diff --git a/litellm/litellm_core_utils/total_deadline.py b/litellm/litellm_core_utils/total_deadline.py
new file mode 100644
index 00000000000..f44eb97719d
--- /dev/null
+++ b/litellm/litellm_core_utils/total_deadline.py
@@ -0,0 +1,197 @@
+"""
+One wall-clock budget for a whole non-streaming proxy request (``total_timeout``): the proxy opens it,
+and the router reads it to refuse a retry backoff that cannot finish in time. A request that turns out
+to stream or run in the background is not bounded: a body ``total_timeout`` refuses it, a header one
+(often set globally on a client) lets it go unbounded.
+"""
+
+import asyncio
+import contextlib
+import math
+import sys
+from collections.abc import AsyncGenerator, Callable, Generator, Mapping
+from contextvars import ContextVar
+from dataclasses import dataclass
+from typing import Final
+
+from litellm._logging import verbose_router_logger
+
+if sys.version_info >= (3, 11):
+    from asyncio import Timeout as _Scope
+    from asyncio import timeout_at as _timeout_at
+
+    _ScopeTimeout: Final = TimeoutError
+
+    def _expired(scope: _Scope) -> bool:
+        return scope.expired()
+
+    def _disarm(scope: _Scope) -> None:
+        scope.reschedule(None)
+
+    def _rearm(scope: _Scope, when: float) -> None:
+        scope.reschedule(when)
+
+else:
+    from async_timeout import Timeout as _Scope
+    from async_timeout import timeout_at as _timeout_at
+
+    _ScopeTimeout: Final = asyncio.TimeoutError
+
+    def _expired(scope: _Scope) -> bool:
+        return scope.expired
+
+    def _disarm(scope: _Scope) -> None:
+        scope.reject()
+
+    def _rearm(scope: _Scope, when: float) -> None:
+        scope.update(when)
+
+
+TOTAL_TIMEOUT_HEADER: Final = "x-litellm-total-timeout"
+TOTAL_TIMEOUT_FIELD: Final = "total_timeout"
+
+
+@dataclass(frozen=True, slots=True)
+class TotalTimeout:
+    seconds: float
+    from_body: bool
+
+
+@dataclass(frozen=True, slots=True)
+class InvalidTotalTimeout:
+    message: str
+
+
+def _positive_finite_seconds(value: object) -> float | None:
+    if isinstance(value, bool) or not isinstance(value, int | float | str):
+        return None
+    try:
+        seconds: Final = float(value)
+    except (ValueError, OverflowError):
+        return None
+    return seconds if math.isfinite(seconds) and seconds > 0 else None
+
+
+def _total_timeout(value: object, *, from_body: bool) -> TotalTimeout | InvalidTotalTimeout:
+    seconds: Final = _positive_finite_seconds(value)
+    if seconds is None:
+        name: Final = TOTAL_TIMEOUT_FIELD if from_body else TOTAL_TIMEOUT_HEADER
+        return InvalidTotalTimeout(f"{name} must be a positive, finite number of seconds, got {value!r}")
+    return TotalTimeout(seconds, from_body)
+
+
+def total_timeout_from_request(
+    header: str | None, body: Mapping[str, object]
+) -> TotalTimeout | InvalidTotalTimeout | None:
+    """The request's ``total_timeout``: the header wins over the body field."""
+    if header is not None:
+        return _total_timeout(header, from_body=False)
+    if TOTAL_TIMEOUT_FIELD not in body:
+        return None
+    return _total_timeout(body[TOTAL_TIMEOUT_FIELD], from_body=True)
+
+
+def bounded_by_total_timeout(call: Mapping[str, object]) -> bool:
+    """Only a request that neither streams nor runs in the background can be bounded."""
+    return call.get("stream") is not True and call.get("background") is not True
+
+
+class TotalTimeoutNotApplicable(Exception):
+    """A request bounded by a body ``total_timeout`` streams or runs in the background."""
+
+
+class TotalTimeoutExpired(TimeoutError):
+    """The request's ``total_timeout`` ran out."""
+
+
+class TotalDeadline:
+    __slots__ = ("_at", "_clock", "_released", "_scope", "_scope_at", "from_body")
+
+    def __init__(
+        self, at: float, clock: Callable[[], float], scope: _Scope, scope_at: float, *, from_body: bool
+    ) -> None:
+        self._at: Final = at
+        self._clock: Final = clock
+        self._scope: Final = scope
+        self._scope_at: Final = scope_at
+        self._released: bool = False
+        self.from_body: Final = from_body
+
+    def expired(self) -> bool:
+        return _expired(self._scope)
+
+    def allows_wait(self, seconds: float) -> bool:
+        return self._released or self._clock() + seconds < self._at
+
+    @contextlib.contextmanager
+    def held(self) -> Generator[None, None, None]:
+        """Run the block without interrupting it; a deadline that passed meanwhile fires right after it."""
+        if self._released:
+            yield
+            return
+        _disarm(self._scope)
+        try:
+            yield
+        finally:
+            if not self._released:
+                _rearm(self._scope, self._scope_at)
+
+    def release(self) -> None:
+        self._released = True
+        if not self.expired():
+            _disarm(self._scope)
+
+
+_CURRENT: Final[ContextVar[TotalDeadline | None]] = ContextVar("total_deadline", default=None)
+
+
+def current_total_deadline() -> TotalDeadline | None:
+    return _CURRENT.get()
+
+
+@contextlib.asynccontextmanager
+async def total_timeout_held() -> AsyncGenerator[None, None]:
+    deadline: Final = _CURRENT.get()
+    if deadline is None:
+        yield
+        return
+    with deadline.held():
+        yield
+
+
+def enforce_total_timeout_scope(call: Mapping[str, object]) -> None:
+    """Raise ``TotalTimeoutNotApplicable`` for a body ``total_timeout`` on a streaming or background call,
+    and stop bounding it for a header one."""
+    deadline: Final = _CURRENT.get()
+    if deadline is None or deadline._released or bounded_by_total_timeout(call):  # pyright: ignore[reportPrivateUsage]  # same module
+        return
+    if deadline.from_body:
+        raise TotalTimeoutNotApplicable(
+            "total_timeout applies only to non-streaming, non-background requests; drop it or the stream/background flag"
+        )
+    verbose_router_logger.debug("x-litellm-total-timeout ignored: the request streams or runs in the background")
+    deadline.release()
+
+
+@contextlib.asynccontextmanager
+async def total_deadline(
+    seconds: float, *, from_body: bool, clock: Callable[[], float] | None = None
+) -> AsyncGenerator[TotalDeadline, None]:
+    """Bound the block by ``seconds``: past it the block is cancelled and ``TotalTimeoutExpired`` raised,
+    while a ``TimeoutError`` raised inside the block passes through as it was."""
+    loop: Final = asyncio.get_running_loop()
+    now: Final = clock if clock is not None else loop.time
+    scope_at: Final = loop.time() + seconds
+    scope: Final = _timeout_at(scope_at)
+    deadline: Final = TotalDeadline(now() + seconds, now, scope, scope_at, from_body=from_body)
+    try:
+        async with scope:
+            token: Final = _CURRENT.set(deadline)
+            try:
+                yield deadline
+            finally:
+                _CURRENT.reset(token)
+    except _ScopeTimeout as error:
+        if not deadline.expired():
+            raise
+        raise TotalTimeoutExpired(f"the request did not finish within its total_timeout of {seconds}s") from error
diff --git a/litellm/proxy/common_request_processing.py b/litellm/proxy/common_request_processing.py
index 887b8f98c2b..8f73d47d96b 100644
--- a/litellm/proxy/common_request_processing.py
+++ b/litellm/proxy/common_request_processing.py
@@ -174,6 +174,7 @@ _LateResponseT = TypeVar("_LateResponseT", bound=Response)
 _LlmCallT = TypeVar("_LlmCallT")
 _ResponseT: Final = TypeVar("_ResponseT")
 _ChunkT: Final = TypeVar("_ChunkT")
+_ProcessedT: Final = TypeVar("_ProcessedT")
 
 KNOWN_PROXY_ROUTES: Final = frozenset(
     route for member in LiteLLMRoutes for route in member.value if route.startswith("/")
@@ -288,6 +289,18 @@ if TYPE_CHECKING:
     ProxyConfig = _ProxyConfig
 else:
     ProxyConfig = Any
+from litellm.litellm_core_utils.total_deadline import (
+    TOTAL_TIMEOUT_FIELD,
+    TOTAL_TIMEOUT_HEADER,
+    InvalidTotalTimeout,
+    TotalTimeout,
+    TotalTimeoutExpired,
+    TotalTimeoutNotApplicable,
+    bounded_by_total_timeout,
+    current_total_deadline,
+    total_deadline,
+    total_timeout_from_request,
+)
 from litellm.proxy.anthropic_endpoints.answered_status import with_answered_status
 from litellm.proxy.anthropic_endpoints.streaming_model_restamp import (
     AnthropicStreamModelRestamper,
@@ -583,6 +596,31 @@ async def _dispatch_disconnect_billing_event(logging_obj: LiteLLMLoggingObj, par
     return True
 
 
+_TOTAL_TIMEOUT_ROUTE_TYPES: Final = frozenset({"acompletion", "aresponses", "anthropic_messages"})
+
+
+def _total_timeout_refused(message: str) -> ProxyException:
+    return ProxyException(message=message, type="invalid_request_error", param=TOTAL_TIMEOUT_FIELD, code=400)
+
+
+def _total_timeout_expired() -> bool:
+    deadline: Final = current_total_deadline()
+    return deadline is not None and deadline.expired()
+
+
+async def _cost_a_call_answered_past_its_total_timeout(
+    llm_call: "asyncio.Task[object]", logging_obj: LiteLLMLoggingObj
+) -> None:
+    """The provider answered but the request ran out of time after it (a slower moderation check): the
+    failure it is logged as still carries what the provider charged."""
+    if not llm_call.done() or llm_call.cancelled() or llm_call.exception() is not None:
+        return
+    response: Final = llm_call.result()
+    prepare_response_cost(logging_obj, response, datetime.now(timezone.utc))
+    with anyio.CancelScope(shield=True):
+        await finalize_proxy_response_cost(logging_obj, response)
+
+
 async def _cancel_pending_gather_tasks(tasks: Sequence["asyncio.Task[object]"]) -> None:
     pending_tasks: Final = [task for task in tasks if not task.done()]
     for task in pending_tasks:
@@ -3128,33 +3166,88 @@ class ProxyBaseLLMRequestProcessing:
             )
 
         return await open_sse_before_first_byte(
-            self._process_llm_request(
+            self._within_total_timeout(
                 request=request,
-                fastapi_response=fastapi_response,
-                user_api_key_dict=user_api_key_dict,
                 route_type=route_type,
-                proxy_logging_obj=proxy_logging_obj,
-                general_settings=general_settings,
-                proxy_config=proxy_config,
-                select_data_generator=select_data_generator,
-                llm_router=llm_router,
-                model=model,
-                user_model=user_model,
-                user_temperature=user_temperature,
-                user_request_timeout=user_request_timeout,
-                user_max_tokens=user_max_tokens,
-                user_api_base=user_api_base,
-                version=version,
                 is_streaming_request=is_streaming_request,
-                contents=contents,
-                skip_pre_call_logic=skip_pre_call_logic,
-                first_chunk_framing=sse_framing.first_chunk,
+                processing=self._process_llm_request(
+                    request=request,
+                    fastapi_response=fastapi_response,
+                    user_api_key_dict=user_api_key_dict,
+                    route_type=route_type,
+                    proxy_logging_obj=proxy_logging_obj,
+                    general_settings=general_settings,
+                    proxy_config=proxy_config,
+                    select_data_generator=select_data_generator,
+                    llm_router=llm_router,
+                    model=model,
+                    user_model=user_model,
+                    user_temperature=user_temperature,
+                    user_request_timeout=user_request_timeout,
+                    user_max_tokens=user_max_tokens,
+                    user_api_base=user_api_base,
+                    version=version,
+                    is_streaming_request=is_streaming_request,
+                    contents=contents,
+                    skip_pre_call_logic=skip_pre_call_logic,
+                    first_chunk_framing=sse_framing.first_chunk,
+                ),
             ),
             ping_interval_seconds=ttft_keepalive_interval(self.data, llm_router),
             on_late_failure=_audit_late_failure,
             late_framing=ANTHROPIC_LATE_SSE_FRAMING if answers_as_anthropic else sse_framing.late,
         )
 
