feat(coding-agent): pinned turn-ending provider errors above editor

- Added a persistent error banner so stream errors survive transcript scroll.
- Cleared the banner when the next turn starts.
- Skipped pinning for aborts and normal stops.

packages/coding-agent/src/modes/components/error-banner.ts

@@ -0,0 +1,33 @@
+import { Container, Spacer, Text } from "@oh-my-pi/pi-tui";
+import { getPreviewLines, TRUNCATE_LENGTHS } from "../../tools/render-utils";
+import { theme } from "../theme/theme";
+import { DynamicBorder } from "./dynamic-border";
+
+/** Max lines of the error message shown in the pinned banner. */
+const MAX_BANNER_LINES = 3;
+
+/**
+ * A persistent error banner pinned above the editor. Unlike the transcript
+ * "Error: …" line (which scrolls away as the conversation grows), this stays in
+ * the fixed region directly above the input so a turn that ended on a provider
+ * error — e.g. Anthropic's "Output blocked by content filtering policy" — cannot
+ * be missed. It is cleared when the next turn starts.
+ */
+export class ErrorBannerComponent extends Container {
+	constructor(message: string) {
+		super();
+		const lines = getPreviewLines(message, MAX_BANNER_LINES, TRUNCATE_LENGTHS.LINE);
+		if (lines.length === 0) {
+			lines.push("Unknown error");
+		}
+
+		this.addChild(new Spacer(1));
+		this.addChild(new DynamicBorder(str => theme.fg("error", str)));
+		this.addChild(new Text(theme.bold(theme.fg("error", `${theme.status.error} ${lines[0]}`)), 1, 0));
+		for (const line of lines.slice(1)) {
+			this.addChild(new Text(theme.fg("error", `  ${line}`), 1, 0));
+		}
+		this.addChild(new Text(theme.fg("dim", "Dismissed when you send your next message."), 1, 0));
+		this.addChild(new DynamicBorder(str => theme.fg("error", str)));
+	}
+}

packages/coding-agent/src/modes/controllers/event-controller.ts

@@ -204,6 +204,7 @@ export class EventController {
 		this.#readToolCallAssistantComponents.clear();
 		this.#assistantMessageStreaming = false;
 		this.#lastAssistantComponent = undefined;
+		this.ctx.clearPinnedError();
 		if (this.ctx.retryEscapeHandler) {
 			this.ctx.editor.onEscape = this.ctx.retryEscapeHandler;
 			this.ctx.retryEscapeHandler = undefined;
@@ -490,6 +491,16 @@ export class EventController {
 			this.#lastAssistantComponent.markTranscriptBlockFinalized();
 			this.ctx.streamingComponent = undefined;
 			this.ctx.streamingMessage = undefined;
+			// Pin a turn-ending provider error (e.g. Anthropic content-filter block)
+			// above the editor so it survives transcript scroll. Cleared at the next
+			// turn's agent_start.
+			if (
+				event.message.stopReason === "error" &&
+				event.message.errorMessage &&
+				!isSilentAbort(event.message.errorMessage)
+			) {
+				this.ctx.showPinnedError(event.message.errorMessage);
+			}
 			this.ctx.statusLine.invalidate();
 			this.ctx.updateEditorTopBorder();
 		}

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

@@ -96,6 +96,7 @@ import type { AssistantMessageComponent } from "./components/assistant-message";
 import type { BashExecutionComponent } from "./components/bash-execution";
 import { CustomEditor } from "./components/custom-editor";
 import { DynamicBorder } from "./components/dynamic-border";
+import { ErrorBannerComponent } from "./components/error-banner";
 import type { EvalExecutionComponent } from "./components/eval-execution";
 import type { HookEditorComponent } from "./components/hook-editor";
 import type { HookInputComponent } from "./components/hook-input";
@@ -264,6 +265,7 @@ export class InteractiveMode implements InteractiveModeContext {
 	todoContainer: Container;
 	btwContainer: Container;
 	omfgContainer: Container;
+	errorBannerContainer: Container;
 	editor: CustomEditor;
 	editorContainer: Container;
 	hookWidgetContainerAbove: Container;
@@ -405,6 +407,7 @@ export class InteractiveMode implements InteractiveModeContext {
 		this.todoContainer = new Container();
 		this.btwContainer = new Container();
 		this.omfgContainer = new Container();
+		this.errorBannerContainer = new Container();
 		this.editor = new CustomEditor(getEditorTheme());
 		this.editor.setUseTerminalCursor(this.ui.getShowHardwareCursor());
 		this.editor.setAutocompleteMaxVisible(settings.get("autocompleteMaxVisible"));
@@ -566,6 +569,7 @@ export class InteractiveMode implements InteractiveModeContext {
 		this.ui.addChild(this.todoContainer);
 		this.ui.addChild(this.btwContainer);
 		this.ui.addChild(this.omfgContainer);
+		this.ui.addChild(this.errorBannerContainer);
 		this.ui.addChild(this.statusLine); // Only renders hook statuses (main status in editor border)
 		this.ui.addChild(this.hookWidgetContainerAbove);
 		this.ui.addChild(this.editorContainer);
@@ -2503,6 +2507,19 @@ export class InteractiveMode implements InteractiveModeContext {
 		this.#uiHelpers.showError(message);
 	}
 
+	showPinnedError(message: string): void {
+		if (this.isBackgrounded) return;
+		this.errorBannerContainer.clear();
+		this.errorBannerContainer.addChild(new ErrorBannerComponent(message));
+		this.ui.requestRender();
+	}
+
+	clearPinnedError(): void {
+		if (this.errorBannerContainer.children.length === 0) return;
+		this.errorBannerContainer.clear();
+		this.ui.requestRender();
+	}
+
 	showWarning(message: string): void {
 		this.#uiHelpers.showWarning(message);
 	}
@@ -2723,6 +2740,7 @@ export class InteractiveMode implements InteractiveModeContext {
 		this.#btwController.dispose();
 		this.#omfgController.dispose();
 		this.#extensionUiController.clearExtensionTerminalInputListeners();
+		this.clearPinnedError();
 		this.#planReviewContainer = undefined;
 	}
 

packages/coding-agent/src/modes/types.ts

@@ -76,6 +76,7 @@ export interface InteractiveModeContext {
 	todoContainer: Container;
 	btwContainer: Container;
 	omfgContainer: Container;
+	errorBannerContainer: Container;
 	editor: CustomEditor;
 	editorContainer: Container;
 	hookWidgetContainerAbove: Container;
@@ -159,6 +160,8 @@ export interface InteractiveModeContext {
 	// UI helpers
 	showStatus(message: string, options?: { dim?: boolean }): void;
 	showError(message: string): void;
+	showPinnedError(message: string): void;
+	clearPinnedError(): void;
 	showWarning(message: string): void;
 	showNewVersionNotification(newVersion: string): void;
 	clearEditor(): void;