fix(coding-agent): persist custom working message across loader recreation

Replace transient pendingWorkingMessage with a persistent workingMessage
field on InteractiveMode, matching the workingIndicatorOptions pattern.
New loaders now use this.workingMessage || this.defaultWorkingMessage
instead of always falling back to the default.

Also add working-message-test.ts extension example.

closes #3566

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed `ctx.ui.setWorkingMessage()` to persist across loader recreation, matching the behavior of `ctx.ui.setWorkingIndicator()` ([#3566](https://github.com/badlogic/pi-mono/issues/3566))
+
 ## [0.69.0] - 2026-04-22
 
 ### New Features

packages/coding-agent/examples/extensions/working-message-test.ts

@@ -0,0 +1,25 @@
+/**
+ * Working Message Persistence Test
+ *
+ * Sets a custom working message and indicator on session start so you can
+ * verify they survive across loader recreations (e.g. between agent turns).
+ *
+ * Usage:
+ *   pi --extension examples/extensions/working-message-test.ts
+ *
+ * Then send a few messages in interactive mode. The working message should
+ * stay "Working... (custom)" with a brown dot indicator every time the
+ * loader appears, not revert to the default gray "Working...".
+ */
+
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+
+const CUSTOM_MESSAGE = "\x1b[38;2;155;86;63mWorking... (custom)\x1b[39m";
+const CUSTOM_INDICATOR = { frames: ["\x1b[38;2;155;86;63m●\x1b[39m"] };
+
+export default function (pi: ExtensionAPI) {
+	pi.on("session_start", async (_event, ctx) => {
+		ctx.ui.setWorkingMessage(CUSTOM_MESSAGE);
+		ctx.ui.setWorkingIndicator(CUSTOM_INDICATOR);
+	});
+}

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

@@ -205,7 +205,7 @@ export class InteractiveMode {
 	private isInitialized = false;
 	private onInputCallback?: (text: string) => void;
 	private loadingAnimation: Loader | undefined = undefined;
-	private pendingWorkingMessage: string | undefined = undefined;
+	private workingMessage: string | undefined = undefined;
 	private workingIndicatorOptions: LoaderIndicatorOptions | undefined = undefined;
 	private readonly defaultWorkingMessage = "Working...";
 	private readonly defaultHiddenThinkingLabel = "Thinking...";
@@ -1724,7 +1724,7 @@ export class InteractiveMode {
 		this.setupAutocompleteProvider();
 		this.defaultEditor.onExtensionShortcut = undefined;
 		this.updateTerminalTitle();
-		this.pendingWorkingMessage = undefined;
+		this.workingMessage = undefined;
 		this.setWorkingIndicator();
 		if (this.loadingAnimation) {
 			this.loadingAnimation.setMessage(`${this.defaultWorkingMessage} (${keyText("app.interrupt")} to interrupt)`);
@@ -1875,6 +1875,7 @@ export class InteractiveMode {
 			onTerminalInput: (handler) => this.addExtensionTerminalInputListener(handler),
 			setStatus: (key, text) => this.setExtensionStatus(key, text),
 			setWorkingMessage: (message) => {
+				this.workingMessage = message;
 				if (this.loadingAnimation) {
 					if (message) {
 						this.loadingAnimation.setMessage(message);
@@ -1883,9 +1884,6 @@ export class InteractiveMode {
 							`${this.defaultWorkingMessage} (${keyText("app.interrupt")} to interrupt)`,
 						);
 					}
-				} else {
-					// Queue message for when loadingAnimation is created (handles agent_start race)
-					this.pendingWorkingMessage = message;
 				}
 			},
 			setWorkingIndicator: (options) => this.setWorkingIndicator(options),
@@ -2591,17 +2589,10 @@ export class InteractiveMode {
 					this.ui,
 					(spinner) => theme.fg("accent", spinner),
 					(text) => theme.fg("muted", text),
-					this.defaultWorkingMessage,
+					this.workingMessage || this.defaultWorkingMessage,
 					this.workingIndicatorOptions,
 				);
 				this.statusContainer.addChild(this.loadingAnimation);
-				// Apply any pending working message queued before loader existed
-				if (this.pendingWorkingMessage !== undefined) {
-					if (this.pendingWorkingMessage) {
-						this.loadingAnimation.setMessage(this.pendingWorkingMessage);
-					}
-					this.pendingWorkingMessage = undefined;
-				}
 				this.ui.requestRender();
 				break;