+    def total_timeout_for(
+        self, request: Request, route_type: ProxyRouteType, is_streaming_request: bool | None
+    ) -> TotalTimeout | None:
+        """The request's ``total_timeout`` when it bounds this request: a body one on a request it cannot
+        bound is refused, a header one is ignored."""
+        body: Final = _REQUEST_FIELDS.validate_python(self.data)  # pyright: ignore[reportUnknownMemberType]  # self.data is the untyped request dict
+        header: Final = request.headers.get(TOTAL_TIMEOUT_HEADER)
+        self.data.pop(TOTAL_TIMEOUT_FIELD, None)  # pyright: ignore[reportUnknownMemberType]  # self.data is the untyped request dict
+        bounded: Final = (
+            route_type in _TOTAL_TIMEOUT_ROUTE_TYPES
+            and is_streaming_request is not True
+            and bounded_by_total_timeout(body)
+        )
+        if header is not None and not bounded:
+            verbose_proxy_logger.debug("%s ignored for this %s request", TOTAL_TIMEOUT_HEADER, route_type)
+            return None
+        parsed: Final = total_timeout_from_request(header, body)
+        if parsed is None:
+            return None
+        if isinstance(parsed, InvalidTotalTimeout):
+            raise _total_timeout_refused(parsed.message)
+        if not bounded:
+            raise _total_timeout_refused(
+                f"{TOTAL_TIMEOUT_FIELD} applies only to non-streaming, non-background "
+                "/v1/chat/completions, /v1/messages and /v1/responses requests"
+            )
+        return parsed
+
+    async def _within_total_timeout(
+        self,
+        request: Request,
+        route_type: ProxyRouteType,
+        is_streaming_request: bool | None,
+        processing: Coroutine[object, object, _ProcessedT],
+    ) -> _ProcessedT:
+        try:
+            total_timeout: Final = self.total_timeout_for(request, route_type, is_streaming_request)
+        except ProxyException:
+            processing.close()
+            raise
+        if total_timeout is None:
+            return await processing
+        try:
+            async with total_deadline(total_timeout.seconds, from_body=total_timeout.from_body):
+                return await processing
+        except TotalTimeoutExpired as expired:
+            raise ProxyException(message=str(expired), type="timeout", param=TOTAL_TIMEOUT_FIELD, code=408) from expired
+        except TotalTimeoutNotApplicable as refused:
+            raise _total_timeout_refused(str(refused)) from refused
+
     async def _process_llm_request(
         self,
         request: Request,
@@ -3238,25 +3331,32 @@ class ProxyBaseLLMRequestProcessing:
         if contents:
             self.data["contents"] = contents
 
-        ### ROUTE THE REQUEST ###
-        # Do not change this - it should be a constant time fetch - ALWAYS
-        llm_call: Final = await route_request(
-            data=self.data,
-            route_type=route_type,
-            llm_router=llm_router,
-            user_model=user_model,
-            user_api_key_dict=user_api_key_dict,
-        )
-        llm_call_task: Final = asyncio.create_task(with_proxy_compaction_executor(llm_call, request))
-        tasks.append(llm_call_task)
-
-        llm_responses: Final = asyncio.gather(*tasks)  # run the moderation check in parallel to the actual llm api call
-
         try:
-            if general_settings.get("cancel_on_disconnect", False):
-                responses = await _await_llm_call_cancelling_on_disconnect(request, llm_responses)
-            else:
-                responses = await llm_responses
+            ### ROUTE THE REQUEST ###
+            # Do not change this - it should be a constant time fetch - ALWAYS
+            llm_call: Final = await route_request(
+                data=self.data,
+                route_type=route_type,
+                llm_router=llm_router,
+                user_model=user_model,
+                user_api_key_dict=user_api_key_dict,
+            )
+            llm_call_task: Final = asyncio.create_task(with_proxy_compaction_executor(llm_call, request))
+            tasks.append(llm_call_task)
+
+            llm_responses: Final = asyncio.gather(
+                *tasks
+            )  # run the moderation check in parallel to the actual llm api call
+
+            try:
+                if general_settings.get("cancel_on_disconnect", False):
+                    responses = await _await_llm_call_cancelling_on_disconnect(request, llm_responses)
+                else:
+                    responses = await llm_responses
+            except asyncio.CancelledError:
+                if _total_timeout_expired():
+                    await _cost_a_call_answered_past_its_total_timeout(llm_call_task, logging_obj)
+                raise
         finally:
             await _cancel_pending_gather_tasks(tasks)
 
@@ -3526,7 +3626,7 @@ class ProxyBaseLLMRequestProcessing:
                             _guardrail_entries_for_headers(get_or_create_metadata_bucket(self.data)[1], logging_obj)
                         ),
                     )
-                    if isinstance(exc, asyncio.CancelledError):
+                    if isinstance(exc, asyncio.CancelledError) and not _total_timeout_expired():
                         await proxy_logging_obj.post_call_failure_hook(
                             user_api_key_dict=user_api_key_dict,
                             original_exception=HTTPException(status_code=499, detail=_CLIENT_DISCONNECT_DETAIL),
diff --git a/litellm/proxy/hooks/parallel_request_limiter_v3.py b/litellm/proxy/hooks/parallel_request_limiter_v3.py
index 6b36a6ac8bc..9fb026a64d9 100644
--- a/litellm/proxy/hooks/parallel_request_limiter_v3.py
+++ b/litellm/proxy/hooks/parallel_request_limiter_v3.py
@@ -65,6 +65,7 @@ from litellm.litellm_core_utils.token_counter import (
     offload_token_count,
     split_embedding_input_tokens,
 )
+from litellm.litellm_core_utils.total_deadline import total_timeout_held
 from litellm.llms.azure.ptu_capacity import normalized_tokens
 from litellm.proxy._types import UserAPIKeyAuth
 from litellm.proxy.auth.auth_utils import (
@@ -3801,6 +3802,7 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
                 raise cancellation
 
     @with_service_target(RATE_LIMITS_TARGET)
+    @total_timeout_held()
     async def async_pre_call_hook(
         self,
         user_api_key_dict: UserAPIKeyAuth,
diff --git a/litellm/proxy/response_api_endpoints/endpoints.py b/litellm/proxy/response_api_endpoints/endpoints.py
index 50d1c7c5b59..574a677061d 100644
--- a/litellm/proxy/response_api_endpoints/endpoints.py
+++ b/litellm/proxy/response_api_endpoints/endpoints.py
@@ -398,6 +398,9 @@ async def responses_api(
         # instead of a polling ID that immediately fails in the background task.
         processor = ProxyBaseLLMRequestProcessing(data=data)
         try:
+            # A background request runs after its polling id is returned, so a total_timeout it
+            # cannot apply is refused (or a header one dropped) before the id is handed out.
+            _ = processor.total_timeout_for(request, "aresponses", is_streaming_request=None)
             data, _logging_obj = await processor.common_processing_pre_call_logic(
                 request=request,
                 general_settings=general_settings,
diff --git a/litellm/proxy/route_llm_request.py b/litellm/proxy/route_llm_request.py
index 08942851af9..ffc0e31408d 100644
--- a/litellm/proxy/route_llm_request.py
+++ b/litellm/proxy/route_llm_request.py
@@ -17,6 +17,7 @@ import litellm
 from litellm.litellm_core_utils.core_helpers import normalize_drop_params
 from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
 from litellm.litellm_core_utils.routing_common_utils import is_proxy_admin_request
+from litellm.litellm_core_utils.total_deadline import enforce_total_timeout_scope
 from litellm.proxy._types import ProxyException, UserAPIKeyAuth
 from litellm.router import router_arguments
 from litellm.router_api import router_init_args
@@ -761,6 +762,7 @@ async def route_request(
     """
     Common helper to route the request
     """
+    enforce_total_timeout_scope(data)  # pyright: ignore[reportUnknownArgumentType]  # route_request takes an untyped dict body
     router_only_settings_from_override: Final = _merge_router_settings_override(data)  # pyright: ignore[reportUnknownArgumentType]  # route_request takes an untyped dict body
     try:
         return await _route_request_single_attempt(
diff --git a/litellm/proxy/utils.py b/litellm/proxy/utils.py
index 503dfb69793..8b9189f143f 100644
--- a/litellm/proxy/utils.py
+++ b/litellm/proxy/utils.py
@@ -188,6 +188,7 @@ from litellm.litellm_core_utils.served_output_texts import (
     served_stream_output_texts,
 )
 from litellm.litellm_core_utils.token_counter import offload_token_count, usage_tokenizer_model
+from litellm.litellm_core_utils.total_deadline import TotalTimeoutExpired
 from litellm.llms import load_guardrail_translation_mappings
 from litellm.llms.base_llm.guardrail_translation.utils import stream_item_field, stream_item_items
 from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler
@@ -1737,8 +1738,17 @@ def _client_disconnected(exception: Exception) -> bool:
     return isinstance(exception, HTTPException) and exception.status_code == LITELLM_HTTP_STATUS_CLIENT_DISCONNECTED
 
 
+def _ran_out_of_total_timeout(exception: Exception) -> bool:
+    """The request's ``total_timeout`` ran out while the provider was working on it, like a disconnect."""
+    return any(isinstance(cause, TotalTimeoutExpired) for cause in _exception_chain(exception))
+
+
 def _provider_billed_the_failure(exception: Exception) -> bool:
-    return _timed_out_reading_from_provider(exception) or _client_disconnected(exception)
+    return (
+        _timed_out_reading_from_provider(exception)
+        or _client_disconnected(exception)
+        or _ran_out_of_total_timeout(exception)
+    )
 
 
 def _as_str_mapping(value: object) -> Mapping[str, object]:
diff --git a/litellm/router_rust/core.py b/litellm/router_rust/core.py
index b7c9a96c9ff..55155a96fa3 100644
--- a/litellm/router_rust/core.py
+++ b/litellm/router_rust/core.py
@@ -69,6 +69,11 @@ from litellm.litellm_core_utils.routing_common_utils import (
 )
 from litellm.litellm_core_utils.routing_groups import validate_routing_strategy
 from litellm.litellm_core_utils.secret_redaction import redact_string
+from litellm.litellm_core_utils.total_deadline import (
+    TotalTimeoutNotApplicable,
+    current_total_deadline,
+    enforce_total_timeout_scope,
+)
 from litellm.redis.stores.connection import connect
 from litellm.redis.stores.router_cooldowns import ROUTER_COOLDOWNS_TARGET, RouterCooldownStore
 from litellm.redis.stores.router_usage import ROUTER_USAGE_TARGET, RouterUsage
@@ -2915,6 +2920,9 @@ class RustCore(
                 case "attempt":
                     outcome = await driver.attempt(step)
                 case "sleep":
+                    if (outlasted := _error_outlasting_total_timeout(driver, _sleep_seconds(step))) is not None:
+                        driver.close_route_phase()
+                        raise outlasted
                     await self._host.sleep(_sleep_seconds(step))
                     outcome = None
                 case "allow_fallback":
@@ -3873,6 +3881,15 @@ def _origin_level(origin: Mapping[str, object]) -> int:
     return level if isinstance(level, int) else 0
 
