diff --git a/litellm-proxy-extras/litellm_proxy_extras/migrations/20260813180408_add_shadow_eval_direction/migration.sql b/litellm-proxy-extras/litellm_proxy_extras/migrations/20260813180408_add_shadow_eval_direction/migration.sql
new file mode 100644
index 00000000000..57c9abab07d
--- /dev/null
+++ b/litellm-proxy-extras/litellm_proxy_extras/migrations/20260813180408_add_shadow_eval_direction/migration.sql
@@ -0,0 +1,8 @@
+-- AlterTable
+ALTER TABLE "LiteLLM_ShadowEvalJob" ADD COLUMN     "baseline_model" TEXT,
+ADD COLUMN     "direction" TEXT NOT NULL DEFAULT 'forward';
+
+DROP INDEX IF EXISTS "LiteLLM_ShadowEvalJob_one_active_per_key";
+
+CREATE UNIQUE INDEX IF NOT EXISTS "LiteLLM_ShadowEvalJob_one_active_per_key_direction"
+    ON "LiteLLM_ShadowEvalJob"("api_key_id", "direction") WHERE "stopped_at" IS NULL;
diff --git a/litellm-proxy-extras/litellm_proxy_extras/schema.prisma b/litellm-proxy-extras/litellm_proxy_extras/schema.prisma
index 79d778fb464..71345d2ccde 100644
--- a/litellm-proxy-extras/litellm_proxy_extras/schema.prisma
+++ b/litellm-proxy-extras/litellm_proxy_extras/schema.prisma
@@ -1450,15 +1450,20 @@ model LiteLLM_AutoRouterSession {
   @@index([last_turn_at], map: "idx_autorouter_session_last_turn")
 }
 
-// Shadow eval: pre-adoption evaluation of an auto-router against a key's live traffic.
-// A sampled slice of requests is duplicated through the router in a detached task and an
-// LLM judge compares real vs shadow responses blind. The job row is immutable config plus
+// Shadow eval: evaluation of an auto-router against a key's live traffic, in either
+// direction. forward duplicates the requests the key did not route through the router
+// through it, answering whether the key should adopt it; reverse duplicates the requests
+// the router did serve against a fixed baseline model, answering whether a key already on
+// it still benefits. Either way a sampled slice runs in a detached task and an LLM judge
+// compares real vs shadow responses blind. The job row is immutable config plus
 // stopped_at; every count, status, and spend figure is derived from the append-only
 // attempt rows, so nothing can disagree across pods or stop races.
 model LiteLLM_ShadowEvalJob {
   id                String   @id @default(cuid())
   api_key_id        String   // hashed virtual key whose traffic is shadowed
-  router_name       String
+  router_name       String   // the auto-router under evaluation, in either direction
+  direction         String   @default("forward") // forward | reverse
+  baseline_model    String?  // reverse only: the fixed model the router is judged against
   judge_model       String
   shadow_percentage Float
   max_turns         Int      // sample budget: judge at most this many turns
diff --git a/litellm/caching/redis_cache.py b/litellm/caching/redis_cache.py
index 5fedfc5bcce..a3936fd17e2 100644
--- a/litellm/caching/redis_cache.py
+++ b/litellm/caching/redis_cache.py
@@ -1572,7 +1572,7 @@ class RedisCache(BaseCache):
     async def _pipeline_rpush_helper(
         self,
         pipe: pipeline,
-        rpush_list: list[RedisPipelineRpushOperation],
+        rpush_list: Sequence[RedisPipelineRpushOperation],
     ) -> list[int]:
         """Helper function for pipeline rpush operations"""
         for rpush_op in rpush_list:
@@ -1588,7 +1588,7 @@ class RedisCache(BaseCache):
     @_redis_circuit_breaker_guard
     async def async_rpush_pipeline(
         self,
-        rpush_list: list[RedisPipelineRpushOperation],
+        rpush_list: Sequence[RedisPipelineRpushOperation],
     ) -> list[int]:
         """
         Use Redis Pipelines for bulk RPUSH operations
diff --git a/litellm/integrations/shadow_eval_logger.py b/litellm/integrations/shadow_eval_logger.py
index c7b89e0e9b0..ca9b6982414 100644
--- a/litellm/integrations/shadow_eval_logger.py
+++ b/litellm/integrations/shadow_eval_logger.py
@@ -1,5 +1,6 @@
 """Shadow Eval Logger: samples a shadowed key's successful chat requests, duplicates each
-through the auto-router in a detached task, blind-judges real vs shadow, and appends one
+against the job's other arm in a detached task (the auto-router for a forward job, the
+fixed baseline model for a reverse one), blind-judges real vs shadow, and appends one
 ``LiteLLM_ShadowEvalAttempt`` row (verdict or error) as the feature's only hot-path write.
 Counts, status, and spend derive from those rows at read time, so nothing can disagree
 across pods or stop races; the hook reads active jobs through a short-TTL cache."""
@@ -10,10 +11,12 @@ import random
 from collections.abc import Callable, Mapping, Sequence
 from dataclasses import dataclass
 from datetime import datetime, timezone
+from itertools import groupby
+from operator import itemgetter
 from types import MappingProxyType
 from typing import TYPE_CHECKING, Final
 
