fix(coding-agent): refresh thinking border from extensions

closes #3888

packages/coding-agent/CHANGELOG.md

@@ -8,6 +8,7 @@
 - Added `message_end` extension result support for replacing finalized messages, enabling extensions to override assistant usage cost ([#3982](https://github.com/badlogic/pi-mono/issues/3982)).
 - Added top-level `name` support to `pi.registerProvider()` so extension-registered providers can show a friendly name in `/login` ([#3956](https://github.com/badlogic/pi-mono/issues/3956)).
 - Added `ctx.ui.getEditorComponent()` so extensions can wrap the currently configured custom editor factory ([#3935](https://github.com/badlogic/pi-mono/issues/3935)).
+- Added a `thinking_level_select` extension event for observing thinking level changes ([#3888](https://github.com/badlogic/pi-mono/issues/3888)).
 
 ### Removed
 
@@ -15,6 +16,8 @@
 
 ### Fixed
 
+- Fixed blocked `edit` tool results rendering the rejection reason twice after interactive extension confirmation ([#3830](https://github.com/badlogic/pi-mono/issues/3830)).
+- Fixed extension-triggered thinking level changes refreshing the interactive editor border immediately ([#3888](https://github.com/badlogic/pi-mono/issues/3888)).
 - Fixed the coding-agent README See Also link to point at `@mariozechner/pi-agent-core` ([#4023](https://github.com/badlogic/pi-mono/issues/4023)).
 - Fixed `grep` and `find` tool argument injection for flag-like search patterns ([#4018](https://github.com/badlogic/pi-mono/issues/4018)).
 - Updated `@mariozechner/clipboard` to an attested release so package managers with trust policies do not reject installs ([#3946](https://github.com/badlogic/pi-mono/issues/3946)).

packages/coding-agent/docs/extensions.md

@@ -40,6 +40,7 @@ See [examples/extensions/](../examples/extensions/) for working implementations.
   - [Resource Events](#resource-events)
   - [Session Events](#session-events)
   - [Agent Events](#agent-events)
+  - [Model Events](#model-events)
   - [Tool Events](#tool-events)
 - [ExtensionContext](#extensioncontext)
 - [ExtensionCommandContext](#extensioncommandcontext)
@@ -323,8 +324,12 @@ user sends another prompt ◄─────────────────
   └─► session_tree
 
 /model or Ctrl+P (model selection/cycling)
+  ├─► thinking_level_select (if model change changes/clamps thinking level)
   └─► model_select
 
+thinking level changes (settings, keybinding, pi.setThinkingLevel())
+  └─► thinking_level_select
+
 exit (Ctrl+C, Ctrl+D, SIGHUP, SIGTERM)
   └─► session_shutdown
 ```
@@ -649,6 +654,21 @@ pi.on("model_select", async (event, ctx) => {
 
 Use this to update UI elements (status bars, footers) or perform model-specific initialization when the active model changes.
 
+#### thinking_level_select
+
+Fired when the thinking level changes. This is notification-only; handler return values are ignored.
+
+```typescript
+pi.on("thinking_level_select", async (event, ctx) => {
+  // event.level - newly selected thinking level
+  // event.previousLevel - previous thinking level
+
+  ctx.ui.setStatus("thinking", `thinking: ${event.level}`);
+});
+```
+
+Use this to update extension UI when `pi.setThinkingLevel()`, model changes, or built-in thinking-level controls change the active thinking level.
+
 ### Tool Events
 
 #### tool_call
@@ -1502,7 +1522,7 @@ if (model) {
 
 ### pi.getThinkingLevel() / pi.setThinkingLevel(level)
 
-Get or set the thinking level. Level is clamped to model capabilities (non-reasoning models always use "off").
+Get or set the thinking level. Level is clamped to model capabilities (non-reasoning models always use "off"). Changes emit `thinking_level_select`.
 
 ```typescript
 const current = pi.getThinkingLevel();  // "off" | "minimal" | "low" | "medium" | "high" | "xhigh"

packages/coding-agent/src/core/agent-session.ts

@@ -120,6 +120,7 @@ export type AgentSessionEvent =
 	  }
 	| { type: "compaction_start"; reason: "manual" | "threshold" | "overflow" }
 	| { type: "session_info_changed"; name: string | undefined }
+	| { type: "thinking_level_changed"; level: ThinkingLevel }
 	| {
 			type: "compaction_end";
 			reason: "manual" | "threshold" | "overflow";
@@ -1505,7 +1506,8 @@ export class AgentSession {
 		const effectiveLevel = availableLevels.includes(level) ? level : this._clampThinkingLevel(level, availableLevels);
 
 		// Only persist if actually changing
-		const isChanging = effectiveLevel !== this.agent.state.thinkingLevel;
+		const previousLevel = this.agent.state.thinkingLevel;
+		const isChanging = effectiveLevel !== previousLevel;
 
 		this.agent.state.thinkingLevel = effectiveLevel;
 
@@ -1514,6 +1516,12 @@ export class AgentSession {
 			if (this.supportsThinking() || effectiveLevel !== "off") {
 				this.settingsManager.setDefaultThinkingLevel(effectiveLevel);
 			}
+			this._emit({ type: "thinking_level_changed", level: effectiveLevel });
+			void this._extensionRunner.emit({
+				type: "thinking_level_select",
+				level: effectiveLevel,
+				previousLevel,
+			});
 		}
 	}
 

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

@@ -718,6 +718,13 @@ export interface ModelSelectEvent {
 	source: ModelSelectSource;
 }
 
+/** Fired when a new thinking level is selected */
+export interface ThinkingLevelSelectEvent {
+	type: "thinking_level_select";
+	level: ThinkingLevel;
+	previousLevel: ThinkingLevel;
+}
+
 // ============================================================================
 // User Bash Events
 // ============================================================================
@@ -958,6 +965,7 @@ export type ExtensionEvent =
 	| ToolExecutionUpdateEvent
 	| ToolExecutionEndEvent
 	| ModelSelectEvent
+	| ThinkingLevelSelectEvent
 	| UserBashEvent
 	| InputEvent
 	| ToolCallEvent
@@ -1111,6 +1119,7 @@ export interface ExtensionAPI {
 	on(event: "tool_execution_update", handler: ExtensionHandler<ToolExecutionUpdateEvent>): void;
 	on(event: "tool_execution_end", handler: ExtensionHandler<ToolExecutionEndEvent>): void;
 	on(event: "model_select", handler: ExtensionHandler<ModelSelectEvent>): void;
+	on(event: "thinking_level_select", handler: ExtensionHandler<ThinkingLevelSelectEvent>): void;
 	on(event: "tool_call", handler: ExtensionHandler<ToolCallEvent, ToolCallEventResult>): void;
 	on(event: "tool_result", handler: ExtensionHandler<ToolResultEvent, ToolResultEventResult>): void;
 	on(event: "user_bash", handler: ExtensionHandler<UserBashEvent, UserBashEventResult>): void;

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

@@ -2658,6 +2658,11 @@ export class InteractiveMode {
 				this.ui.requestRender();
 				break;
 
+			case "thinking_level_changed":
+				this.footer.invalidate();
+				this.updateEditorBorderColor();
+				break;
+
 			case "message_start":
 				if (event.message.role === "custom") {
 					this.addMessageToChat(event.message);