 
+def _error_outlasting_total_timeout(driver: "_Driver", seconds: float) -> BaseException | None:
+    """The error a retry would have answered when its backoff outlasts the request's total_timeout: the
+    call ends with it now, rather than with a timeout after waiting out the rest of the budget."""
+    deadline: Final = current_total_deadline()
+    if deadline is None or deadline.allows_wait(seconds):
+        return None
+    return driver.last_error
+
+
 def _sleep_seconds(step: Mapping[str, object]) -> float:
     """A retry's sleep: ``_time_to_sleep_before_retry`` returns a plain ``0`` when another
     deployment is healthy, else a backoff in float seconds."""
@@ -5198,6 +5215,7 @@ class _Driver:
             return {**self._failed(step, self._default_copy(step), None, refused_call), "recorded": True}
         try:
             deployment, call = self._call(step)  # rebind-ok: rebound as the Python router rebinds it
+            enforce_total_timeout_scope(call.kwargs)
             if call.refused is not None:
                 await log_refused_call(call, call.refused)
                 raise call.refused
@@ -5257,6 +5275,8 @@ class _Driver:
                     ATTEMPT_SETTLEMENT_GRACE_SECONDS,
                 )
             raise
+        except TotalTimeoutNotApplicable:
+            raise
         except Exception as error:  # noqa: BLE001  # every attempt failure is classified and handed to the Rust call loop
             if call is not None:
                 await released(self._release(call, attempt, refund_io_tokens=True))
diff --git a/tests/unit/litellm_core_utils/test_total_deadline.py b/tests/unit/litellm_core_utils/test_total_deadline.py
new file mode 100644
index 00000000000..f3bc99354ea
--- /dev/null
+++ b/tests/unit/litellm_core_utils/test_total_deadline.py
@@ -0,0 +1,36 @@
+from collections.abc import Mapping
+
+import pytest
+
+from litellm.litellm_core_utils.total_deadline import InvalidTotalTimeout, TotalTimeout, total_timeout_from_request
+
+
+@pytest.mark.parametrize(
+    ("header", "body", "expected"),
+    [
+        (None, {}, None),
+        (None, {"total_timeout": 10}, TotalTimeout(10.0, from_body=True)),
+        (None, {"total_timeout": "2.5"}, TotalTimeout(2.5, from_body=True)),
+        ("4", {}, TotalTimeout(4.0, from_body=False)),
+        ("4", {"total_timeout": 10}, TotalTimeout(4.0, from_body=False)),
+        ("4", {"total_timeout": "bad"}, TotalTimeout(4.0, from_body=False)),
+    ],
+    ids=["absent", "body", "body_numeric_string", "header", "header_wins", "header_wins_over_a_bad_body"],
+)
+def test_total_timeout_is_read_from_the_header_first_then_the_body(
+    header: str | None, body: Mapping[str, object], expected: TotalTimeout | None
+) -> None:
+    assert total_timeout_from_request(header, body) == expected
+
+
+@pytest.mark.parametrize(
+    "value",
+    [None, True, False, 0, -1, "0", "-2", "nan", "inf", "-inf", float("nan"), 10**400, "ten", "", [10], {"s": 10}],
+)
+def test_a_total_timeout_that_is_not_a_positive_finite_number_of_seconds_is_invalid(value: object) -> None:
+    assert isinstance(total_timeout_from_request(None, {"total_timeout": value}), InvalidTotalTimeout)
+
+
+@pytest.mark.parametrize("value", ["0", "-1", "nan", "inf", "ten", ""])
+def test_an_invalid_total_timeout_header_is_invalid(value: str) -> None:
+    assert isinstance(total_timeout_from_request(value, {}), InvalidTotalTimeout)
diff --git a/tests/unit/proxy/hooks/test_parallel_request_limiter_v3.py b/tests/unit/proxy/hooks/test_parallel_request_limiter_v3.py
index 64e7cde4034..741b6cb74b5 100644
--- a/tests/unit/proxy/hooks/test_parallel_request_limiter_v3.py
+++ b/tests/unit/proxy/hooks/test_parallel_request_limiter_v3.py
@@ -31,6 +31,7 @@ from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLogging
 from litellm.litellm_core_utils.model_latest_aliases import get_model_latest_aliases
 from litellm.litellm_core_utils.routing_common_utils import resolve_model_group_alias
 from litellm.litellm_core_utils.ptu_shares import PTUTeamCeiling
+from litellm.litellm_core_utils.total_deadline import TotalTimeoutExpired, total_deadline
 from litellm.llms.azure.ptu_capacity import AZURE_PTU_CAPACITY
 from litellm.proxy._types import UserAPIKeyAuth
 from litellm.proxy.common_utils.proxy_rate_limit_error import ProxyRateLimitError
@@ -66,6 +67,7 @@ from litellm.redis.stores.rate_limits import (
     RateLimitStore,
 )
 from litellm.responses.streaming_iterator import _record_usage_for_failure
+from tests._support.clock_loops import AutojumpClockLoop
 from tests.unit.redis.stores.fake_rate_limits import FakeRateLimits, scope_key
 from litellm.responses.utils import ResponseAPILoggingUtils
 from litellm.types.extraction import ExtractionResponse
@@ -7951,6 +7953,34 @@ async def _admit(handler, auth, data=None):
     )
 
 
+def test_a_total_timeout_never_interrupts_a_token_reservation_so_the_failure_path_can_refund_it() -> None:
+    async def reserve_outlasting_the_budget(keys: list[str], args: list[object]) -> list[object]:
+        await asyncio.sleep(120)
+        return [0, *[value for index in range(0, len(args), 4) for value in (0, args[index + 1])]]
+
+    async def admit_under_a_total_timeout() -> tuple[bool, int]:
+        redis: Final = FakeRateLimits(check_and_increment_by_n_script=reserve_outlasting_the_budget)
+        handler: Final = _handler_with_redis(redis)
+        auth: Final = UserAPIKeyAuth(api_key=hash_token("sk-total-timeout-reservation"), tpm_limit=1000)
+        stash: Final = get_or_create_request_stash()
+        try:
+            async with total_deadline(60, from_body=True):
+                await _admit(handler, auth)
+                await asyncio.sleep(3600)
+        except TotalTimeoutExpired:
+            return True, stash.reserved_tokens
+        return False, stash.reserved_tokens
+
+    loop: Final = AutojumpClockLoop()
+    try:
+        expired, reserved = loop.run_until_complete(admit_under_a_total_timeout())
+    finally:
+        loop.close()
+
+    assert expired
+    assert reserved > 0
+
+
 async def _read_only_check(handler, auth):
     descriptors = handler.create_rate_limit_descriptors(
         user_api_key_dict=auth,
diff --git a/tests/unit/proxy/search_endpoints/test_endpoints.py b/tests/unit/proxy/search_endpoints/test_endpoints.py
index 7bb4df37314..92e9076678f 100644
--- a/tests/unit/proxy/search_endpoints/test_endpoints.py
+++ b/tests/unit/proxy/search_endpoints/test_endpoints.py
@@ -142,6 +142,7 @@ def test_direct_search_body_tool_name_is_denied_under_search_tool_deny_by_defaul
 def _json_request(body: dict[str, object]) -> MagicMock:
     request = MagicMock()
     request.body = AsyncMock(return_value=orjson.dumps(body))
+    request.headers = {}
     return request
 
 
diff --git a/tests/unit/proxy/test_common_request_processing.py b/tests/unit/proxy/test_common_request_processing.py
index a519da41f61..901dbb6ea97 100644
--- a/tests/unit/proxy/test_common_request_processing.py
+++ b/tests/unit/proxy/test_common_request_processing.py
@@ -4,9 +4,9 @@ import copy
 import datetime
 import gzip
 import json
-from collections.abc import AsyncIterable, Awaitable, Mapping
+from collections.abc import AsyncIterable, Awaitable, Coroutine, Mapping
 from types import MappingProxyType, SimpleNamespace
-from typing import AsyncGenerator, Callable, Final, Iterator, Literal, Optional, Sequence
+from typing import AsyncGenerator, Callable, Final, Iterator, Literal, Optional, Sequence, TypeVar
 from urllib.parse import unquote_plus
 from unittest.mock import AsyncMock, MagicMock, patch
 