-from pydantic import BaseModel
+from pydantic import BaseModel, ConfigDict, ValidationError, field_validator, model_validator
 
 from litellm._logging import verbose_logger
 from litellm.caching.in_memory_cache import InMemoryCache
@@ -28,6 +31,7 @@ from litellm.litellm_core_utils.llm_judge import (
     parse_json_verdict,
 )
 from litellm.litellm_core_utils.redact_messages import should_redact_message_logging
+from litellm.types.management_endpoints.auto_router_endpoints import ShadowEvalDirection
 from litellm.types.utils import SHADOW_EVAL_JUDGE_CALL_ORIGIN, SHADOW_EVAL_ROUTER_CALL_ORIGIN
 
 if TYPE_CHECKING:
@@ -161,13 +165,26 @@ async def _key_or_team_is_over_budget(metadata: Mapping[str, object]) -> bool:
     return False
 
 
+def _routing_decision(metadata: Mapping[str, object]) -> Mapping[str, object]:
+    """The routing decision a pre-routing strategy wrote to a call's metadata, empty when
+    a plain model served it. Read off the sampled request for the control arm, and off the
+    shadow call's own write-back for the shadow arm."""
+    decision: Final = metadata.get("routing_decision")
+    return decision if isinstance(decision, Mapping) else _EMPTY_METADATA
+
+
+def _routed_tier(metadata: Mapping[str, object]) -> str | None:
+    decision: Final = _routing_decision(metadata)
+    raw: Final = decision.get("tier_label") or decision.get("tier")
+    return str(raw) if raw is not None else None
+
+
 def _request_was_routed_by(request_metadata: Mapping[str, object], router_name: str) -> bool:
-    """Duplicating a request the shadowed router already served compares the router to
-    itself: guaranteed ties, judge spend for zero information."""
-    decision: Final = request_metadata.get("routing_decision")
-    if not isinstance(decision, Mapping):
-        return False
-    return decision.get("router_model_name") == router_name
+    """Whether the router under evaluation served this request, which is what decides
+    the direction it belongs to. A forward job skips its own router's traffic, since
+    duplicating it would compare the router to itself: guaranteed ties, judge spend for
+    zero information. A reverse job samples exactly that traffic and nothing else."""
+    return _routing_decision(request_metadata).get("router_model_name") == router_name
 
 
 @dataclass(frozen=True, slots=True)
@@ -197,22 +214,53 @@ class _JudgeVerdict:
     cost: float
 
