From bc830c16f1f0695dd336b4e04bf0e65849b432c2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aleix=20Conchillo=20Flaqu=C3=A9?= <aleix@daily.co>
Date: Thu, 19 Feb 2026 20:52:00 -0800
Subject: [PATCH 1/2] Fix mutable default arguments in LLMContextAggregatorPair

Replace mutable default parameter values with None and instantiate
inside the method body to avoid shared state across calls.
---
 .../processors/aggregators/llm_response_universal.py        | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/pipecat/processors/aggregators/llm_response_universal.py b/src/pipecat/processors/aggregators/llm_response_universal.py
index c41885655..e5884a868 100644
--- a/src/pipecat/processors/aggregators/llm_response_universal.py
+++ b/src/pipecat/processors/aggregators/llm_response_universal.py
@@ -1257,8 +1257,8 @@ class LLMContextAggregatorPair:
         self,
         context: LLMContext,
         *,
-        user_params: LLMUserAggregatorParams = LLMUserAggregatorParams(),
-        assistant_params: LLMAssistantAggregatorParams = LLMAssistantAggregatorParams(),
+        user_params: Optional[LLMUserAggregatorParams] = None,
+        assistant_params: Optional[LLMAssistantAggregatorParams] = None,
     ):
         """Initialize the LLM context aggregator pair.
 
@@ -1267,6 +1267,8 @@ class LLMContextAggregatorPair:
             user_params: Parameters for the user context aggregator.
             assistant_params: Parameters for the assistant context aggregator.
         """
+        user_params = user_params or LLMUserAggregatorParams()
+        assistant_params = assistant_params or LLMAssistantAggregatorParams()
         self._user = LLMUserAggregator(context, params=user_params)
         self._assistant = LLMAssistantAggregator(context, params=assistant_params)
 

From 2024285c751ed382789e2d34c648bb2d87ae8a1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Aleix=20Conchillo=20Flaqu=C3=A9?= <aleix@daily.co>
Date: Thu, 19 Feb 2026 20:52:31 -0800
Subject: [PATCH 2/2] Add changelog entries for PR #3782

---
 changelog/3782.fixed.md | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog/3782.fixed.md

diff --git a/changelog/3782.fixed.md b/changelog/3782.fixed.md
new file mode 100644
index 000000000..7d21fdeab
--- /dev/null
+++ b/changelog/3782.fixed.md
@@ -0,0 +1 @@
+- Fixed mutable default arguments in `LLMContextAggregatorPair.__init__()` that could cause shared state across instances.