@@ -82,6 +82,7 @@ from litellm.proxy.dd_span_tagger import DDSpanTagger
 from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
 from litellm.llms.anthropic.chat.transformation import AnthropicConfig
 from litellm.proxy._types import Litellm_EntityType, ProxyErrorTypes, ProxyException
+from litellm.litellm_core_utils.total_deadline import current_total_deadline
 from litellm.proxy._types import UserAPIKeyAuth as ProxyUserAPIKeyAuth
 from litellm.proxy.auth.fallback_budget import RouterFallbackBudgetCheck
 from litellm.proxy.hooks.model_max_budget_limiter import (
@@ -11213,7 +11214,7 @@ async def test_base_process_llm_request_pings_while_the_upstream_call_is_still_r
     with patch.object(litellm, "sse_keepalive_ping_interval_seconds", 0.05):
         with patch.object(ProxyBaseLLMRequestProcessing, "_process_llm_request", slow_inner):
             response = await processor.base_process_llm_request(
-                request=MagicMock(spec=Request),
+                request=MagicMock(spec=Request, headers={}),
                 fastapi_response=Response(),
                 user_api_key_dict=MagicMock(spec=UserAPIKeyAuth),
                 route_type="acompletion",
@@ -11391,7 +11392,7 @@ async def test_base_process_llm_request_audits_a_failure_that_lands_after_its_ke
     with patch.object(litellm, "sse_keepalive_ping_interval_seconds", 0.05):
         with patch.object(ProxyBaseLLMRequestProcessing, "_process_llm_request", slow_failure):
             response = await processor.base_process_llm_request(
-                request=MagicMock(spec=Request),
+                request=MagicMock(spec=Request, headers={}),
                 fastapi_response=Response(),
                 user_api_key_dict=user_api_key_dict,
                 route_type="acompletion",
@@ -11437,7 +11438,7 @@ async def test_base_process_llm_request_honours_a_deployment_hard_disable(deploy
     with patch.object(litellm, "sse_keepalive_ping_interval_seconds", 0.05):
         with patch.object(ProxyBaseLLMRequestProcessing, "_process_llm_request", slow_inner):
             response = await processor.base_process_llm_request(
-                request=MagicMock(spec=Request),
+                request=MagicMock(spec=Request, headers={}),
                 fastapi_response=Response(),
                 user_api_key_dict=MagicMock(spec=UserAPIKeyAuth),
                 route_type="acompletion",
@@ -13321,3 +13322,343 @@ async def test_a_chained_proxy_redacts_secrets_and_internal_details_from_relayed
     assert {key: answered[key] for key in _DOWNSTREAM_GUARDRAIL_FIELDS} == dict(_DOWNSTREAM_GUARDRAIL_FIELDS)
     assert answered["scanner"]["attempts"] == 2
     assert [value for value in _DOWNSTREAM_LEAKABLE_VALUES if value in json.dumps(answered)] == []
+
+
+_ScenarioT = TypeVar("_ScenarioT")
+
+
+def _run_on_autojump_clock(scenario: Coroutine[object, object, _ScenarioT]) -> _ScenarioT:
+    loop: Final = AutojumpClockLoop()
+    try:
+        return loop.run_until_complete(scenario)
+    finally:
+        loop.run_until_complete(loop.shutdown_asyncgens())
+        loop.close()
+
+
+class TestTotalTimeout:
+    """``total_timeout`` / ``x-litellm-total-timeout`` bound a whole non-streaming request."""
+
+    def _request(self, headers: Mapping[str, str]) -> Request:
+        async def receive():
+            await asyncio.Event().wait()
+
+        return Request(
+            scope={"type": "http", "headers": [(k.encode(), v.encode()) for k, v in headers.items()]},
+            receive=receive,
+        )
+
+    async def _process(
+        self,
+        monkeypatch: pytest.MonkeyPatch,
+        llm_call: Callable[[Mapping[str, object]], object],
+        *,
+        routing: Callable[[], Awaitable[None]] | None = None,
+        body: Mapping[str, object] = MappingProxyType({}),
+        headers: Mapping[str, str] = MappingProxyType({}),
+        moderation: Callable[..., object] | None = None,
+        post_call: Callable[..., object] | None = None,
+        route_type: str = "acompletion",
+        proxy_logging_obj: MagicMock | None = None,
+        preparation: Callable[..., Awaitable[tuple[dict[str, object], MagicMock]]] | None = None,
+    ) -> tuple[object, MagicMock]:
+        from litellm.proxy._types import UserAPIKeyAuth
+
+        logging_obj: Final = MagicMock()
+        logging_obj.litellm_call_id = "total-timeout-call"
+        logging_obj.defer_async_logging = False
+        logging_obj._on_deferred_stream_complete = None
+        logging_obj.cost_breakdown = None
+        logging_obj.finalized_cost = None
+        logging_obj.prepared_cost = None
+
+        def prepared(response: object, now: object) -> object:
+            logging_obj.prepared_cost = response
+            return response
+
+        logging_obj.prepare_response_cost.side_effect = prepared
+        processor: Final = ProxyBaseLLMRequestProcessing(
+            data={"model": "fake-model", "litellm_logging_obj": logging_obj, **body}
+        )
+        hooks: Final = proxy_logging_obj if proxy_logging_obj is not None else MagicMock(spec=ProxyLogging)
+        hooks.during_call_hook = AsyncMock(side_effect=moderation, return_value=None)
+        hooks.update_request_status = AsyncMock(return_value=None)
+        hooks.post_call_success_hook = AsyncMock(
+            side_effect=post_call or (lambda data, user_api_key_dict, response: response)
+        )
+        hooks.post_call_response_headers_hook = AsyncMock(return_value=None)
+        hooks.post_call_failure_hook = AsyncMock(return_value=None)
+
+        async def fake_route_request(**kwargs):
+            if routing is not None:
+                await routing()
+            return llm_call(kwargs["data"])
+
+        monkeypatch.setattr(litellm.proxy.common_request_processing, "route_request", fake_route_request)
+        if preparation is not None:
+            monkeypatch.setattr(processor, "_pre_call_with_fallbacks", preparation)
+        result: Final = await processor.base_process_llm_request(
+            request=self._request(headers),
+            fastapi_response=Response(),
+            user_api_key_dict=UserAPIKeyAuth(api_key="sk-test"),
+            route_type=route_type,
+            proxy_logging_obj=hooks,
+            general_settings={},
+            proxy_config=MagicMock(spec=ProxyConfig),
+            skip_pre_call_logic=preparation is None,
+        )
+        return result, logging_obj
+
+    @pytest.mark.parametrize(
+        ("body", "headers"),
+        [({"total_timeout": 60}, {}), ({}, {"x-litellm-total-timeout": "60"})],
+        ids=["body", "header"],
+    )
+    def test_a_request_past_its_total_timeout_is_answered_with_a_408_and_its_call_is_cancelled(
+        self, monkeypatch: pytest.MonkeyPatch, body: Mapping[str, object], headers: Mapping[str, str]
+    ) -> None:
+        async def provider_hangs_past_the_budget() -> tuple[ProxyException, bool]:
+            provider_called: Final = asyncio.Event()
+            upstream_cancelled: Final = asyncio.Event()
+
+            async def hanging(_: Mapping[str, object]) -> object:
+                provider_called.set()
+                try:
+                    await asyncio.Event().wait()
+                except asyncio.CancelledError:
+                    upstream_cancelled.set()
+                    raise
+                raise AssertionError
+
+            processing: Final = asyncio.create_task(self._process(monkeypatch, hanging, body=body, headers=headers))
+            await provider_called.wait()
+            with pytest.raises(ProxyException) as raised:
+                await processing
+            return raised.value, upstream_cancelled.is_set()
+
+        expired, upstream_cancelled = _run_on_autojump_clock(provider_hangs_past_the_budget())
+
+        assert expired.code == "408"
+        assert expired.param == "total_timeout"
+        assert upstream_cancelled
+
+    def test_a_moderation_check_outlasting_the_budget_after_the_provider_answered_prepares_its_cost(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        answer: Final = litellm.ModelResponse()
+
+        async def moderation_outlasts_the_budget() -> tuple[ProxyException, MagicMock]:
+            answered: Final = asyncio.Event()
+            moderating: Final = asyncio.Event()
+            logging_objs: Final[list[MagicMock]] = []
+
+            async def provider(data: Mapping[str, object]) -> object:
+                logging_objs.append(data["litellm_logging_obj"])  # pyright: ignore[reportArgumentType]  # the harness's logging double
+                answered.set()
+                return answer
+
+            async def slow_moderation(**_: object) -> None:
+                moderating.set()
+                await asyncio.Event().wait()
+
+            processing: Final = asyncio.create_task(
+                self._process(monkeypatch, provider, body={"total_timeout": 60}, moderation=slow_moderation)
+            )
+            await answered.wait()
+            await moderating.wait()
+            with pytest.raises(ProxyException) as raised:
+                await processing
+            return raised.value, logging_objs[0]
+
+        expired, logging_obj = _run_on_autojump_clock(moderation_outlasts_the_budget())
+
+        costed: Final = [call.args[0] for call in logging_obj.prepare_response_cost.call_args_list]
+        assert expired.code == "408"
+        assert costed
+        assert all(response is answer for response in costed)
+
+    async def test_a_provider_timeout_inside_the_budget_is_not_turned_into_a_408(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        async def provider_timed_out(_: Mapping[str, object]) -> object:
+            raise TimeoutError("provider read timeout")
+
+        with pytest.raises(TimeoutError, match="provider read timeout"):
+            await self._process(monkeypatch, provider_timed_out, body={"total_timeout": 60})
+
+    async def test_cancelling_a_request_inside_its_budget_still_cancels_it(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        provider_called: Final = asyncio.Event()
+
+        async def hanging(_: Mapping[str, object]) -> object:
+            provider_called.set()
+            await asyncio.Event().wait()
+            raise AssertionError
+
+        processing: Final = asyncio.create_task(self._process(monkeypatch, hanging, body={"total_timeout": 60}))
+        await provider_called.wait()
+        processing.cancel()
+
+        with pytest.raises(asyncio.CancelledError):
+            await processing
+
+    async def test_a_bounded_request_reaches_the_router_bounded_and_without_its_total_timeout_field(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        seen: Final[list[tuple[bool, bool]]] = []
+
+        async def answered(data: Mapping[str, object]) -> object:
+            seen.append(("total_timeout" in data, current_total_deadline() is not None))
+            return litellm.ModelResponse()
+
+        await self._process(monkeypatch, answered, body={"total_timeout": 60})
+
+        assert seen == [(False, True)]
+
+    @pytest.mark.parametrize(
+        ("body", "route_type"),
+        [
+            ({"total_timeout": 60, "stream": True}, "acompletion"),
+            ({"total_timeout": 60, "background": True}, "aresponses"),
+            ({"total_timeout": 60}, "aembedding"),
+            ({"total_timeout": 0}, "acompletion"),
+            ({"total_timeout": None}, "acompletion"),
+        ],
+        ids=["streaming", "background_responses", "other_route", "zero", "null"],
+    )
+    async def test_a_body_total_timeout_it_cannot_apply_is_refused_before_the_call(
+        self, monkeypatch: pytest.MonkeyPatch, body: Mapping[str, object], route_type: str
+    ) -> None:
+        called: Final[list[object]] = []
+
+        async def answered(data: Mapping[str, object]) -> object:
+            called.append(data)
+            return litellm.ModelResponse()
+
+        with pytest.raises(ProxyException) as raised:
+            await self._process(monkeypatch, answered, body=body, route_type=route_type)
+
+        assert raised.value.code == "400"
+        assert raised.value.param == "total_timeout"
+        assert called == []
+
+    @pytest.mark.parametrize("header", ["60", "10s", "", "0"], ids=["valid", "with_a_unit", "empty", "zero"])
+    @pytest.mark.parametrize(
+        ("body", "route_type"),
+        [({"stream": True}, "acompletion"), ({"background": True}, "aresponses"), ({}, "aembedding")],
+        ids=["streaming", "background_responses", "other_route"],
+    )
+    async def test_a_header_total_timeout_leaves_a_request_it_cannot_apply_unbounded_whatever_its_value(
+        self, monkeypatch: pytest.MonkeyPatch, body: Mapping[str, object], route_type: str, header: str
+    ) -> None:
+        bounded: Final[list[bool]] = []
+
+        async def answered(_: Mapping[str, object]) -> object:
+            bounded.append(current_total_deadline() is not None)
+            return litellm.ModelResponse()
+
+        await self._process(
+            monkeypatch, answered, body=body, headers={"x-litellm-total-timeout": header}, route_type=route_type
+        )
+
+        assert bounded == [False]
+
+    def test_a_post_call_hook_outlasting_the_budget_is_a_408_not_a_client_disconnect(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        hooks: Final = MagicMock(spec=ProxyLogging)
+
+        async def guardrail_outlasts_the_budget() -> ProxyException:
+            guarding: Final = asyncio.Event()
+
+            async def answered(_: Mapping[str, object]) -> object:
+                return litellm.ModelResponse()
+
+            async def slow_guardrail(**_: object) -> object:
+                guarding.set()
+                await asyncio.Event().wait()
+                raise AssertionError
+
+            processing: Final = asyncio.create_task(
+                self._process(
+                    monkeypatch, answered, body={"total_timeout": 60}, post_call=slow_guardrail, proxy_logging_obj=hooks
+                )
+            )
+            await guarding.wait()
+            with pytest.raises(ProxyException) as raised:
+                await processing
+            return raised.value
+
+        expired: Final = _run_on_autojump_clock(guardrail_outlasts_the_budget())
+
+        assert expired.code == "408"
+        hooks.post_call_failure_hook.assert_not_awaited()
+
+    def test_a_budget_that_runs_out_while_routing_also_stops_the_moderation_check(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        async def routing_outlasts_the_budget() -> tuple[ProxyException, bool]:
+            moderating: Final = asyncio.Event()
+            routing: Final = asyncio.Event()
+            moderation_stopped: Final = asyncio.Event()
+
+            async def moderation(**_: object) -> None:
+                moderating.set()
+                try:
+                    await asyncio.Event().wait()
+                except asyncio.CancelledError:
+                    moderation_stopped.set()
+                    raise
+
+            async def stuck_routing() -> None:
+                routing.set()
+                await asyncio.Event().wait()
+
+            async def never_called(_: Mapping[str, object]) -> object:
+                raise AssertionError
+
+            processing: Final = asyncio.create_task(
+                self._process(
+                    monkeypatch, never_called, routing=stuck_routing, body={"total_timeout": 60}, moderation=moderation
+                )
+            )
+            await moderating.wait()
+            await routing.wait()
+            with pytest.raises(ProxyException) as raised:
+                await processing
+            return raised.value, moderation_stopped.is_set()
+
+        expired, moderation_stopped = _run_on_autojump_clock(routing_outlasts_the_budget())
+
+        assert expired.code == "408"
+        assert moderation_stopped
+
+    def test_a_budget_that_runs_out_while_preparing_cuts_preparation_short_and_never_calls_the_provider(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        async def preparation_outlasts_the_budget() -> tuple[ProxyException, bool, bool, float]:
+            loop: Final = asyncio.get_running_loop()
+            started: Final = loop.time()
+            prepared: Final = asyncio.Event()
+            called: Final = asyncio.Event()
+
+            async def slow_guardrail(**_: object) -> tuple[dict[str, object], MagicMock]:
+                await asyncio.sleep(120)
+                prepared.set()
+                return {"model": "fake-model"}, MagicMock()
+
+            async def provider(_: Mapping[str, object]) -> object:
+                called.set()
+                return litellm.ModelResponse()
+
+            with pytest.raises(ProxyException) as raised:
+                await self._process(monkeypatch, provider, body={"total_timeout": 60}, preparation=slow_guardrail)
+            return raised.value, prepared.is_set(), called.is_set(), loop.time() - started
+
+        expired, prepared, called, elapsed = _run_on_autojump_clock(preparation_outlasts_the_budget())
+
+        assert expired.code == "408"
+        assert not prepared
+        assert not called
+        assert elapsed < 120
diff --git a/tests/unit/proxy/test_litellm_pre_call_utils.py b/tests/unit/proxy/test_litellm_pre_call_utils.py
index 97c21fcc777..af463fa19d4 100644
--- a/tests/unit/proxy/test_litellm_pre_call_utils.py
+++ b/tests/unit/proxy/test_litellm_pre_call_utils.py
@@ -17,8 +17,6 @@ from pydantic import ValidationError as PydanticValidationError
 from starlette.datastructures import Headers
 
