Update CHANGELOG and refactor ConversationAgent to prevent unnecessary stop-sequence injection

CHANGELOG.yaml

@@ -5,6 +5,7 @@
   - "Pydantic Migration: Internal data models across the codebase converted to pydantic for stricter validation. No user-visible behavior changes."
   fixes:
   - "Game Loop Event: Fixed an internal scene-loop event being constructed with the wrong scene reference, surfaced by the pydantic migration."
+  - "Conversation Agent: Stopped injecting `#` into the LLM stop-sequence list on every conversation turn. The conversation agent's prompt-parameter hook now only wipes character-name stop sequences when the `inject_character_names_into_stop` setting is disabled, and is a no-op otherwise."
 0.37.0:
   features:
   - "System Prompt Template Variable: Added {{ system_prompt }} template variable for system prompt overrides. Use it to include the default system prompt within a custom override, at both the app and client level."

src/talemate/agents/conversation/__init__.py

@@ -539,9 +539,5 @@ class ConversationAgent(MemoryRAGMixin, Agent):
     def inject_prompt_paramters(
         self, prompt_param: dict, kind: str, agent_function_name: str
     ):
-        if (
-            prompt_param.get("extra_stopping_strings") is None
-            or not self.inject_character_names_into_stop
-        ):
+        if not self.inject_character_names_into_stop:
             prompt_param["extra_stopping_strings"] = []
-        prompt_param["extra_stopping_strings"] += ["#"]

tests/test_conversation_agent.py

@@ -297,13 +297,15 @@ class TestAllowRepetitionBreakAndInject:
             conversation.allow_repetition_break("conversation", "build_prompt") is False
         )
 
-    def test_inject_prompt_parameters_appends_hash(self, conversation_scene):
+    def test_inject_prompt_parameters_noop_with_inject_enabled_and_empty(
+        self, conversation_scene
+    ):
         _, conversation, _ = conversation_scene
         params = {}
         conversation.inject_prompt_paramters(params, "conversation", "converse")
-        # When inject_character_names_into_stop is True (default), the
-        # function still wraps with extra_stopping_strings = [], then adds "#".
-        assert params.get("extra_stopping_strings", []) == ["#"]
+        # When inject_character_names_into_stop is True (default) and no
+        # stopping strings are present, the function leaves params untouched.
+        assert "extra_stopping_strings" not in params
 
     def test_inject_prompt_parameters_resets_when_inject_disabled(
         self, conversation_scene
@@ -314,22 +316,23 @@ class TestAllowRepetitionBreakAndInject:
         ].value = False
         params = {"extra_stopping_strings": ["EXISTING"]}
         conversation.inject_prompt_paramters(params, "conversation", "converse")
-        # The function resets to [] when inject_character_names_into_stop is
-        # False, and then appends "#".
-        assert params["extra_stopping_strings"] == ["#"]
+        # When inject_character_names_into_stop is False, any stopping
+        # strings already populated (e.g. character names added by the
+        # client) are wiped.
+        assert params["extra_stopping_strings"] == []
 
     def test_inject_prompt_parameters_preserves_existing_with_inject_enabled(
         self, conversation_scene
     ):
         _, conversation, _ = conversation_scene
         # When inject_character_names_into_stop is True AND extra_stopping_strings
-        # is already a list, it is preserved (existing list + "#").
+        # is already populated, it is left untouched.
         conversation.actions["generation_override"].config[
             "inject_character_names_into_stop"
         ].value = True
         params = {"extra_stopping_strings": ["EXISTING"]}
         conversation.inject_prompt_paramters(params, "conversation", "converse")
-        assert params["extra_stopping_strings"] == ["EXISTING", "#"]
+        assert params["extra_stopping_strings"] == ["EXISTING"]
 
 
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