diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 4b8e810b..293e127e 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -4,9 +4,11 @@
 
 ### Added
 
+- ExtensionAPI: `setModel()`, `getThinkingLevel()`, `setThinkingLevel()` methods for extensions to change model and thinking level at runtime ([#509](https://github.com/badlogic/pi-mono/issues/509))
 - Exported truncation utilities for custom tools: `truncateHead`, `truncateTail`, `truncateLine`, `formatSize`, `DEFAULT_MAX_BYTES`, `DEFAULT_MAX_LINES`, `TruncationOptions`, `TruncationResult`
 - New example `truncated-tool.ts` demonstrating proper output truncation with custom rendering for extensions
 - Documentation for output truncation best practices in `docs/extensions.md`
+- Exported all UI components for extensions: `ArminComponent`, `AssistantMessageComponent`, `BashExecutionComponent`, `BorderedLoader`, `BranchSummaryMessageComponent`, `CompactionSummaryMessageComponent`, `CustomEditor`, `CustomMessageComponent`, `DynamicBorder`, `ExtensionEditorComponent`, `ExtensionInputComponent`, `ExtensionSelectorComponent`, `FooterComponent`, `LoginDialogComponent`, `ModelSelectorComponent`, `OAuthSelectorComponent`, `SessionSelectorComponent`, `SettingsSelectorComponent`, `ShowImagesSelectorComponent`, `ThemeSelectorComponent`, `ThinkingSelectorComponent`, `ToolExecutionComponent`, `TreeSelectorComponent`, `UserMessageComponent`, `UserMessageSelectorComponent`, plus utilities `renderDiff`, `truncateToVisualLines`
 
 ## [0.37.4] - 2026-01-06
 
diff --git a/packages/coding-agent/src/index.ts b/packages/coding-agent/src/index.ts
index 97e35e82..daca7825 100644
--- a/packages/coding-agent/src/index.ts
+++ b/packages/coding-agent/src/index.ts
@@ -195,7 +195,40 @@ export {
 // Main entry point
 export { main } from "./main.js";
 // UI components for extensions
-export { BorderedLoader } from "./modes/interactive/components/bordered-loader.js";
+export {
+	ArminComponent,
+	AssistantMessageComponent,
+	BashExecutionComponent,
+	BorderedLoader,
+	BranchSummaryMessageComponent,
+	CompactionSummaryMessageComponent,
+	CustomEditor,
+	CustomMessageComponent,
+	DynamicBorder,
+	ExtensionEditorComponent,
+	ExtensionInputComponent,
+	ExtensionSelectorComponent,
+	FooterComponent,
+	LoginDialogComponent,
+	ModelSelectorComponent,
+	OAuthSelectorComponent,
+	type RenderDiffOptions,
+	renderDiff,
+	SessionSelectorComponent,
+	type SettingsCallbacks,
+	type SettingsConfig,
+	SettingsSelectorComponent,
+	ShowImagesSelectorComponent,
+	ThemeSelectorComponent,
+	ThinkingSelectorComponent,
+	ToolExecutionComponent,
+	type ToolExecutionOptions,
+	TreeSelectorComponent,
+	truncateToVisualLines,
+	UserMessageComponent,
+	UserMessageSelectorComponent,
+	type VisualTruncateResult,
+} from "./modes/interactive/components/index.js";
 // Theme utilities for custom tools and extensions
 export {
 	getMarkdownTheme,
diff --git a/packages/coding-agent/src/modes/interactive/components/index.ts b/packages/coding-agent/src/modes/interactive/components/index.ts
new file mode 100644
index 00000000..9ae7f7c3
--- /dev/null
+++ b/packages/coding-agent/src/modes/interactive/components/index.ts
@@ -0,0 +1,28 @@
+// UI Components for extensions
+export { ArminComponent } from "./armin.js";
+export { AssistantMessageComponent } from "./assistant-message.js";
+export { BashExecutionComponent } from "./bash-execution.js";
+export { BorderedLoader } from "./bordered-loader.js";
+export { BranchSummaryMessageComponent } from "./branch-summary-message.js";
+export { CompactionSummaryMessageComponent } from "./compaction-summary-message.js";
+export { CustomEditor } from "./custom-editor.js";
+export { CustomMessageComponent } from "./custom-message.js";
+export { type RenderDiffOptions, renderDiff } from "./diff.js";
+export { DynamicBorder } from "./dynamic-border.js";
+export { ExtensionEditorComponent } from "./extension-editor.js";
+export { ExtensionInputComponent } from "./extension-input.js";
+export { ExtensionSelectorComponent } from "./extension-selector.js";
+export { FooterComponent } from "./footer.js";
+export { LoginDialogComponent } from "./login-dialog.js";
+export { ModelSelectorComponent } from "./model-selector.js";
+export { OAuthSelectorComponent } from "./oauth-selector.js";
+export { SessionSelectorComponent } from "./session-selector.js";
+export { type SettingsCallbacks, type SettingsConfig, SettingsSelectorComponent } from "./settings-selector.js";
+export { ShowImagesSelectorComponent } from "./show-images-selector.js";
+export { ThemeSelectorComponent } from "./theme-selector.js";
+export { ThinkingSelectorComponent } from "./thinking-selector.js";
+export { ToolExecutionComponent, type ToolExecutionOptions } from "./tool-execution.js";
+export { TreeSelectorComponent } from "./tree-selector.js";
+export { UserMessageComponent } from "./user-message.js";
+export { UserMessageSelectorComponent } from "./user-message-selector.js";
+export { truncateToVisualLines, type VisualTruncateResult } from "./visual-truncate.js";