 import litellm
-from litellm.proxy.common_utils.user_api_key_cache import UserApiKeyCache
-from tests.unit.proxy.router_entry_point_stubs import route_entry_points_to_stubs
 from litellm.constants import (
     CALLER_SESSION_ID_METADATA_KEY,
     COMPLEXITY_ROUTER_CHILD_SESSION_ID_METADATA_KEY,
@@ -40,6 +38,7 @@ from litellm.litellm_core_utils.redact_messages import _get_turn_off_message_log
 from litellm.llms.bedrock.base_aws_llm import BaseAWSLLM
 from litellm.llms.fireworks_ai.common_utils import get_fireworks_session_id
 from litellm.proxy._types import AddTeamCallback, ProxyException, TeamCallbackMetadata, UserAPIKeyAuth
+from litellm.proxy.common_utils.user_api_key_cache import UserApiKeyCache
 from litellm.proxy.litellm_pre_call_utils import (
     KeyAndTeamLoggingSettings,
     LiteLLMProxyRequestSetup,
@@ -64,6 +63,7 @@ from litellm.proxy.litellm_pre_call_utils import (
 from litellm.proxy.spend_tracking.spend_tracking_utils import get_logging_payload
 from litellm.types.litellm_params import AGENTIC_LOOP_KWARG_NAMES
 from litellm.types.utils import CredentialItem
+from tests.unit.proxy.router_entry_point_stubs import route_entry_points_to_stubs
 
 
 def test_check_if_token_is_service_account():
@@ -112,7 +112,8 @@ class TestGetMetadataVariableName:
         assert get_metadata_variable_name(request) == "litellm_metadata"
 
     @pytest.mark.parametrize(
-        "path", ["/v1beta/interactions", "/interactions", "/v1beta/interactions/v1_abc123", "/interactions/v1_abc123/cancel"]
+        "path",
+        ["/v1beta/interactions", "/interactions", "/v1beta/interactions/v1_abc123", "/interactions/v1_abc123/cancel"],
     )
     def test_returns_litellm_metadata_for_interactions_routes(self, path):
         request = self._make_request(path)
@@ -808,7 +809,9 @@ async def test_interactions_spend_logs_metadata_survives_the_router_metadata_buc
 
     # The router then adds its deployment fields to the same bucket, and the spend log
     # resolves that bucket.
-    data["litellm_metadata"].update({"model_group": "gemini-3.1-flash-lite", "deployment": "gemini/gemini-3.1-flash-lite"})
+    data["litellm_metadata"].update(
+        {"model_group": "gemini-3.1-flash-lite", "deployment": "gemini/gemini-3.1-flash-lite"}
+    )
     resolved = get_litellm_metadata_from_kwargs(
         {"litellm_params": {"metadata": data.get("metadata") or {}, "litellm_metadata": data["litellm_metadata"]}}
     )
@@ -3759,53 +3762,87 @@ async def test_spend_log_caller_session_stays_out_of_requester_metadata(monkeypa
     "surface,headers,body,child_id,trace_id",
     [
         (
-            "chat/completions", {"X-Session-Id": "child-01"}, {"metadata": {"session_id": "body-001"}},
-            "child-01", "parent-01",
+            "chat/completions",
+            {"X-Session-Id": "child-01"},
+            {"metadata": {"session_id": "body-001"}},
+            "child-01",
+            "parent-01",
         ),
         ("responses", {"x-vendor-session-id": "child-01"}, {}, "child-01", "parent-01"),
         ("messages", {"session-id": "child-01", "user-agent": "codex_cli_rs/1.0"}, {}, "child-01", "parent-01"),
         ("chat/completions", {"x-litellm-session-id": "short", "x-session-id": "child-01"}, {}, "short", "short"),
         ("responses", {"x-litellm-trace-id": "trace-01", "x-session-id": "child-01"}, {}, "child-01", "trace-01"),
         (
-            "messages", {"x-litellm-trace-id": "trace-01", "x-litellm-session-id": "child-01"},
-            {}, "child-01", "trace-01",
+            "messages",
+            {"x-litellm-trace-id": "trace-01", "x-litellm-session-id": "child-01"},
+            {},
+            "child-01",
+            "trace-01",
         ),
         ("responses", {}, {"metadata": {"session_id": "body-001"}}, "body-001", "parent-01"),
         ("messages", {}, {"litellm_metadata": {"session_id": "body-001"}}, "body-001", "parent-01"),
         ("chat/completions", {}, {"litellm_metadata": {"session_id": "body-001"}}, "body-001", "parent-01"),
         ("messages", {"baggage": "session.id=child-01"}, {}, "child-01", "parent-01"),
         (
-            "responses", {"baggage": "session.id=child-01"}, {"metadata": {"session_id": "body-001"}},
-            "body-001", "parent-01",
+            "responses",
+            {"baggage": "session.id=child-01"},
+            {"metadata": {"session_id": "body-001"}},
+            "body-001",
+            "parent-01",
         ),
         (
-            "chat/completions", {}, {"litellm_session_id": "root-001", "metadata": {"session_id": "body-001"}},
-            "root-001", "parent-01",
+            "chat/completions",
+            {},
+            {"litellm_session_id": "root-001", "metadata": {"session_id": "body-001"}},
+            "root-001",
+            "parent-01",
         ),
         (
-            "responses", {}, {"metadata": {"session_id": "body-001"}, "litellm_metadata": {"session_id": "active-1"}},
-            "active-1", "parent-01",
+            "responses",
+            {},
+            {"metadata": {"session_id": "body-001"}, "litellm_metadata": {"session_id": "active-1"}},
+            "active-1",
+            "parent-01",
         ),
         (
-            "chat/completions", {},
+            "chat/completions",
+            {},
             {"metadata": {"session_id": "active-1"}, "litellm_metadata": {"session_id": "body-001"}},
-            "active-1", "parent-01",
+            "active-1",
+            "parent-01",
         ),
         (
-            "chat/completions", {}, {"metadata": {"session_id": ""}, "litellm_metadata": {"session_id": "body-001"}},
-            None, "parent-01",
+            "chat/completions",
+            {},
+            {"metadata": {"session_id": ""}, "litellm_metadata": {"session_id": "body-001"}},
+            None,
+            "parent-01",
         ),
         (
-            "messages", {}, {"metadata": {"session_id": "body-001"}, "litellm_metadata": {"session_id": ""}},
-            None, "parent-01",
+            "messages",
+            {},
+            {"metadata": {"session_id": "body-001"}, "litellm_metadata": {"session_id": ""}},
+            None,
+            "parent-01",
         ),
         (
-            "messages", {}, {"litellm_session_id": "root-001", "litellm_metadata": {"session_id": "active-1"},
-            "metadata": {"session_id": "body-001", "user_id": "user_abc_account__session_anthro-1"}},
-            "anthro-1", "parent-01",
+            "messages",
+            {},
+            {
+                "litellm_session_id": "root-001",
+                "litellm_metadata": {"session_id": "active-1"},
+                "metadata": {"session_id": "body-001", "user_id": "user_abc_account__session_anthro-1"},
+            },
+            "anthro-1",
+            "parent-01",
+        ),
+        (
+            "messages",
+            {"x-session-id": "child-01"},
+            {"metadata": {"user_id": {"session_id": "body-001"}}},
+            "child-01",
+            "parent-01",
         ),
-        ("messages", {"x-session-id": "child-01"}, {"metadata": {"user_id": {"session_id": "body-001"}}},
-         "child-01", "parent-01"),
         ("chat/completions", {}, {}, None, "parent-01"),
         ("responses", {"x-session-id": "bad"}, {}, None, "parent-01"),
         ("messages", {}, {"metadata": {"session_id": 123}}, None, "parent-01"),
@@ -4347,9 +4384,7 @@ def _bedrock_passthrough_data(
         ),
     ],
 )
-def test_bedrock_request_metadata_thread_id_becomes_session_id(
-    headers: dict[str, str], client_body: dict[str, object]
-):
+def test_bedrock_request_metadata_thread_id_becomes_session_id(headers: dict[str, str], client_body: dict[str, object]):
     sent_body: Final = copy.deepcopy(client_body)
     data: Final = _bedrock_passthrough_data(client_body)
 
@@ -4429,7 +4464,9 @@ def test_bedrock_request_metadata_without_usable_session_id_sets_no_session(
 @pytest.mark.parametrize(
     ("body_tags", "header_tags", "expected"),
     [
-        pytest.param({"team": "search"}, {"threadId": "thread-abc-123"}, "thread-abc-123", id="body_without_session_key"),
+        pytest.param(
+            {"team": "search"}, {"threadId": "thread-abc-123"}, "thread-abc-123", id="body_without_session_key"
+        ),
         pytest.param({"sessionId": "body-session"}, {"sessionId": "header-session"}, "body-session", id="body_wins"),
     ],
 )
@@ -11226,9 +11263,7 @@ async def test_header_mapped_user_id_cannot_load_another_users_connection(monkey
     from litellm.proxy.litellm_pre_call_utils import add_litellm_data_to_request
 
