diff --git a/packages/pi-coding-agent/src/core/agent-session.ts b/packages/pi-coding-agent/src/core/agent-session.ts
index a5dfa2335..285e32516 100644
--- a/packages/pi-coding-agent/src/core/agent-session.ts
+++ b/packages/pi-coding-agent/src/core/agent-session.ts
@@ -246,6 +246,12 @@ export class AgentSession {
 	private _retryPromise: Promise<void> | undefined = undefined;
 	private _retryResolve: (() => void) | undefined = undefined;
 
+	// Cumulative session stats — survives compaction (#1423)
+	private _cumulativeCost = 0;
+	private _cumulativeInputTokens = 0;
+	private _cumulativeOutputTokens = 0;
+	private _cumulativeToolCalls = 0;
+
 	// Bash execution state
 	private _bashAbortController: AbortController | undefined = undefined;
 	private _pendingBashMessages: BashExecutionMessage[] = [];
@@ -438,7 +444,13 @@ export class AgentSession {
 			if (event.message.role === "assistant") {
 				this._lastAssistantMessage = event.message;
 
+				// Accumulate session stats that survive compaction (#1423)
 				const assistantMsg = event.message as AssistantMessage;
+				this._cumulativeCost += assistantMsg.usage?.cost?.total ?? 0;
+				this._cumulativeInputTokens += assistantMsg.usage?.input ?? 0;
+				this._cumulativeOutputTokens += assistantMsg.usage?.output ?? 0;
+				this._cumulativeToolCalls += assistantMsg.content.filter((c) => c.type === "toolCall").length;
+
 				if (assistantMsg.stopReason !== "error") {
 					this._overflowRecoveryAttempted = false;
 				}
@@ -3230,17 +3242,17 @@ export class AgentSession {
 			sessionId: this.sessionId,
 			userMessages,
 			assistantMessages,
-			toolCalls,
+			toolCalls: Math.max(toolCalls, this._cumulativeToolCalls),
 			toolResults,
 			totalMessages: state.messages.length,
 			tokens: {
-				input: totalInput,
-				output: totalOutput,
+				input: Math.max(totalInput, this._cumulativeInputTokens),
+				output: Math.max(totalOutput, this._cumulativeOutputTokens),
 				cacheRead: totalCacheRead,
 				cacheWrite: totalCacheWrite,
-				total: totalInput + totalOutput + totalCacheRead + totalCacheWrite,
+				total: Math.max(totalInput + totalOutput, this._cumulativeInputTokens + this._cumulativeOutputTokens) + totalCacheRead + totalCacheWrite,
 			},
-			cost: totalCost,
+			cost: Math.max(totalCost, this._cumulativeCost),
 		};
 	}
 
diff --git a/src/tests/file-watcher.test.ts b/src/tests/file-watcher.test.ts
index e8dc7fd00..38040cdc6 100644
--- a/src/tests/file-watcher.test.ts
+++ b/src/tests/file-watcher.test.ts
@@ -54,10 +54,11 @@ test("settings.json change emits settings-changed event", async () => {
 	const bus = createMockEventBus();
 
 	await startFileWatcher(dir, bus);
+	await delay(200);
 
 	writeFileSync(join(dir, "settings.json"), JSON.stringify({ updated: true }));
 	// Wait for debounce (300ms) + filesystem propagation
-	await delay(600);
+	await delay(800);
 
 	const matched = bus.events.filter((e) => e.channel === "settings-changed");
 	assert.ok(matched.length > 0, "should emit settings-changed event");
@@ -68,9 +69,10 @@ test("auth.json change emits auth-changed event", async () => {
 	const bus = createMockEventBus();
 
 	await startFileWatcher(dir, bus);
+	await delay(200);
 
 	writeFileSync(join(dir, "auth.json"), JSON.stringify({ token: "new" }));
-	await delay(600);
+	await delay(800);
 
 	const matched = bus.events.filter((e) => e.channel === "auth-changed");
 	assert.ok(matched.length > 0, "should emit auth-changed event");
@@ -81,9 +83,10 @@ test("models.json change emits models-changed event", async () => {
 	const bus = createMockEventBus();
 
 	await startFileWatcher(dir, bus);
+	await delay(200);
 
 	writeFileSync(join(dir, "models.json"), JSON.stringify({ model: "new" }));
-	await delay(600);
+	await delay(800);
 
 	const matched = bus.events.filter((e) => e.channel === "models-changed");
 	assert.ok(matched.length > 0, "should emit models-changed event");
@@ -133,7 +136,7 @@ test("debouncing coalesces rapid changes into one event", async () => {
 	for (let i = 0; i < 5; i++) {
 		writeFileSync(join(dir, "settings.json"), JSON.stringify({ i }));
 	}
-	await delay(600);
+	await delay(800);
 
 	const matched = bus.events.filter((e) => e.channel === "settings-changed");
 	assert.strictEqual(