diff --git a/packages/services/agent-service/src/infrastructure/engines/claude-agent-sdk/claude-agent-sdk-engine.ts b/packages/services/agent-service/src/infrastructure/engines/claude-agent-sdk/claude-agent-sdk-engine.ts
index 95742a5..5326539 100644
--- a/packages/services/agent-service/src/infrastructure/engines/claude-agent-sdk/claude-agent-sdk-engine.ts
+++ b/packages/services/agent-service/src/infrastructure/engines/claude-agent-sdk/claude-agent-sdk-engine.ts
@@ -109,6 +109,9 @@ export class ClaudeAgentSdkEngine implements AgentEnginePort {
           abortController,
           allowDangerouslySkipPermissions: true,
           permissionMode: 'bypassPermissions',
+          stderr: (data: string) => {
+            this.logger.debug(`SDK stderr (${params.sessionId}): ${data.trim()}`);
+          },
           canUseTool: async (toolName, toolInput, { signal }) => {
             const riskLevel = this.classifyToolRisk(toolName, toolInput);