     _per_user_env(monkeypatch)
-    load = AsyncMock(
-        return_value={"copilot-cred": {"access_token": "gho_user_a_token", "github_host": "github.com"}}
-    )
+    load = AsyncMock(return_value={"copilot-cred": {"access_token": "gho_user_a_token", "github_host": "github.com"}})
     monkeypatch.setattr(upc, "aget_user_provider_credentials", load)
     router = Router(
         model_list=[
@@ -11281,9 +11316,7 @@ async def test_per_user_token_resolution_uses_key_identity_without_header_mappin
     from litellm.proxy.litellm_pre_call_utils import add_litellm_data_to_request
 
     _per_user_env(monkeypatch)
-    load = AsyncMock(
-        return_value={"copilot-cred": {"access_token": "gho_user_a_token", "github_host": "github.com"}}
-    )
+    load = AsyncMock(return_value={"copilot-cred": {"access_token": "gho_user_a_token", "github_host": "github.com"}})
     monkeypatch.setattr(upc, "aget_user_provider_credentials", load)
     router = Router(
         model_list=[
diff --git a/tests/unit/proxy/test_proxy_utils_model_creation_and_error_logging.py b/tests/unit/proxy/test_proxy_utils_model_creation_and_error_logging.py
index f74ff9b1fca..867259a9b3b 100644
--- a/tests/unit/proxy/test_proxy_utils_model_creation_and_error_logging.py
+++ b/tests/unit/proxy/test_proxy_utils_model_creation_and_error_logging.py
@@ -561,7 +561,11 @@ class TestPostCallFailureHookDoesNotInventAProviderHandoff:
             litellm_call_id="pre-handoff-auth-failure",
             function_id="pre-handoff",
         )
-        request_data: Final[dict[str, object]] = {"litellm_logging_obj": logging_obj, "model": "gpt-4.1", "metadata": {}}
+        request_data: Final[dict[str, object]] = {
+            "litellm_logging_obj": logging_obj,
+            "model": "gpt-4.1",
+            "metadata": {},
+        }
         proxy_logging_obj = ProxyLogging(user_api_key_cache=DualCache())
         proxy_logging_obj.alert_types = []
         with (
@@ -1116,6 +1120,44 @@ class TestPostCallFailureHookEstimatesDispatchedInputTokens:
         assert expected_input_cost > 0
         assert request_data["response_cost"] == pytest.approx(expected_input_cost)
 
+    @pytest.mark.asyncio
+    async def test_a_total_timeout_that_ran_out_after_dispatch_is_priced_at_input_rate(self):
+        from datetime import datetime
+
+        from litellm.litellm_core_utils.total_deadline import TotalTimeoutExpired
+        from litellm.proxy._types import ProxyException
+        from litellm.types.utils import Usage
+
+        def ran_out() -> ProxyException:
+            try:
+                raise TotalTimeoutExpired("the request did not finish within its total_timeout of 2.0s")
+            except TotalTimeoutExpired as expired:
+                try:
+                    raise ProxyException(
+                        message=str(expired), type="timeout", param="total_timeout", code=408
+                    ) from expired
+                except ProxyException as answered:
+                    return answered
+
+        request_data = {
+            "litellm_logging_obj": self._logging_obj(
+                {
+                    "first_api_call_start_time": datetime.now(),
+                    "model": "gpt-3.5-turbo",
+                    "messages": [{"role": "user", "content": "count these input tokens please"}],
+                    "call_type": "acompletion",
+                }
+            ),
+            "metadata": {},
+        }
+        await self._run(request_data, original_exception=ran_out())
+
+        estimated = request_data["combined_usage_object"]
+        assert isinstance(estimated, Usage)
+        expected_input_cost, _ = litellm.cost_per_token(model="gpt-3.5-turbo", prompt_tokens=estimated.prompt_tokens)
+        assert expected_input_cost > 0
+        assert request_data["response_cost"] == pytest.approx(expected_input_cost)
+
     @pytest.mark.asyncio
     async def test_upstream_499_error_is_a_plain_failure_not_a_priced_disconnect(self):
         """A provider answering HTTP 499 surfaces as litellm.APIError with status_code 499. Only the
@@ -2693,7 +2735,12 @@ def test_an_earlier_attempt_on_another_model_is_priced_at_that_models_rate_not_t
         monkeypatch.setitem(
             litellm.model_cost,
             pricing_model,
-            {"litellm_provider": provider, "mode": "chat", "input_cost_per_token": input_rate, "output_cost_per_token": 1.0},
+            {
+                "litellm_provider": provider,
+                "mode": "chat",
+                "input_cost_per_token": input_rate,
+                "output_cost_per_token": 1.0,
+            },
         )
     usage = litellm.Usage(prompt_tokens=24, completion_tokens=0, total_tokens=24)
 
@@ -2926,9 +2973,7 @@ async def test_dropped_stream_failure_attribution_reaches_terminal_spend_row() -
     request_data: Final = {"litellm_logging_obj": logging_obj}
     lifted: Final = _failure_fields_to_lift(request_data, provider_billed=True)
     terminal_kwargs: Final = {
-        key: value
-        for key, value in {**request_data, **lifted}.items()
-        if key != "litellm_logging_obj"
+        key: value for key, value in {**request_data, **lifted}.items() if key != "litellm_logging_obj"
     }
     row: Final = get_logging_payload(
         kwargs=terminal_kwargs,
@@ -3101,9 +3146,7 @@ async def test_latest_dropped_attempt_publishes_its_payload_after_earlier_dispat
     request_data: Final = {"litellm_logging_obj": logging_obj}
     lifted: Final = _failure_fields_to_lift(request_data, provider_billed=True)
     terminal_kwargs: Final = {
-        key: value
-        for key, value in {**request_data, **lifted}.items()
-        if key != "litellm_logging_obj"
+        key: value for key, value in {**request_data, **lifted}.items() if key != "litellm_logging_obj"
     }
     row: Final = get_logging_payload(
         kwargs=terminal_kwargs,
@@ -3158,9 +3201,7 @@ async def test_dropped_attempt_attribution_is_published_while_failure_callback_i
     request_data: Final = {"litellm_logging_obj": logging_obj}
     lifted: Final = _failure_fields_to_lift(request_data, provider_billed=True)
     terminal_kwargs: Final = {
-        key: value
-        for key, value in {**request_data, **lifted}.items()
-        if key != "litellm_logging_obj"
+        key: value for key, value in {**request_data, **lifted}.items() if key != "litellm_logging_obj"
     }
     row: Final = get_logging_payload(
         kwargs=terminal_kwargs,
@@ -3237,9 +3278,7 @@ async def test_failed_attempt_publishes_baseline_reason_after_invalidation(
         request_data: Final = {"litellm_logging_obj": logging_obj}
         lifted: Final = _failure_fields_to_lift(request_data, provider_billed=True)
         terminal_kwargs: Final = {
-            key: value
-            for key, value in {**request_data, **lifted}.items()
-            if key != "litellm_logging_obj"
+            key: value for key, value in {**request_data, **lifted}.items() if key != "litellm_logging_obj"
         }
         row: Final = get_logging_payload(
             kwargs=terminal_kwargs,
@@ -3254,9 +3293,7 @@ async def test_failed_attempt_publishes_baseline_reason_after_invalidation(
         assert row["prompt_tokens"] == 4
         assert row["completion_tokens"] == 1
         lifted_payload: Final = TypeAdapter(StandardLoggingPayload).validate_python(lifted["standard_logging_object"])
-        callback_payload: Final = TypeAdapter(StandardLoggingPayload).validate_python(
-            recorder.standard_logging_object
-        )
+        callback_payload: Final = TypeAdapter(StandardLoggingPayload).validate_python(recorder.standard_logging_object)
 
         def baseline_reason(payload: StandardLoggingPayload) -> str:
             encoded: Final = payload["autorouter_baseline_observation"]
@@ -3335,9 +3372,7 @@ async def test_queued_stale_attempt_dispatch_does_not_publish_over_current_attem
         request_data: Final = {"litellm_logging_obj": logging_obj}
         lifted: Final = _failure_fields_to_lift(request_data, provider_billed=True)
         terminal_kwargs: Final = {
-            key: value
-            for key, value in {**request_data, **lifted}.items()
-            if key != "litellm_logging_obj"
+            key: value for key, value in {**request_data, **lifted}.items() if key != "litellm_logging_obj"
         }
         row: Final = get_logging_payload(
             kwargs=terminal_kwargs,
@@ -3402,9 +3437,7 @@ async def test_dropped_stream_failure_does_not_overwrite_newer_terminal_payload(
         request_data: Final = {"litellm_logging_obj": logging_obj}
         lifted: Final = _failure_fields_to_lift(request_data, provider_billed=True)
         terminal_kwargs: Final = {
-            key: value
-            for key, value in {**request_data, **lifted}.items()
-            if key != "litellm_logging_obj"
+            key: value for key, value in {**request_data, **lifted}.items() if key != "litellm_logging_obj"
         }
         row: Final = get_logging_payload(
             kwargs=terminal_kwargs,
@@ -3658,7 +3691,6 @@ def test_a_request_that_timed_out_at_a_provider_bills_its_input_at_the_input_rat
     assert response_cost == pytest.approx(expected_input_cost)
 
 
-
 COMPACTION_INSTRUCTIONS = {"role": "system", "content": "answer briefly"}
 COMPACTED_HISTORY = [
     {"role": "user", "content": "a long turn " * 200},
@@ -3735,8 +3767,6 @@ def test_an_earlier_timed_out_responses_attempt_counts_its_input_from_the_newest
     assert sent == earlier_attempt_prompt_tokens([COMPACTION_INSTRUCTIONS, COMPACTION_ITEM, TURN_AFTER_COMPACTION])
 
 
-
-
 @pytest.mark.parametrize(
     "current_attempt_api_call_start_time",
     [None, 1700000001.0],
@@ -4076,9 +4106,7 @@ def test_create_model_info_response_resolves_mode_through_deployment_model():
             ]
         )
 
-        response = create_model_info_response(
-            model_id="my-embeddings", provider="openai", llm_router=router
-        )
+        response = create_model_info_response(model_id="my-embeddings", provider="openai", llm_router=router)
     finally:
         litellm.model_cost.clear()
         litellm.model_cost.update(saved_model_cost)
@@ -4108,12 +4136,8 @@ def test_create_model_info_response_resolves_model_group_alias_to_target(model_g
         model_group_alias=model_group_alias,
     )
 
