feat(coding-agent): add composable editor factory access

closes #3935

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- Added `ctx.ui.getEditorComponent()` so extensions can wrap the currently configured custom editor factory ([#3935](https://github.com/badlogic/pi-mono/issues/3935)).
+
 ### Fixed
 
 - Fixed idle follow-up submission to clear the editor like normal message submission ([#3926](https://github.com/badlogic/pi-mono/issues/3926)).

packages/coding-agent/docs/extensions.md

@@ -2225,6 +2225,10 @@ ctx.ui.setToolsExpanded(wasExpanded);
 
 // Custom editor (vim mode, emacs mode, etc.)
 ctx.ui.setEditorComponent((tui, theme, keybindings) => new VimEditor(tui, theme, keybindings));
+const currentEditor = ctx.ui.getEditorComponent();
+ctx.ui.setEditorComponent((tui, theme, keybindings) =>
+  new WrappedEditor(tui, theme, keybindings, currentEditor?.(tui, theme, keybindings))
+);
 ctx.ui.setEditorComponent(undefined);  // Restore default editor
 
 // Theme management (see themes.md for creating themes)
@@ -2379,8 +2383,18 @@ export default function (pi: ExtensionAPI) {
 - Extend `CustomEditor` (not base `Editor`) to get app keybindings (escape to abort, ctrl+d, model switching)
 - Call `super.handleInput(data)` for keys you don't handle
 - Factory receives `theme` and `keybindings` from the app
+- Use `ctx.ui.getEditorComponent()` before `setEditorComponent()` to wrap the previously configured custom editor
 - Pass `undefined` to restore default: `ctx.ui.setEditorComponent(undefined)`
 
+To compose with another extension that already replaced the editor, capture the previous factory before setting yours:
+
+```typescript
+const previous = ctx.ui.getEditorComponent();
+ctx.ui.setEditorComponent((tui, theme, keybindings) =>
+  new MyEditor(tui, theme, keybindings, { base: previous?.(tui, theme, keybindings) })
+);
+```
+
 See [tui.md](tui.md) Pattern 7 for a complete example with mode indicator.
 
 ### Message Rendering

packages/coding-agent/src/core/extensions/index.ts

@@ -47,6 +47,7 @@ export type {
 	ContextUsage,
 	CustomToolCallEvent,
 	CustomToolResultEvent,
+	EditorFactory,
 	EditToolCallEvent,
 	EditToolResultEvent,
 	ExecOptions,

packages/coding-agent/src/core/extensions/runner.ts

@@ -207,6 +207,7 @@ const noOpUIContext: ExtensionUIContext = {
 	editor: async () => undefined,
 	addAutocompleteProvider: () => {},
 	setEditorComponent: () => {},
+	getEditorComponent: () => undefined,
 	get theme() {
 		return theme;
 	},

packages/coding-agent/src/core/extensions/types.ts

@@ -115,6 +115,7 @@ export interface WorkingIndicatorOptions {
 
 /** Wrap the current autocomplete provider with additional behavior. */
 export type AutocompleteProviderFactory = (current: AutocompleteProvider) => AutocompleteProvider;
+export type EditorFactory = (tui: TUI, theme: EditorTheme, keybindings: KeybindingsManager) => EditorComponent;
 
 /**
  * UI context for extensions to request interactive UI.
@@ -249,9 +250,10 @@ export interface ExtensionUIContext {
 	 * );
 	 * ```
 	 */
-	setEditorComponent(
-		factory: ((tui: TUI, theme: EditorTheme, keybindings: KeybindingsManager) => EditorComponent) | undefined,
-	): void;
+	setEditorComponent(factory: EditorFactory | undefined): void;
+
+	/** Get the currently configured custom editor factory, or undefined when using the default editor. */
+	getEditorComponent(): EditorFactory | undefined;
 
 	/** Get the current theme for styling. */
 	readonly theme: Theme;

packages/coding-agent/src/modes/interactive/interactive-mode.ts

@@ -20,7 +20,6 @@ import type {
 	AutocompleteItem,
 	AutocompleteProvider,
 	EditorComponent,
-	EditorTheme,
 	Keybinding,
 	KeyId,
 	MarkdownTheme,
@@ -60,6 +59,7 @@ import { type AgentSession, type AgentSessionEvent, parseSkillBlock } from "../.
 import { type AgentSessionRuntime, SessionImportFileNotFoundError } from "../../core/agent-session-runtime.js";
 import type {
 	AutocompleteProviderFactory,
+	EditorFactory,
 	ExtensionCommandContext,
 	ExtensionContext,
 	ExtensionRunner,
@@ -251,6 +251,7 @@ export class InteractiveMode {
 	private statusContainer: Container;
 	private defaultEditor: CustomEditor;
 	private editor: EditorComponent;
+	private editorComponentFactory: EditorFactory | undefined;
 	private autocompleteProvider: AutocompleteProvider | undefined;
 	private autocompleteProviderWrappers: AutocompleteProviderFactory[] = [];
 	private fdPath: string | undefined;
@@ -1985,6 +1986,7 @@ export class InteractiveMode {
 				this.setupAutocompleteProvider();
 			},
 			setEditorComponent: (factory) => this.setCustomEditorComponent(factory),
+			getEditorComponent: () => this.editorComponentFactory,
 			get theme() {
 				return theme;
 			},
@@ -2182,9 +2184,9 @@ export class InteractiveMode {
 	 * Set a custom editor component from an extension.
 	 * Pass undefined to restore the default editor.
 	 */
-	private setCustomEditorComponent(
-		factory: ((tui: TUI, theme: EditorTheme, keybindings: KeybindingsManager) => EditorComponent) | undefined,
-	): void {
+	private setCustomEditorComponent(factory: EditorFactory | undefined): void {
+		this.editorComponentFactory = factory;
+
 		// Save text from current editor before switching
 		const currentText = this.editor.getText();
 

packages/coding-agent/src/modes/rpc/rpc-mode.ts

@@ -271,6 +271,11 @@ export async function runRpcMode(runtimeHost: AgentSessionRuntime): Promise<neve
 			// Custom editor components not supported in RPC mode
 		},
 
+		getEditorComponent() {
+			// Custom editor components not supported in RPC mode
+			return undefined;
+		},
+
 		get theme() {
 			return theme;
 		},