diff --git a/litellm/_uuid.py b/litellm/_uuid.py
index e9578b7287f..b68a1e4264f 100644
--- a/litellm/_uuid.py
+++ b/litellm/_uuid.py
@@ -1,10 +1,13 @@
 """
 Internal unified UUID helper.
 
-Always uses fastuuid for performance.
+Uses fastuuid for performance when installed, otherwise falls back to stdlib uuid.
 """
 
-import fastuuid as _uuid
+try:
+    import fastuuid as _uuid
+except ImportError:
+    import uuid as _uuid
 
 # Expose a module-like alias so callers can use: uuid.uuid4()
 uuid = _uuid
@@ -13,3 +16,4 @@ uuid = _uuid
 def uuid4():
     """Return a UUID4 using the selected backend."""
     return uuid.uuid4()
+
diff --git a/litellm/litellm_core_utils/reasoning_effort_utils.py b/litellm/litellm_core_utils/reasoning_effort_utils.py
index 5987392d070..7db390e46bd 100644
--- a/litellm/litellm_core_utils/reasoning_effort_utils.py
+++ b/litellm/litellm_core_utils/reasoning_effort_utils.py
@@ -1,22 +1,33 @@
-from typing import Literal
+from typing import Literal, Optional
 
 from litellm.constants import (
     DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET,
     DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_MAX_THINKING_BUDGET,
     DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_MINIMAL_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET,
 )
 
-OpenAIStyleReasoningEffort = Literal["minimal", "low", "medium", "high"]
+OpenAIStyleReasoningEffort = Literal[
+    "minimal", "low", "medium", "high", "xhigh", "max"
+]
 
 
 def reasoning_effort_from_thinking_budget(
-    budget_tokens: int,
+    budget_tokens: Optional[int],
 ) -> OpenAIStyleReasoningEffort:
     """Bucket an Anthropic ``thinking.budget_tokens`` into an OpenAI-style
     ``reasoning_effort`` using the shared ``DEFAULT_REASONING_EFFORT_*_THINKING_BUDGET``
     thresholds, so every backend that translates a budget into an effort label
     reads the same numbers.
     """
+    if budget_tokens is None or budget_tokens <= 0:
+        return "minimal"
+    if budget_tokens >= DEFAULT_REASONING_EFFORT_MAX_THINKING_BUDGET:
+        return "max"
+    if budget_tokens >= DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET:
+        return "xhigh"
     if budget_tokens >= DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET:
         return "high"
     if budget_tokens >= DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET:
@@ -24,3 +35,31 @@ def reasoning_effort_from_thinking_budget(
     if budget_tokens >= DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET:
         return "low"
     return "minimal"
+
+
+def thinking_budget_from_reasoning_effort(
+    reasoning_effort: Optional[str],
+) -> int:
+    """Convert an OpenAI-style ``reasoning_effort`` string into a default
+    thinking token budget.
+    """
+    if not reasoning_effort:
+        return DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET
+
+    effort_lower = reasoning_effort.lower()
+    if effort_lower == "max":
+        return DEFAULT_REASONING_EFFORT_MAX_THINKING_BUDGET
+    if effort_lower == "xhigh":
+        return DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET
+    if effort_lower == "high":
+        return DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET
+    if effort_lower == "medium":
+        return DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET
+    if effort_lower == "low":
+        return DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET
+    if effort_lower == "minimal":
+        return DEFAULT_REASONING_EFFORT_MINIMAL_THINKING_BUDGET
+    if effort_lower == "none":
+        return 0
+    return DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET
+
diff --git a/tests/test_litellm/test_reasoning_effort_utils.py b/tests/test_litellm/test_reasoning_effort_utils.py
new file mode 100644
index 00000000000..35aafdf3ee9
--- /dev/null
+++ b/tests/test_litellm/test_reasoning_effort_utils.py
@@ -0,0 +1,39 @@
+"""
+Unit tests for litellm_core_utils/reasoning_effort_utils.py.
+"""
+
+from litellm.constants import (
+    DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_MAX_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_MINIMAL_THINKING_BUDGET,
+    DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET,
+)
+from litellm.litellm_core_utils.reasoning_effort_utils import (
+    reasoning_effort_from_thinking_budget,
+    thinking_budget_from_reasoning_effort,
+)
+
+
+def test_reasoning_effort_from_thinking_budget_levels():
+    assert reasoning_effort_from_thinking_budget(None) == "minimal"
+    assert reasoning_effort_from_thinking_budget(0) == "minimal"
+    assert reasoning_effort_from_thinking_budget(-10) == "minimal"
+    assert reasoning_effort_from_thinking_budget(DEFAULT_REASONING_EFFORT_MINIMAL_THINKING_BUDGET) == "minimal"
+    assert reasoning_effort_from_thinking_budget(DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET) == "low"
+    assert reasoning_effort_from_thinking_budget(DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET) == "medium"
+    assert reasoning_effort_from_thinking_budget(DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET) == "high"
+    assert reasoning_effort_from_thinking_budget(DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET) == "xhigh"
+    assert reasoning_effort_from_thinking_budget(DEFAULT_REASONING_EFFORT_MAX_THINKING_BUDGET) == "max"
+
+
+def test_thinking_budget_from_reasoning_effort_levels():
+    assert thinking_budget_from_reasoning_effort(None) == DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET
+    assert thinking_budget_from_reasoning_effort("none") == 0
+    assert thinking_budget_from_reasoning_effort("minimal") == DEFAULT_REASONING_EFFORT_MINIMAL_THINKING_BUDGET
+    assert thinking_budget_from_reasoning_effort("low") == DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET
+    assert thinking_budget_from_reasoning_effort("medium") == DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET
+    assert thinking_budget_from_reasoning_effort("high") == DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET
+    assert thinking_budget_from_reasoning_effort("xhigh") == DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET
+    assert thinking_budget_from_reasoning_effort("max") == DEFAULT_REASONING_EFFORT_MAX_THINKING_BUDGET
diff --git a/tests/test_litellm/test_uuid_helper.py b/tests/test_litellm/test_uuid_helper.py
index 589d3f96a17..3763f3afbaf 100644
--- a/tests/test_litellm/test_uuid_helper.py
+++ b/tests/test_litellm/test_uuid_helper.py
@@ -1,14 +1,20 @@
 import importlib
+import uuid as stdlib_uuid
 
 
-def test_uses_fastuuid_and_uuid4_works():
+def test_uses_fastuuid_or_stdlib_and_uuid4_works():
     mod = importlib.import_module("litellm._uuid")
-    fastuuid_mod = importlib.import_module("fastuuid")
     assert hasattr(mod, "uuid4")
     assert hasattr(mod, "uuid")
-    assert mod.uuid is fastuuid_mod
+
+    try:
+        fastuuid_mod = importlib.import_module("fastuuid")
+        assert mod.uuid is fastuuid_mod
+    except ImportError:
+        assert mod.uuid is stdlib_uuid
 
     # Ensure uuid4 returns something that looks like a UUID string
     val = str(mod.uuid4())
     assert isinstance(val, str)
     assert len(val) >= 8
+