-    alias_response = create_model_info_response(
-        model_id="team-embeddings", provider="openai", llm_router=router
-    )
-    target_response = create_model_info_response(
-        model_id="my-embeddings", provider="openai", llm_router=router
-    )
+    alias_response = create_model_info_response(model_id="team-embeddings", provider="openai", llm_router=router)
+    target_response = create_model_info_response(model_id="my-embeddings", provider="openai", llm_router=router)
 
     assert alias_response["id"] == "team-embeddings"
     for field in ("mode", "max_input_tokens", "max_output_tokens"):
@@ -4196,7 +4220,9 @@ async def test_post_call_failure_hook_redacts_traceback_before_callbacks(monkeyp
     with patch.object(proxy_logging_obj, "update_request_status", new=AsyncMock()):
         await proxy_logging_obj.post_call_failure_hook(
             request_data={"metadata": {}},
-            original_exception=HTTPException(status_code=400, detail="Upstream passthrough request failed with status 400"),
+            original_exception=HTTPException(
+                status_code=400, detail="Upstream passthrough request failed with status 400"
+            ),
             user_api_key_dict=UserAPIKeyAuth(),
             traceback_str=upstream_traceback,
         )
@@ -4260,9 +4286,13 @@ def test_mcp_conversion_preserves_request_policy_and_isolates_guardrail_data(buc
     parent = {
         "model": "parent-model",
         bucket: {
-            "guardrails": ["policy-rule"], "guardrail_config": {"language": "en"},
-            "applied_policies": ["parent-policy"], "policy_sources": {"parent-policy": "model"},
-            "_guardrail_pipelines": [], "_pipeline_managed_guardrails": ["pipeline-rule"], "tags": ["review"],
+            "guardrails": ["policy-rule"],
+            "guardrail_config": {"language": "en"},
+            "applied_policies": ["parent-policy"],
+            "policy_sources": {"parent-policy": "model"},
+            "_guardrail_pipelines": [],
+            "_pipeline_managed_guardrails": ["pipeline-rule"],
+            "tags": ["review"],
         },
         "guardrails": [{"request-rule": {"extra_body": {"threshold": 0.9}}}],
         "guardrail_config": {"entities": ["EMAIL_ADDRESS"]},
@@ -4292,13 +4322,26 @@ def test_mcp_conversion_honors_only_authenticated_global_guardrail_opt_outs(opt_
     from litellm.responses.mcp.request_context import MCPRequestContext
 
     auth = UserAPIKeyAuth(metadata={"opted_out_global_guardrails": ["global-rule"] if opt_out else []})
-    context = MCPRequestContext.resolve(kwargs={"metadata": {
-        "user_api_key_auth": auth, "disable_global_guardrails": True,
-        "user_api_key_metadata": {"disable_global_guardrails": True},
-    }}, tools=None)
+    context = MCPRequestContext.resolve(
+        kwargs={
+            "metadata": {
+                "user_api_key_auth": auth,
+                "disable_global_guardrails": True,
+                "user_api_key_metadata": {"disable_global_guardrails": True},
+            }
+        },
+        tools=None,
+    )
     proxy_logging = ProxyLogging(user_api_key_cache=DualCache())
-    kwargs = {"name": "execute", "arguments": {}, "user_api_key_auth": auth, "guardrail_context": context.guardrail_context}
-    synthetic = proxy_logging._convert_mcp_to_llm_format(proxy_logging._create_mcp_request_object_from_kwargs(kwargs), kwargs)
+    kwargs = {
+        "name": "execute",
+        "arguments": {},
+        "user_api_key_auth": auth,
+        "guardrail_context": context.guardrail_context,
+    }
+    synthetic = proxy_logging._convert_mcp_to_llm_format(
+        proxy_logging._create_mcp_request_object_from_kwargs(kwargs), kwargs
+    )
     guardrail = CustomGuardrail(guardrail_name="global-rule", event_hook="pre_mcp_call", default_on=True)
     assert guardrail.should_run_guardrail(synthetic, GuardrailEventHooks.pre_mcp_call) is (not opt_out)
     synthetic["metadata"]["user_api_key_metadata"]["opted_out_global_guardrails"].append("unrelated")
@@ -4312,19 +4355,26 @@ def test_mcp_auth_policy_uses_original_request_model(monkeypatch, model, expecte
     from litellm.types.proxy.policy_engine import Policy, PolicyCondition, PolicyGuardrails
 
     registry = policy_registry.PolicyRegistry()
-    registry._policies = {"model-policy": Policy(
-        condition=PolicyCondition(model="parent-model"), guardrails=PolicyGuardrails(add=["model-rule"])
-    )}
+    registry._policies = {
+        "model-policy": Policy(
+            condition=PolicyCondition(model="parent-model"), guardrails=PolicyGuardrails(add=["model-rule"])
+        )
+    }
     registry._initialized = True
     monkeypatch.setattr(policy_registry, "_policy_registry", registry)
     monkeypatch.setattr("litellm.proxy.proxy_server.premium_user", True)
     proxy_logging = ProxyLogging(user_api_key_cache=DualCache())
     kwargs = {
-        "name": "execute", "arguments": {},
+        "name": "execute",
+        "arguments": {},
         "user_api_key_auth": UserAPIKeyAuth(metadata={"policies": ["model-policy"]}),
-        "guardrail_context": MCPRequestContext.resolve_guardrail_context({"model": model, "guardrails": ["request-rule"]}),
+        "guardrail_context": MCPRequestContext.resolve_guardrail_context(
+            {"model": model, "guardrails": ["request-rule"]}
+        ),
     }
-    synthetic = proxy_logging._convert_mcp_to_llm_format(proxy_logging._create_mcp_request_object_from_kwargs(kwargs), kwargs)
+    synthetic = proxy_logging._convert_mcp_to_llm_format(
+        proxy_logging._create_mcp_request_object_from_kwargs(kwargs), kwargs
+    )
     assert ("model-rule" in synthetic["metadata"]["guardrails"]) is expected
     assert "request-rule" in synthetic["metadata"]["guardrails"]
 
@@ -4365,7 +4415,5 @@ def test_is_client_error_exception_existing_behaviour_unchanged() -> None:
 
     assert _is_client_error_exception(HTTPException(status_code=400, detail="x")) is True
     assert _is_client_error_exception(HTTPException(status_code=500, detail="x")) is False
-    assert _is_client_error_exception(
-        ProxyException(message="x", type="x", param=None, code="429")
-    ) is True
+    assert _is_client_error_exception(ProxyException(message="x", type="x", param=None, code="429")) is True
     assert _is_client_error_exception(ValueError("x")) is False
diff --git a/tests/unit/proxy/test_response_polling_pre_call_checks.py b/tests/unit/proxy/test_response_polling_pre_call_checks.py
index c6e4301a501..4228c1ff8f8 100644
--- a/tests/unit/proxy/test_response_polling_pre_call_checks.py
+++ b/tests/unit/proxy/test_response_polling_pre_call_checks.py
@@ -6,6 +6,8 @@ BEFORE a polling ID is created, so rate-limited requests get a
 synchronous error instead of a polling ID that immediately fails.
 """
 
+from collections.abc import Mapping
+from typing import Final
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
@@ -83,7 +85,7 @@ class TestSkipPreCallLogic:
         ):
             try:
                 await processor.base_process_llm_request(
-                    request=MagicMock(spec=Request),
+                    request=MagicMock(spec=Request, headers={}),
                     fastapi_response=MagicMock(spec=Response),
                     user_api_key_dict=UserAPIKeyAuth(),
                     route_type="aresponses",
@@ -176,3 +178,77 @@ class TestPollingEndpointPreCallGuard:
 
         assert exc_info.value.status_code == 429
         generate_polling_id_mock.assert_not_called()
+
+
+async def _polled_background_response(
+    body: Mapping[str, object], headers: Mapping[str, str]
+) -> tuple[MagicMock, Mapping[str, object]]:
+    from litellm.proxy.response_api_endpoints.endpoints import responses_api
+    from litellm.proxy.response_polling.polling_handler import ResponsePollingHandler
+
+    generate_polling_id: Final = MagicMock(return_value="litellm_poll_test")
+    pre_call_saw: Final[list[Mapping[str, object]]] = []
+
+    async def pre_call(processor: ProxyBaseLLMRequestProcessing, **_: object) -> tuple[Mapping[str, object], MagicMock]:
+        pre_call_saw.append(dict(processor.data))
+        return processor.data, MagicMock()
+
+    request: Final = MagicMock(spec=Request)
+    request.headers = headers
+    proxy_server_patches: Final[Mapping[str, object]] = {
+        "read_request_body": AsyncMock(return_value=dict(body)),
+        "general_settings": {},
+        "llm_router": MagicMock(),
+        "native_background_mode": None,
+        "polling_cache_ttl": 3600,
+        "polling_via_cache_enabled": True,
+        "proxy_config": MagicMock(),
+        "proxy_logging_obj": AsyncMock(),
+        "redis_usage_cache": AsyncMock(),
+        "user_api_base": None,
+        "user_max_tokens": None,
+        "user_model": None,
+        "user_request_timeout": None,
+        "user_temperature": None,
+        "version": "1.0.0",
+    }
+    with (
+        patch.multiple("litellm.proxy.proxy_server", **proxy_server_patches),
+        patch("litellm.proxy.response_polling.polling_handler.should_use_polling_for_request", return_value=True),
+        patch.object(ProxyBaseLLMRequestProcessing, "common_processing_pre_call_logic", pre_call),
+        patch.object(
+            ProxyBaseLLMRequestProcessing,
+            "handle_llm_api_exception",
+            new_callable=AsyncMock,
+            side_effect=lambda e, **_: e,
+        ),
+        patch("litellm.proxy.response_api_endpoints.endpoints.raise_if_required_body_param_missing"),
+        patch.object(ResponsePollingHandler, "generate_polling_id", generate_polling_id),
+        patch("asyncio.create_task"),
+        patch.object(ResponsePollingHandler, "create_initial_state", new_callable=AsyncMock, return_value=MagicMock()),
+    ):
+        await responses_api(
+            request=request, fastapi_response=MagicMock(spec=Response), user_api_key_dict=MagicMock(spec=UserAPIKeyAuth)
+        )
+    return generate_polling_id, pre_call_saw[0] if pre_call_saw else {}
+
+
+@pytest.mark.asyncio
+async def test_a_body_total_timeout_on_a_polled_background_response_is_refused_before_a_polling_id_is_issued() -> None:
+    from litellm.proxy._types import ProxyException
+
+    with pytest.raises(ProxyException) as refused:
+        _ = await _polled_background_response({"model": "gpt-4", "background": True, "total_timeout": 10}, {})
+
+    assert refused.value.code == "400"
+    assert refused.value.param == "total_timeout"
+
+
+@pytest.mark.asyncio
+async def test_a_header_total_timeout_on_a_polled_background_response_is_dropped_and_polling_proceeds() -> None:
+    generate_polling_id, pre_call_saw = await _polled_background_response(
+        {"model": "gpt-4", "background": True, "total_timeout": "ignored"}, {"x-litellm-total-timeout": "10"}
+    )
+
+    generate_polling_id.assert_called_once()
+    assert "total_timeout" not in pre_call_saw
diff --git a/tests/unit/proxy/test_route_llm_request.py b/tests/unit/proxy/test_route_llm_request.py
index 25c62034f56..7f384d8e6bf 100644
--- a/tests/unit/proxy/test_route_llm_request.py
+++ b/tests/unit/proxy/test_route_llm_request.py
@@ -1,29 +1,24 @@
 import asyncio
 import contextlib
 import gc
+import json
 import threading
 import weakref
-import httpx
-import json
-import litellm
-import pytest
-import redis
-import respx
-
-
 from collections.abc import Awaitable, Callable, Coroutine, Iterator, Mapping
 from datetime import datetime
 from types import SimpleNamespace
-from uuid import uuid4
 from typing import Final
 from unittest.mock import MagicMock
+from uuid import uuid4
 
-from litellm.router_api import RouterSettings
-from tests.unit.proxy.router_entry_point_stubs import route_entry_points_to_stubs
-
+import httpx
+import pytest
+import redis
+import respx
 from fakeredis import TcpFakeServer
 from fastapi import HTTPException
 
