMicroelectronics
• [ai-ide] added PR Review Agent with UserInteractionTool #17298
• [ai-ide] fixed chat session canceling completed tasks #17297
• [ai-ide] improved agent mode confirmation UX and sync mode selector #17271
• [ai-ide] improved code prompt and tool descriptions #17197
• [ai-ide] improved todoWrite tool description #17351
• [ai-ide] provided proper icons for agents and fixed icons in ai config #17336
• [ai-ide] readded junior contributions after release #17259
• [ai-ide] removed junior contributions #17418
• [ai-terminal] added description field to shell execution tool #17350
• [ci] used a single rolling next git tag for npm next publishes #17355 - Contributed on behalf of STMicroelectronics
• [collaboration] fixed resolving of auth endpoint paths for server urls with path #16751
• [core] added .tmp.cfg to top-level gitignore #17377
• [core] added errorHandling option to Emitter to control how listener exceptions are handled: 'log' (default), 'propagate' (collect and re-throw), or a custom callback #17332
• [core] API bump and nls update to 1.116.0 #17367 - Contributed on behalf of STMicroelectronics
• [core] belated breaking changes for #17360 #17410
• [core] fixed accessibility issues in the AI chat view #17260
• [core] fixed copy in chat view not working without selection in Electron #17300 - contributed on behalf of STMicroelectronics
• [core] fixed editor context menu filtering and Monaco widget styling #17404 - contributed on behalf of STMicroelectronics
• [core] improved electron window close behavior on windows #17296 - contributed on behalf of STMicroelectronics
• [core] improved start-up performance logging #17368 - contributed on behalf of STMicroelectronics
• [core] limited imports of code in the preload section #17281
• [core] made socketWriteBuffer and reconnectableSocketChannel overridable via DI #17249
• [core] npm upgrade #17282 - contributed on behalf of STMicroelectronics
• [core] onSaveChange: saved on changes of both tab and window focus #17360
• [core] removed stale beta labels from translation files #17314
• [core] showed empty base for both added conflicts in merge editor #17274
• [core] showed Linux env variable hint in API key preferences #17337
• [core] translation update for version 1.71.0 #17433
• [core] unbound all services in the backend in connection-scoped child containers on close. This allows clean-up methods annotated with @preDestroy() to run, releasing resources. Downstream applications should be aware that service instances deliberately shared between connection-scoped containers, and service instances obtained from the root container that are explicitly bound again in the connection-scoped module, will cause such shared services to be destroyed while still in use in other containers. Both of these scenarios are already Inversify anti-patterns, so are not expected to arise in practice. #17384
• [debug] listened to all breakpoint changes #17291
• [dev-container] improved dev container features #17348
• [dev-packages] merged the changes of the release branch #17232
• [doc] added human-in-the-loop PR policy #17283
• [editor] replaced the per-URI editor counter system in EditorManager with random counters #17275
• [electron] fixed skipped smoke test #17335
• [electron] upgraded electron from 39.7.0 to 39.8.7 #17329 - contributed on behalf of STMicroelectronics
• [filesystem] file events avoid creating overlapping watchers (solution 2) #17017
• [github] removed stale CODEOWNERS file #17359
• [monaco] used withServices to detect early Monaco initialization #17361
• [navigator] improved navigator copy/paste handling #17394
• [notebook] fixed space key scrolling instead of typing in cell editors #17284
• [output] added ANSI escape code support to the output view #17285 - Contributed on behalf of STMicroelectronics
• [playwright] fixed the menu shortcut assertion for macos #17371 - Contributed on behalf of STMicroelectronics
• [plugin] disabled listener leak for ext host file watchers #17240
• [plugin] removed private modifier from themeicon declaration & implementation #17325
• [plugin-ext] ensured terminal API object identity and respected grouping mode for plugin-created terminals #17340
• [plugin-ext] supported watching files outside the workspace with createFileSystemWatcher #17239
• [plugin, scm] fixed repository context menus and worktree grouping #17252
• [remote] supported macOS arm64 and rolling next native dependencies #17347 - Contributed on behalf of STMicroelectronics
• [request] used standard fetch API when using node >=18 #17269
• [scm] added SCM history graph with VS Code-compatible plugin API #17263
• [scm] enforced some options for child editors of the merge editor #17303
• [scm] ensured the dirty-diff widget always shows the heading #17421
• [scm] fixed detection of external worktree removal and related stale-state gaps #17389
• [terminal] copy via context menu does not work was fixed #17290 - Contributed on behalf of STMicroelectronics
• [terminal-manager] terminal-manager: fix view not restored on startup #17403
• [test] fixed test extensions and improved test output UX #17341
• [toolbar] updated codicons set and script to updated mapping format #17366
• [workspace] fixed spurious restart dialog from preference change handler #17354

Breaking Changes:

• [ai] removed ThinkingModeSettings and the thinkingMode field from UserRequest / CommonChatSessionSettings in favor of ReasoningSettings { level } and the reasoning field. Provider model descriptions now expose reasoningSupport / reasoningApi. Adopters consuming @theia/ai-core or @theia/ai-chat should migrate to the new request shape #17363
• [core] changed the visibility of ChannelMultiplexer.pendingOpen from protected to private #17332
• [core] Uint8ArrayWriteBuffer's onCommit emitter now propagates exceptions from listeners instead of silently catching them. Code that relied on exceptions being swallowed should add its own error handling #17332
• [editor] replaced the per-URI editor counter system in EditorManager with random counters #17275:
  • Removed protected field editorCounters: Map<string, number>
  • Removed protected method checkCounterForWidget(widget)
  • Removed protected method removeFromCounter(widget)
  • Removed protected method createCounterForUri(uri) (replaced by nextCounter())
  • Removed protected method getOrCreateCounterForUri(uri)
• [plugin-ext] changed the timing of plugin contribution loading: beforeLoadContributions now waits for attached_shell instead of initialized_layout. Overrides of beforeLoadContributions or loadContributions that assume the full layout is already initialized may need to adjust their logic #17278
• [core] disabled Lumino's overflow menu feature in the main menu bar by passing overflowMenuOptions: { isVisible: false } to the MenuBarWidget constructor. The feature was never functional in Theia and could cause a RangeError when toggling menu bar visibility. Adopters who need overflow menu support can override BrowserMainMenuFactory.createMenuBar to construct the DynamicMenuBarWidget with different options #17362
• [core] removed protected methods addBlurListener(widget, saveable) and windowHasFocus(document) from SaveableService. Window-level focus tracking is now handled by the new WindowFocusService #17360