fix(rust_bridge): isolate OCR enable flag and drop dead messages global toggle

use_litellm_rust only mutates the OCR enabled flag when configuring OCR (or
called with no bridge kwargs, preserving the legacy contract), so configuring
only the messages bridge no longer flips OCR state.

Remove the vestigial global enabled/env state from the messages bridge. Routing
is controlled per deployment by rust:true in the shared handler gate, so the
messages module never consulted the global toggle; drop it rather than leave a
no-op switch.

Co-Authored-By: Ishaan Jaffer <155045088+ishaan-berri@users.noreply.github.com>

basedpyright-code-budget.json

@@ -24,7 +24,7 @@
     "limit": 42
   },
   "reportExplicitAny": {
-    "limit": 10393
+    "limit": 10389
   },
   "reportFunctionMemberAccess": {
     "limit": 11

litellm/rust_bridge/messages.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-import os
 from dataclasses import dataclass
 from typing import Awaitable, Final, Protocol, Union, cast
 
@@ -46,43 +45,26 @@ class _Unset:
 _UNSET: Final[_Unset] = _Unset()
 
 
-def _env_enables_rust_messages() -> bool:
-    return os.getenv("LITELLM_USE_RUST_MESSAGES", "").strip().lower() in {
-        "1",
-        "true",
-        "yes",
-        "on",
-    }
-
-
 @dataclass(slots=True)
 class _RustMessagesState:
-    enabled: bool
     messages: RustMessages | None = None
     amessages: RustAmessages | None = None
 
 
-_STATE: Final[_RustMessagesState] = _RustMessagesState(enabled=_env_enables_rust_messages())
+_STATE: Final[_RustMessagesState] = _RustMessagesState()
 
 
 def set_rust_messages(
-    enabled: bool | _Unset = _UNSET,
     *,
     messages: RustMessages | None | _Unset = _UNSET,
     amessages: RustAmessages | None | _Unset = _UNSET,
 ) -> None:
-    if not isinstance(enabled, _Unset):
-        _STATE.enabled = enabled
     if not isinstance(messages, _Unset):
         _STATE.messages = messages
     if not isinstance(amessages, _Unset):
         _STATE.amessages = amessages
 
 
-def rust_messages_enabled() -> bool:
-    return _STATE.enabled
-
-
 def load_rust_messages() -> RustMessages | None:
     if _STATE.messages is not None:
         return _STATE.messages

litellm/rust_bridge/ocr.py

@@ -73,21 +73,24 @@ def use_litellm_rust(
     amessages: RustAmessages | None | _Unset = _UNSET,
 ) -> None:
     global _rust_ocr_enabled, _rust_ocr_impl, _rust_aocr_impl
-    _rust_ocr_enabled = enabled
+    configuring_ocr = not isinstance(ocr, _Unset) or not isinstance(aocr, _Unset)
+    configuring_messages = not isinstance(messages, _Unset) or not isinstance(amessages, _Unset)
+    if configuring_ocr or not configuring_messages:
+        _rust_ocr_enabled = enabled
     if not isinstance(ocr, _Unset):
         _rust_ocr_impl = ocr
     if not isinstance(aocr, _Unset):
         _rust_aocr_impl = aocr
-    if isinstance(messages, _Unset) and isinstance(amessages, _Unset):
+    if not configuring_messages:
         return
     from litellm.rust_bridge.messages import set_rust_messages
 
     if not isinstance(messages, _Unset) and not isinstance(amessages, _Unset):
-        set_rust_messages(enabled, messages=messages, amessages=amessages)
+        set_rust_messages(messages=messages, amessages=amessages)
     elif not isinstance(messages, _Unset):
-        set_rust_messages(enabled, messages=messages)
+        set_rust_messages(messages=messages)
     else:
-        set_rust_messages(enabled, amessages=amessages)
+        set_rust_messages(amessages=amessages)
 
 
 def rust_ocr_enabled() -> bool:

tests/documentation_tests/test_env_keys.py

@@ -28,7 +28,6 @@ EXCLUDED_GUARD_ONLY_VARS = {
 # environment settings docs until the feature is ready for broad use.
 EXCLUDED_ROLLOUT_FLAGS = {
     "LITELLM_USE_RUST_OCR",
-    "LITELLM_USE_RUST_MESSAGES",
 }
 
 EXCLUDED_TERMINAL_VARS = {

tests/test_litellm/rust_bridge/test_messages.py

@@ -109,6 +109,27 @@ def test_load_rust_messages_returns_injected_impl():
     assert rust_messages.load_rust_messages() is bridge
 
 
+def test_configuring_messages_does_not_enable_ocr():
+    from litellm.rust_bridge.ocr import rust_ocr_enabled
+
+    litellm.use_litellm_rust(False)
+    assert rust_ocr_enabled() is False
+
+    litellm.use_litellm_rust(True, messages=RecordingMessages())
+
+    assert rust_ocr_enabled() is False
+
+
+def test_bare_use_litellm_rust_still_toggles_ocr():
+    from litellm.rust_bridge.ocr import rust_ocr_enabled
+
+    litellm.use_litellm_rust(True)
+    assert rust_ocr_enabled() is True
+
+    litellm.use_litellm_rust(False)
+    assert rust_ocr_enabled() is False
+
+
 def test_load_rust_amessages_returns_injected_impl():
     bridge = RecordingAsyncMessages()
     litellm.use_litellm_rust(True, amessages=bridge)

type-discipline-budget.json

@@ -15,7 +15,7 @@
     "limit": 0
   },
   "LIT006": {
-    "limit": 1112
+    "limit": 1111
   },
   "LIT007": {
     "limit": 0