+import litellm
 from litellm.caching.caching import DualCache
 from litellm.litellm_core_utils.logging_worker import GLOBAL_LOGGING_WORKER
 from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
@@ -37,11 +32,13 @@ from litellm.proxy.route_llm_request import (
     user_config_routers,
 )
 from litellm.proxy.utils import ProxyLogging
+from litellm.router_api import RouterSettings
 from litellm.router_strategy.adaptive_router.config import (
     ADAPTIVE_ROUTER_CHOSEN_MODEL_KEY,
     ADAPTIVE_ROUTER_RESPONSE_HEADER,
 )
 from litellm.types.router import RouterErrors, RouterGeneralSettings, RouterRateLimitError
+from tests.unit.proxy.router_entry_point_stubs import route_entry_points_to_stubs
 
 
 @pytest.mark.parametrize(
@@ -79,7 +76,6 @@ async def test_route_request_dynamic_credentials(route_type, required_body_param
 @pytest.mark.asyncio
 async def test_route_request_proxy_admin_can_call_all_team_scoped_deployments_without_team_id():
     import litellm
-
     from litellm.proxy._types import LitellmUserRoles, UserAPIKeyAuth
 
     router = litellm.Router(
@@ -671,7 +667,6 @@ async def test_route_request_forwards_mock_params_when_opted_in(monkeypatch):
     """End-to-end through ``route_request``: with the opt-in set the param
     reaches the router, which is what makes a fallback drill possible."""
     import litellm.proxy.proxy_server as proxy_server
-
     from litellm.proxy.route_llm_request import MOCK_TESTING_CONFIG_KEY
 
     monkeypatch.setattr(
@@ -776,10 +771,12 @@ async def test_route_request_realtime_wildcard_model_resolves_credentials(
     POST /realtime/client_secrets with a request model like openai/gpt-realtime
     must match an openai/* deployment and forward its api_key upstream.
     """
-    import httpx
-    import litellm
     from unittest.mock import AsyncMock, patch
 
+    import httpx
+
+    import litellm
+
     monkeypatch.delenv("OPENAI_API_KEY", raising=False)
 
     router = litellm.Router(
@@ -814,10 +811,12 @@ async def test_route_request_realtime_team_scoped_model_resolves_credentials(
     Team-scoped deployments (team_public_model_name) must be selected when
     user_api_key_team_id is present, same as /chat/completions.
     """
-    import httpx
-    import litellm
     from unittest.mock import AsyncMock, patch
 
+    import httpx
+
+    import litellm
+
     monkeypatch.delenv("OPENAI_API_KEY", raising=False)
 
     router = litellm.Router(
@@ -860,10 +859,12 @@ async def test_route_request_realtime_litellm_credential_name_resolves_api_key(
     litellm_credential_name on a wildcard deployment must resolve to the stored
     api_key when routing acreate_realtime_client_secret through the router.
     """
-    import httpx
-    import litellm
     from unittest.mock import AsyncMock, patch
 
+    import httpx
+
+    import litellm
+
     monkeypatch.delenv("OPENAI_API_KEY", raising=False)
 
     router = litellm.Router(
@@ -895,9 +896,9 @@ async def test_route_request_realtime_unresolvable_model_raises_not_found(
     An unknown model must not silently fall through to litellm with an empty
     OPENAI_API_KEY env var.
     """
-    import litellm
     from unittest.mock import AsyncMock, patch
 
+    import litellm
     from litellm.proxy.route_llm_request import ProxyModelNotFoundError
 
     monkeypatch.delenv("OPENAI_API_KEY", raising=False)
@@ -927,10 +928,12 @@ async def test_route_request_realtime_calls_resolves_api_base(monkeypatch):
     non-default (self-hosted / proxied) OpenAI endpoint is honored, instead of
     defaulting to https://api.openai.com.
     """
-    import httpx
-    import litellm
     from unittest.mock import AsyncMock, patch
 
+    import httpx
+
+    import litellm
+
     monkeypatch.delenv("OPENAI_API_KEY", raising=False)
     monkeypatch.delenv("OPENAI_API_BASE", raising=False)
 
@@ -970,10 +973,12 @@ async def test_route_request_realtime_transcription_session_resolves_credentials
     /realtime/transcription_sessions must resolve credentials through the router
     (wildcard deployment) rather than falling back to an empty OPENAI_API_KEY.
     """
-    import httpx
-    import litellm
     from unittest.mock import AsyncMock, patch
 
+    import httpx
+
+    import litellm
+
     monkeypatch.delenv("OPENAI_API_KEY", raising=False)
 
     router = litellm.Router(
@@ -1400,7 +1405,9 @@ async def test_route_request_applies_override_fallbacks_when_request_carries_cre
 @pytest.mark.parametrize(
     "router_only_setting",
     [
-        pytest.param({"model_group_retry_policy": {"gpt-4": {"TimeoutErrorRetries": 1}}}, id="model-group-retry-policy"),
+        pytest.param(
+            {"model_group_retry_policy": {"gpt-4": {"TimeoutErrorRetries": 1}}}, id="model-group-retry-policy"
+        ),
         pytest.param({"context_window_fallbacks": [{"gpt-4": ["gpt-3.5-turbo"]}]}, id="context-window-fallbacks"),
         pytest.param({"content_policy_fallbacks": [{"gpt-4": ["gpt-3.5-turbo"]}]}, id="content-policy-fallbacks"),
     ],
@@ -2103,11 +2110,12 @@ async def test_route_request_read_through_disabled_without_store_model_in_db(mon
 
 @pytest.mark.asyncio
 async def test_route_request_read_through_supplies_db_model_default_for_missing_param(monkeypatch):
-    import litellm
-    import litellm.proxy.proxy_server as proxy_server
     from types import SimpleNamespace
     from unittest.mock import AsyncMock, patch
 
+    import litellm
+    import litellm.proxy.proxy_server as proxy_server
+
     model_name = "e2e-db-only-max-tokens-default"
     router = litellm.Router(
         model_list=[{"model_name": "some-other-model", "litellm_params": {"model": "openai/gpt-4o", "api_key": "fake"}}]
@@ -2662,7 +2670,9 @@ async def test_a_user_config_adaptive_request_answers_with_the_model_it_picked()
                 },
                 {
                     **_mock_deployment("smart"),
-                    "model_info": {"adaptive_router_preferences": {"quality_tier": 3, "strengths": ["code_generation"]}},
+                    "model_info": {
+                        "adaptive_router_preferences": {"quality_tier": 3, "strengths": ["code_generation"]}
+                    },
                 },
             ]
         },
@@ -3125,3 +3135,47 @@ def test_fallback_probe_skips_only_a_loaded_model_that_refuses_the_route() -> No
     assert skipped("embed-only") is True
     assert skipped("chat-fallback") is False
     assert skipped("added-on-another-worker") is False
+
+
+def _router_answering_hi() -> "litellm.Router":
+    import litellm
+
+    return litellm.Router(
+        model_list=[{"model_name": "g", "litellm_params": {"model": "openai/gpt-5.4-nano", "mock_response": "hi"}}]
+    )
+
+
+@pytest.mark.parametrize("flag", ["stream", "background"])
+@pytest.mark.asyncio
+async def test_a_request_a_hook_made_stream_or_run_in_the_background_is_refused_under_a_body_total_timeout(
+    flag: str,
+) -> None:
+    from litellm.litellm_core_utils.total_deadline import TotalTimeoutNotApplicable, total_deadline
+
+    async with total_deadline(60, from_body=True):
+        with pytest.raises(TotalTimeoutNotApplicable):
+            await route_request(
+                data={"model": "g", "messages": [{"role": "user", "content": "hi"}], flag: True},
+                llm_router=_router_answering_hi(),
+                user_model=None,
+                route_type="acompletion",
+            )
+
+
+@pytest.mark.asyncio
+async def test_a_request_a_hook_turned_streaming_runs_unbounded_under_a_header_total_timeout() -> None:
+    from litellm.litellm_core_utils.total_deadline import current_total_deadline, total_deadline
+
+    async with total_deadline(60, from_body=False):
+        llm_call: Final = await route_request(
+            data={"model": "g", "messages": [{"role": "user", "content": "hi"}], "stream": True},
+            llm_router=_router_answering_hi(),
+            user_model=None,
+            route_type="acompletion",
+        )
+        stream: Final = await llm_call
+        chunks: Final = [chunk async for chunk in stream]
+        deadline: Final = current_total_deadline()
+
+    assert chunks
+    assert deadline is not None and deadline.allows_wait(10**9)
diff --git a/tests/unit/test_router/core/test_retries_cooldowns.py b/tests/unit/test_router/core/test_retries_cooldowns.py
index 004b1762240..d5ffa8491b1 100644
--- a/tests/unit/test_router/core/test_retries_cooldowns.py
+++ b/tests/unit/test_router/core/test_retries_cooldowns.py
@@ -13,6 +13,7 @@ import pytest
 
 import litellm
 from litellm.constants import DEFAULT_COOLDOWN_TIME_SECONDS, INITIAL_RETRY_DELAY, JITTER
+from litellm.litellm_core_utils.total_deadline import TotalTimeoutNotApplicable, total_deadline
 from litellm.router_api import ChangeSet
 from litellm.router_core import RouterCore
 from litellm.types.router import AllowedFailsPolicy, RetryPolicy
@@ -430,6 +431,60 @@ async def test_lone_deployment_waits_the_retry_after_header(make_core: MakeCore,
     assert all(7 <= slept < 7 + JITTER for slept in host.sleeps[:2])
 
 
+@pytest.mark.parametrize(
+    ("budget", "expected_calls"),
+    [(10, 2), (100, 4)],
+    ids=["second_backoff_outlasts_the_budget", "every_backoff_fits_the_budget"],
+)
+@pytest.mark.asyncio
+async def test_a_retry_runs_only_while_its_backoff_fits_the_total_timeout(
+    make_core: MakeCore, host: ScriptedHost, budget: float, expected_calls: int
+) -> None:
+    core: Final = make_core(model_list=[deployment("g", "a")], num_retries=3)
+    host.answer("openai/a", lambda **_: rate_limited(retry_after="6"))
+
+    async with total_deadline(budget, from_body=True, clock=lambda: sum(host.sleeps)):
+        failure: Final = await attempt(core)
+
+    assert isinstance(failure, litellm.RateLimitError)
+    assert len(host.calls_to("acompletion")) == expected_calls
+    assert sum(host.sleeps) < budget
+
+
+@pytest.mark.asyncio
+async def test_a_streaming_attempt_under_a_body_total_timeout_is_refused_before_the_provider_is_called(
+    make_core: MakeCore, host: ScriptedHost
+) -> None:
+    core: Final = make_core(
+        model_list=[deployment("g", "a")],
+        num_retries=3,
+    )
+    host.answer("openai/a", lambda **_: litellm.ModelResponse())
+
+    async with total_deadline(10, from_body=True):
+        refused: Final = await attempt(core, stream=True)
+
+    assert isinstance(refused, TotalTimeoutNotApplicable)
+    assert host.calls_to("acompletion") == []
+
+
+@pytest.mark.asyncio
+async def test_a_streaming_attempt_under_a_header_total_timeout_runs_unbounded(
+    make_core: MakeCore, host: ScriptedHost
+) -> None:
+    core: Final = make_core(
+        model_list=[deployment("g", "a")],
+        num_retries=3,
+    )
+    host.answer("openai/a", lambda **_: rate_limited(retry_after="6"))
+
+    async with total_deadline(10, from_body=False, clock=lambda: sum(host.sleeps)):
+        failure: Final = await attempt(core, stream=True)
+
+    assert isinstance(failure, litellm.RateLimitError)
+    assert len(host.calls_to("acompletion")) == 4
+
+
 @pytest.mark.asyncio
 async def test_lone_deployment_ignores_a_retry_after_header_over_a_minute(
     make_core: MakeCore, host: ScriptedHost