 
-@dataclass(frozen=True, slots=True)
-class ActiveShadowEvalJob:
-    """One active job as the sampling path needs it: immutable config plus the attempt
-    count as of the cache fill (the turn budget's staleness is bounded by the cache TTL)."""
+class ActiveShadowEvalJob(BaseModel):
+    """One active job as the sampling path needs it, validated straight off the untyped
+    job row: immutable config plus the attempt count as of the cache fill (the turn
+    budget's staleness is bounded by the cache TTL). Every way a row can be unsamplable
+    is a validation error here, so a bad row is skipped rather than sampled wrongly."""
+
+    model_config = ConfigDict(frozen=True, from_attributes=True)
 
     id: str
     router_name: str
+    direction: ShadowEvalDirection = "forward"
+    baseline_model: str | None = None
     shadow_percentage: float
     judge_model: str
     max_turns: int
     ends_at: datetime
-    attempts: int
+    attempts: int = 0
+
+    @field_validator("ends_at")
+    @classmethod
+    def _as_utc(cls, value: datetime) -> datetime:
+        return value.replace(tzinfo=timezone.utc) if value.tzinfo is None else value
+
+    @model_validator(mode="after")
+    def _baseline_model_matches_direction(self) -> "ActiveShadowEvalJob":
+        if (self.baseline_model is not None) != (self.direction == "reverse"):
+            raise ValueError("baseline_model is set for exactly the reverse jobs")
+        return self
+
+    @property
+    def shadow_target(self) -> str:
+        """The model the duplicated arm calls: the router itself for a forward job, the
+        fixed baseline for a reverse one. Total because the validator above pins
+        baseline_model to reverse jobs and only those."""
+        return self.baseline_model or self.router_name
 
 
-def _as_utc(value: datetime) -> datetime:
-    return value.replace(tzinfo=timezone.utc) if value.tzinfo is None else value
+def _as_active_job(record: object, attempts: int) -> ActiveShadowEvalJob | None:
+    """The sampling path's view of one job row, or None for a row it cannot sample: an
+    unknown direction, or a reverse job with no baseline model to duplicate against.
+    Failing closed here is what keeps the dispatch path total."""
+    try:
+        job: Final = ActiveShadowEvalJob.model_validate(record)
+    except ValidationError as e:
+        verbose_logger.debug("shadow_eval: skipping unsamplable job row: %s", e)
+        return None
+    return job.model_copy(update={"attempts": attempts})
 
 
 _jobs_cache: Final = InMemoryCache(max_size_in_memory=4, default_ttl=_JOBS_CACHE_TTL_SECONDS)
@@ -238,8 +286,9 @@ class ShadowEvalLogger(CustomLogger):
         # generation; the refill absorbs written rows and resets.
         self._job_starts: dict[str, int] = {}  # mutable-ok: per-generation counter
 
