diff --git a/src/ai_client.py b/src/ai_client.py
index 24922a32..583f0406 100644
--- a/src/ai_client.py
+++ b/src/ai_client.py
@@ -43,6 +43,7 @@ from src import mcp_tool_specs
 from src import mma_prompts
 from src import performance_monitor
 from src import project_manager
+from src import provider_state
 from src.vendor_capabilities import VendorCapabilities, get_capabilities
 
 # TODO(Ed): Eliminate these?
@@ -109,29 +110,29 @@ _gemini_cached_file_paths: list[str]       = []
 _GEMINI_CACHE_TTL: int = 3600
 
 _anthropic_client:       Optional[anthropic.Anthropic] = None
-_anthropic_history:      list[Metadata]          = []
-_anthropic_history_lock: threading.Lock = threading.Lock()
+_anthropic_history = provider_state.get_history("anthropic")
+_anthropic_history_lock = _anthropic_history.lock
 
 _deepseek_client:       Any                  = None
-_deepseek_history:      list[Metadata] = []
-_deepseek_history_lock: threading.Lock = threading.Lock()
+_deepseek_history = provider_state.get_history("deepseek")
+_deepseek_history_lock = _deepseek_history.lock
 
 _minimax_client:       Any                  = None
-_minimax_history:      list[Metadata] = []
-_minimax_history_lock: threading.Lock = threading.Lock()
+_minimax_history = provider_state.get_history("minimax")
+_minimax_history_lock = _minimax_history.lock
 
 _qwen_client:       Any                  = None
-_qwen_history:      list[Metadata] = []
-_qwen_history_lock: threading.Lock = threading.Lock()
+_qwen_history = provider_state.get_history("qwen")
+_qwen_history_lock = _qwen_history.lock
 _qwen_region:       str            = "china"
 
 _grok_client:       Any                  = None
-_grok_history:      list[Metadata] = []
-_grok_history_lock: threading.Lock = threading.Lock()
+_grok_history = provider_state.get_history("grok")
+_grok_history_lock = _grok_history.lock
 
 _llama_client:       Any                  = None
-_llama_history:      list[Metadata] = []
-_llama_history_lock: threading.Lock       = threading.Lock()
+_llama_history = provider_state.get_history("llama")
+_llama_history_lock = _llama_history.lock
 _llama_base_url:     str = "http://localhost:11434/v1"
 _llama_api_key:      str = "ollama"
 
@@ -461,10 +462,10 @@ def reset_session() -> None:
  """Clears conversation history and resets provider-specific session state."""
  global _gemini_client,        _gemini_chat,            _gemini_cache
  global _gemini_cache_md_hash, _gemini_cache_created_at, _gemini_cached_file_paths
- global _anthropic_client,     _anthropic_history
- global _deepseek_client,      _deepseek_history
- global _minimax_client,       _minimax_history
- global _qwen_client,          _qwen_history
+ global _anthropic_client
+ global _deepseek_client
+ global _minimax_client
+ global _qwen_client
  global _CACHED_ANTHROPIC_TOOLS, _CACHED_DEEPSEEK_TOOLS
  global _gemini_cli_adapter
  if _gemini_client and _gemini_cache:
@@ -475,29 +476,18 @@ def reset_session() -> None:
  _gemini_cache_md_hash     = None
  _gemini_cache_created_at  = None
  _gemini_cached_file_paths = []
- 
+
  # Preserve binary_path if adapter exists
  old_path            = _gemini_cli_adapter.binary_path if _gemini_cli_adapter else "gemini"
  _gemini_cli_adapter = GeminiCliAdapter(binary_path=old_path)
- 
+
  _anthropic_client = None
- with _anthropic_history_lock:
-  _anthropic_history = []
+ provider_state.clear_all()
  _deepseek_client    = None
- with _deepseek_history_lock:
-  _deepseek_history = []
  _minimax_client    = None
- with _minimax_history_lock:
-  _minimax_history       = []
  _qwen_client    = None
- with _qwen_history_lock:
-  _qwen_history       = []
  _grok_client = None
- with _grok_history_lock:
-  _grok_history = []
  _llama_client  = None
- with _llama_history_lock:
-  _llama_history = []
  _llama_base_url = "http://localhost:11434/v1"
  _llama_api_key  = "ollama"
  _CACHED_ANTHROPIC_TOOLS = None
diff --git a/src/provider_state.py b/src/provider_state.py
index 78e374b4..c1302b22 100644
--- a/src/provider_state.py
+++ b/src/provider_state.py
@@ -22,11 +22,28 @@ from dataclasses import dataclass, field
 from src.type_aliases import HistoryMessage, Metadata
 
 
+@dataclass
 @dataclass
 class ProviderHistory:
  messages: list[HistoryMessage] = field(default_factory=list)
  lock: threading.Lock = field(default_factory=threading.Lock)
 
+ def __bool__(self) -> bool:
+  with self.lock:
+   return bool(self.messages)
+
+ def __len__(self) -> int:
+  with self.lock:
+   return len(self.messages)
+
+ def __iter__(self):
+  with self.lock:
+   return iter(list(self.messages))
+
+ def __getitem__(self, idx):
+  with self.lock:
+   return self.messages[idx]
+
  def append(self, message: HistoryMessage) -> None:
   with self.lock:
    self.messages.append(message)
@@ -54,6 +71,16 @@ _PROVIDER_HISTORIES: dict[str, ProviderHistory] = {
 }
 
 
+_PROVIDER_HISTORIES: dict[str, ProviderHistory] = {
+ "anthropic": ProviderHistory(),
+ "deepseek": ProviderHistory(),
+ "minimax": ProviderHistory(),
+ "qwen": ProviderHistory(),
+ "grok": ProviderHistory(),
+ "llama": ProviderHistory(),
+}
+
+
 def get_history(provider: str) -> ProviderHistory:
  if provider not in _PROVIDER_HISTORIES:
   raise KeyError(f"Unknown provider: {provider!r}")