From b9cd557d1d6773abc4e1ddc22c4758b9ecda2c0c Mon Sep 17 00:00:00 2001
From: Mario Zechner <badlogicgames@gmail.com>
Date: Thu, 16 Apr 2026 23:51:26 +0200
Subject: [PATCH] fix(agent): guard afterToolCall hook errors in finalization

closes #3084
---
 packages/agent/CHANGELOG.md      |  4 ++++
 packages/agent/src/agent-loop.ts | 39 ++++++++++++++++++--------------
 2 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/packages/agent/CHANGELOG.md b/packages/agent/CHANGELOG.md
index 2d7226e0..5855835f 100644
--- a/packages/agent/CHANGELOG.md
+++ b/packages/agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed parallel tool-call finalization to convert `afterToolCall` hook throws into error tool results instead of aborting the batch ([#3084](https://github.com/badlogic/pi-mono/issues/3084))
+
 ## [0.67.6] - 2026-04-16
 
 ## [0.67.5] - 2026-04-16
diff --git a/packages/agent/src/agent-loop.ts b/packages/agent/src/agent-loop.ts
index 586a1b7d..8482c5ce 100644
--- a/packages/agent/src/agent-loop.ts
+++ b/packages/agent/src/agent-loop.ts
@@ -571,23 +571,28 @@ async function finalizeExecutedToolCall(
 	let isError = executed.isError;
 
 	if (config.afterToolCall) {
-		const afterResult = await config.afterToolCall(
-			{
-				assistantMessage,
-				toolCall: prepared.toolCall,
-				args: prepared.args,
-				result,
-				isError,
-				context: currentContext,
-			},
-			signal,
-		);
-		if (afterResult) {
-			result = {
-				content: afterResult.content ?? result.content,
-				details: afterResult.details ?? result.details,
-			};
-			isError = afterResult.isError ?? isError;
+		try {
+			const afterResult = await config.afterToolCall(
+				{
+					assistantMessage,
+					toolCall: prepared.toolCall,
+					args: prepared.args,
+					result,
+					isError,
+					context: currentContext,
+				},
+				signal,
+			);
+			if (afterResult) {
+				result = {
+					content: afterResult.content ?? result.content,
+					details: afterResult.details ?? result.details,
+				};
+				isError = afterResult.isError ?? isError;
+			}
+		} catch (error) {
+			result = createErrorToolResult(error instanceof Error ? error.message : String(error));
+			isError = true;
 		}
 	}