-    async def _active_jobs(self) -> Mapping[str, ActiveShadowEvalJob]:
-        """Active jobs by api_key_id, cache-first. A DB fault returns empty without
+    async def _active_jobs(self) -> Mapping[str, tuple[ActiveShadowEvalJob, ...]]:
+        """Active jobs by api_key_id, cache-first. A key holds at most one job per
+        direction, so the value is a collection. A DB fault returns empty without
         caching, so sampling pauses for that request and the next one retries."""
         cached: Final = await self._jobs_cache.async_get_cache(_JOBS_CACHE_KEY)
         if cached is not None:
@@ -264,18 +313,19 @@ class ShadowEvalLogger(CustomLogger):
                 else ()
             )
             attempt_counts: Final = {str(row["job_id"]): int(row["_count"]["_all"]) for row in grouped or []}
-            jobs: Final = {
-                str(record.api_key_id): ActiveShadowEvalJob(
-                    id=str(record.id),
-                    router_name=str(record.router_name),
-                    shadow_percentage=float(record.shadow_percentage),
-                    judge_model=str(record.judge_model),
-                    max_turns=int(record.max_turns),
-                    ends_at=_as_utc(record.ends_at),
-                    attempts=attempt_counts.get(str(record.id), 0),
+            by_key: Final = tuple(
+                sorted(
+                    (
+                        (str(record.api_key_id), job)
+                        for record in records or []
+                        if (job := _as_active_job(record, attempt_counts.get(str(record.id), 0))) is not None
+                    ),
+                    key=itemgetter(0),
                 )
-                for record in records or []
-            }
+            )
+            jobs: Final = MappingProxyType(
+                {key: tuple(job for _, job in group) for key, group in groupby(by_key, key=itemgetter(0))}
+            )
             await self._jobs_cache.async_set_cache(_JOBS_CACHE_KEY, jobs)
             self._job_starts = {}  # rebind-ok: new generation, counts absorbed into the fill
             return jobs
@@ -308,43 +358,46 @@ class ShadowEvalLogger(CustomLogger):
             api_key_hash: Final = metadata.get("user_api_key_hash")
             if not api_key_hash:
                 return
-            job: Final = (await self._active_jobs()).get(str(api_key_hash))
-            if job is None:
-                return
-            if datetime.now(timezone.utc) >= job.ends_at:
-                return
-            if job.attempts + self._job_starts.get(job.id, 0) >= job.max_turns:
-                return
             request_id: Final = payload.get("id") or ""
             if not request_id:
                 return
-            if not _sample_hits(request_id, job.id, job.shadow_percentage):
-                return
             if payload.get("call_type") not in _SAMPLED_CALL_TYPES:
                 return  # only known chat-shaped traffic is comparable; unknown or missing types fail closed
-            if _request_was_routed_by(request_metadata, job.router_name):
-                return
-            if self._inflight_shadow_tasks >= _MAX_CONCURRENT_SHADOW_TASKS:
-                return
             raw_messages: Final = kwargs.get("messages")
-            self._job_starts[job.id] = self._job_starts.get(job.id, 0) + 1
-            self._inflight_shadow_tasks += 1
-            task: Final = asyncio.create_task(
-                self._run_shadow_eval(
-                    job=job,
-                    request_id=request_id,
-                    messages=tuple(m for m in raw_messages if isinstance(m, Mapping))
-                    if isinstance(raw_messages, Sequence)
-                    else (),
-                    response_obj=response_obj,
-                    real_model=payload.get("model") or "",
-                    model_parameters=MappingProxyType(
-                        dict(payload.get("model_parameters") or {})  # mutable-ok: frozen snapshot
-                    ),
-                    parent_metadata=MappingProxyType(dict(request_metadata)),  # mutable-ok: frozen snapshot
-                )
+            messages: Final = (
+                tuple(m for m in raw_messages if isinstance(m, Mapping)) if isinstance(raw_messages, Sequence) else ()
             )
-            task.add_done_callback(self._release_shadow_slot)
+            control_tier: Final = _routed_tier(request_metadata)
+            # A key can hold one job per direction, and a request routed by one job's
+            # router while bypassing the other's qualifies for both. Each is separately
+            # budgeted, so both fire.
+            for job in (await self._active_jobs()).get(str(api_key_hash), ()):
+                if datetime.now(timezone.utc) >= job.ends_at:
+                    continue
+                if job.attempts + self._job_starts.get(job.id, 0) >= job.max_turns:
+                    continue
+                if not _sample_hits(request_id, job.id, job.shadow_percentage):
+                    continue
+                if _request_was_routed_by(request_metadata, job.router_name) != (job.direction == "reverse"):
+                    continue
+                if self._inflight_shadow_tasks >= _MAX_CONCURRENT_SHADOW_TASKS:
+                    return
+                self._job_starts[job.id] = self._job_starts.get(job.id, 0) + 1
+                self._inflight_shadow_tasks += 1
+                asyncio.create_task(
+                    self._run_shadow_eval(
+                        job=job,
+                        request_id=request_id,
+                        messages=messages,
+                        response_obj=response_obj,
+                        real_model=payload.get("model") or "",
+                        control_tier=control_tier,
+                        model_parameters=MappingProxyType(
+                            dict(payload.get("model_parameters") or {})  # mutable-ok: frozen snapshot
+                        ),
+                        parent_metadata=MappingProxyType(dict(request_metadata)),  # mutable-ok: frozen snapshot
+                    )
+                ).add_done_callback(self._release_shadow_slot)
         except Exception as e:  # noqa: BLE001  # logging hooks must never fail the request
             verbose_logger.debug("shadow_eval: failed to schedule task: %s", e)
 
@@ -360,6 +413,7 @@ class ShadowEvalLogger(CustomLogger):
         messages: Sequence[Mapping[str, object]],
         response_obj: object,
         real_model: str,
+        control_tier: str | None,
         model_parameters: Mapping[str, object],
         parent_metadata: Mapping[str, object],
     ) -> None:
@@ -376,9 +430,11 @@ class ShadowEvalLogger(CustomLogger):
             if await _key_or_team_is_over_budget(parent_metadata):
                 return
 
-            shadow: Final = await self._call_router_shadow(job.router_name, messages, model_parameters, parent_metadata)
+            shadow: Final = await self._call_router_shadow(
+                job.shadow_target, messages, model_parameters, parent_metadata
+            )
             if isinstance(shadow, _CallFailure):
-                await self._record_attempt(prisma, job, request_id, outcome="error", error=shadow.error)
+                await self._record_attempt(prisma, job, request_id, control_tier, outcome="error", error=shadow.error)
                 return
 
             verdict: Final = await self._call_judge(
@@ -393,6 +449,7 @@ class ShadowEvalLogger(CustomLogger):
                     prisma,
                     job,
                     request_id,
+                    control_tier,
                     outcome="error",
                     error=verdict.error,
                     shadow=shadow,
@@ -403,6 +460,7 @@ class ShadowEvalLogger(CustomLogger):
                 prisma,
                 job,
                 request_id,
+                control_tier,
                 outcome=verdict.preference,
                 shadow=shadow,
                 real_model=real_model,
@@ -411,13 +469,16 @@ class ShadowEvalLogger(CustomLogger):
             )
         except Exception as e:  # noqa: BLE001  # detached task: record what happened, never raise
             verbose_logger.debug("shadow_eval: pipeline failed for %s: %s", request_id, e)
-            await self._record_attempt(prisma, job, request_id, outcome="error", error=f"pipeline error: {e}")
+            await self._record_attempt(
+                prisma, job, request_id, control_tier, outcome="error", error=f"pipeline error: {e}"
+            )
 
     @staticmethod
     async def _record_attempt(
         prisma: "PrismaClient | None",
         job: ActiveShadowEvalJob,
         request_id: str,
+        control_tier: str | None,
         *,
         outcome: str,
         shadow: _ShadowResponse | None = None,
@@ -434,7 +495,7 @@ class ShadowEvalLogger(CustomLogger):
                     "job_id": job.id,
                     "request_id": request_id,
                     "outcome": outcome,
-                    "tier": shadow.tier if shadow else None,
+                    "tier": control_tier if job.direction == "reverse" else (shadow.tier if shadow else None),
                     "real_model": real_model or None,
                     "shadow_model": shadow.model if shadow else None,
                     "confidence": confidence,
@@ -447,14 +508,15 @@ class ShadowEvalLogger(CustomLogger):
 
     async def _call_router_shadow(
         self,
-        router_name: str,
+        target_model: str,
         messages: Sequence[Mapping[str, object]],
         model_parameters: Mapping[str, object],
         parent_metadata: Mapping[str, object],
     ) -> "_ShadowResponse | _CallFailure":
-        """Send the prompt through the auto-router being evaluated. The metadata carries
-        the shadowed key's identity (spend attribution) and receives the router's routing
-        decision write-back, read back for tier attribution."""
+        """Send the prompt through the arm nobody was served: the auto-router under
+        evaluation, or a reverse job's fixed baseline model. The metadata carries the
+        shadowed key's identity (spend attribution) and receives a routing decision
+        write-back, which a plain baseline model simply never makes."""
         router: Final = self._router_provider()
         if router is None:
             return _CallFailure("no router configured on this pod")
@@ -466,7 +528,7 @@ class ShadowEvalLogger(CustomLogger):
         }
         try:
             response: Final = await router.acompletion(
-                model=router_name,
+                model=target_model,
                 messages=messages,  # pyright: ignore[reportArgumentType]  # snapshot of the SDK's own message dicts
                 metadata=shadow_metadata,
                 num_retries=0,
@@ -479,13 +541,10 @@ class ShadowEvalLogger(CustomLogger):
         text: Final = self._extract_response_text(response)
         if not text:
             return _CallFailure("shadow router returned an empty response")
-        raw_decision: Final = shadow_metadata.get("routing_decision")
-        routing_decision: Final = raw_decision if isinstance(raw_decision, Mapping) else _EMPTY_METADATA
-        raw_tier: Final = routing_decision.get("tier_label") or routing_decision.get("tier")
         return _ShadowResponse(
             text=text,
-            model=str(getattr(response, "model", None) or routing_decision.get("routed_model") or ""),
-            tier=str(raw_tier) if raw_tier is not None else None,
+            model=str(getattr(response, "model", None) or _routing_decision(shadow_metadata).get("routed_model") or ""),
+            tier=_routed_tier(shadow_metadata),
         )
 
     async def _call_judge(
@@ -552,7 +611,7 @@ class ShadowEvalLogger(CustomLogger):
         return extract_text_from_content(content)
 
 
-_EMPTY_JOBS: Final[Mapping[str, ActiveShadowEvalJob]] = MappingProxyType({})
+_EMPTY_JOBS: Final[Mapping[str, tuple[ActiveShadowEvalJob, ...]]] = MappingProxyType({})
 
 
 def _default_prisma_provider() -> "PrismaClient | None":
diff --git a/litellm/llms/azure_ai/vector_stores/transformation.py b/litellm/llms/azure_ai/vector_stores/transformation.py
index 5e16d759be1..5e61d0a1dd9 100644
--- a/litellm/llms/azure_ai/vector_stores/transformation.py
+++ b/litellm/llms/azure_ai/vector_stores/transformation.py
@@ -37,9 +37,32 @@ class AzureAIVectorStoreConfig(BaseVectorStoreConfig, BaseAzureLLM):
         super().__init__()
 
     def get_vector_store_endpoints_by_type(self) -> VectorStoreIndexEndpoints:
+        """
+        Every ``GET`` under ``/indexes/`` is a read: get details, stats, and the
+        document reads (GET-form search, ``$count``, point lookup, and the
+        GET forms of suggest and autocomplete).
+
+        ``POST`` splits by endpoint. Search, suggest, autocomplete, and analyze
+        are query endpoints, so they read; ``/docs/index`` is the batch endpoint
+        carrying upload, merge, mergeOrUpload, and delete actions, so it writes.
+
+        Patterns stay literal rather than ``{placeholder}`` templates because the
+        matcher falls back to the substring before a ``{``, which here is always
+        ``/indexes/``. The matcher is substring-based, so an index name may
+        itself contain a read fragment (an index named ``analyze*`` puts
+        ``/analyze`` inside the batch-write path); writes are classified before
+        reads, so such a path demands the write grant rather than being
+        shadowed into a read.
+        """
         return {
-            "read": [("GET", "/docs/search"), ("POST", "/docs/search")],
-            "write": [("PUT", "/docs")],
+            "read": [
+                ("GET", "/indexes/"),
+                ("POST", "/docs/search"),
+                ("POST", "/docs/suggest"),
+                ("POST", "/docs/autocomplete"),
+                ("POST", "/analyze"),
+            ],
+            "write": [("POST", "/docs/index")],
         }
 
     def get_auth_credentials(self, litellm_params: dict) -> BaseVectorStoreAuthCredentials:
diff --git a/litellm/llms/base_llm/search/transformation.py b/litellm/llms/base_llm/search/transformation.py
index 6987e261d4e..dee67e0b100 100644
--- a/litellm/llms/base_llm/search/transformation.py
+++ b/litellm/llms/base_llm/search/transformation.py
@@ -18,6 +18,16 @@ else:
     LiteLLMLoggingObj = Any
 
 
+_PERPLEXITY_UNIFIED_PARAMS: Final[frozenset[str]] = frozenset(
+    (
+        "max_results",
+        "search_domain_filter",
+        "country",
+        "max_tokens_per_page",
+    )
+)
+
+
 def _search_host(url: str) -> str:
     return urlsplit(url).netloc.lower()
 
@@ -96,7 +106,7 @@ class BaseSearchConfig:
         return "POST"
 
     @staticmethod
-    def get_supported_perplexity_optional_params() -> set:
+    def get_supported_perplexity_optional_params() -> frozenset[str]:
         """
         Get the set of Perplexity unified search parameters.
         These are the standard parameters that providers should transform from.
@@ -104,12 +114,7 @@ class BaseSearchConfig:
         Returns:
             Set of parameter names that are part of the unified spec
         """
-        return {
-            "max_results",
-            "search_domain_filter",
-            "country",
-            "max_tokens_per_page",
-        }
+        return _PERPLEXITY_UNIFIED_PARAMS
 
     def _assert_trusted_api_base_for_server_credential(
         self,
diff --git a/litellm/llms/nimble/__init__.py b/litellm/llms/nimble/__init__.py
new file mode 100644
index 00000000000..05272cb1230
--- /dev/null
+++ b/litellm/llms/nimble/__init__.py
@@ -0,0 +1,3 @@
+from litellm.llms.nimble.search.transformation import NimbleSearchConfig
+
+__all__ = ("NimbleSearchConfig",)
diff --git a/litellm/llms/nimble/search/__init__.py b/litellm/llms/nimble/search/__init__.py
new file mode 100644
index 00000000000..05272cb1230
--- /dev/null
+++ b/litellm/llms/nimble/search/__init__.py
@@ -0,0 +1,3 @@
+from litellm.llms.nimble.search.transformation import NimbleSearchConfig
+
+__all__ = ("NimbleSearchConfig",)
diff --git a/litellm/llms/nimble/search/transformation.py b/litellm/llms/nimble/search/transformation.py
new file mode 100644
index 00000000000..7485686d230
--- /dev/null
+++ b/litellm/llms/nimble/search/transformation.py
@@ -0,0 +1,264 @@
+"""
+Calls Nimble's /v2/search endpoint to search the web.
+
+Nimble API Reference: https://docs.nimbleway.com/api-reference/search/search
+"""
+
+from __future__ import annotations
+
+from collections.abc import Mapping
+from types import MappingProxyType
+from typing import TYPE_CHECKING, Final
+
+import httpx
+from pydantic import BaseModel, ConfigDict, TypeAdapter, ValidationError
+
+from litellm.llms.base_llm.chat.transformation import BaseLLMException
+from litellm.llms.base_llm.search.transformation import (
+    BaseSearchConfig,
+    SearchResponse,
+    SearchResult,
+)
+from litellm.secret_managers.main import get_secret_str
+
+if TYPE_CHECKING:
+    from litellm.litellm_core_utils.litellm_logging import Logging as LiteLLMLoggingObj
+
+_NIMBLE_DOCS_URL: Final = "https://docs.nimbleway.com/api-reference/search/search"
+
+
+class _NimbleResult(BaseModel):
+    """One entry of Nimble's `results` array. Every field is optional so a single degraded
+    result degrades to empty strings instead of failing the whole call."""
+
+    model_config = ConfigDict(extra="ignore", frozen=True)
+
+    title: str | None = None
+    url: str | None = None
+    content: str | None = None
+    description: str | None = None
+    # Free-form per Nimble's schema, so an unexpected shape must not fail the search.
+    additional_data: object = None
+
+
+class _NimbleSearchResponse(BaseModel):
+    """Nimble's /v2/search response envelope."""
+
+    model_config = ConfigDict(extra="ignore", frozen=True)
+
+    # Required: a search with no hits returns `[]`, so a null or absent `results` means the
+    # body is not a search response and must not be reported as a successful empty search.
+    results: tuple[_NimbleResult, ...]
+
+
+class _AdditionalData(BaseModel):
+    """The slice of a result's free-form `additional_data` that maps onto SearchResult."""
+
+    model_config = ConfigDict(extra="ignore", frozen=True)
+
+    publish_date: str | None = None
+
+
+class _ErrorEnvelope(BaseModel):
+    """Nimble reports errors as either `{"detail": ...}` (validation) or
+    `{"success": "false", "task_id": ..., "message": ...}` (collection)."""
+
+    model_config = ConfigDict(extra="ignore", frozen=True)
+
+    detail: str | None = None
+    message: str | None = None
+
+
+_DomainListAdapter: Final = TypeAdapter(tuple[str, ...])
+
+_NOTHING: Final[Mapping[str, object]] = MappingProxyType({})
+
+
+def _optional(key: str, value: object) -> Mapping[str, object]:
+    """A one-entry mapping to spread into a payload, or nothing when the value is absent."""
+    return MappingProxyType({key: value}) if value is not None else _NOTHING
+
+
+class NimbleSearchConfig(BaseSearchConfig):
+    NIMBLE_API_BASE = "https://sdk.nimbleway.com/v2"
+
+    @staticmethod
+    def ui_friendly_name() -> str:
+        return "Nimble"
+
+    def validate_environment(
+        self,
+        headers: dict[str, str],  # mutable-ok: BaseSearchConfig.validate_environment signature
+        api_key: str | None = None,
+        api_base: str | None = None,
+        **kwargs: object,  # kwargs-ok: BaseSearchConfig.validate_environment signature
+    ) -> dict[str, str]:  # mutable-ok: the http handler passes this straight to httpx as headers
+        """
+        Validate environment and return headers.
+
+        Returns a new dict rather than mutating ``headers``: the http handler calls this
+        a second time after ``litellm/search/main.py`` already did, so it has to be idempotent.
+        """
+        resolved_api_key: Final = self.resolve_server_api_key(
+            caller_api_key=api_key,
+            caller_api_base=api_base,
+            key_env_vars=("NIMBLE_API_KEY",),
+            base_env_var="NIMBLE_API_BASE",
+            default_api_base=self.NIMBLE_API_BASE,
+        )
+        if not resolved_api_key:
+            raise ValueError("NIMBLE_API_KEY is not set. Set `NIMBLE_API_KEY` environment variable.")
+        return {  # mutable-ok: httpx requires a plain dict of headers
+            **headers,
+            "Authorization": f"Bearer {resolved_api_key}",
+            "Content-Type": "application/json",
+            # Nimble's client-attribution header: names the calling software, nothing else.
+            "X-Client-Source": "litellm",
+        }
+
+    def get_complete_url(
+        self,
+        api_base: str | None,
+        optional_params: dict[str, object],  # mutable-ok: BaseSearchConfig.get_complete_url signature
+        data: dict[str, object] | list[dict[str, object]] | None = None,  # mutable-ok: base signature
+        **kwargs: object,  # kwargs-ok: BaseSearchConfig.get_complete_url signature
+    ) -> str:
+        resolved_base: Final = (api_base or get_secret_str("NIMBLE_API_BASE") or self.NIMBLE_API_BASE).rstrip("/")
+        if resolved_base.endswith("/search"):
+            return resolved_base
+        return f"{resolved_base}/search"
+
+    def transform_search_request(
+        self,
+        query: str | list[str],  # mutable-ok: BaseSearchConfig.transform_search_request signature
+        optional_params: dict[str, object],  # mutable-ok: base signature
+        **kwargs: object,  # kwargs-ok: BaseSearchConfig.transform_search_request signature
+    ) -> dict[str, object]:  # mutable-ok: the http handler passes this straight to httpx as the JSON body
+        """
+        Transform Search request to Nimble API format.
+
+        Nimble already uses the Perplexity unified spec's names, so this is close to a pass-through:
+        - query -> query (a list is joined with spaces; Nimble takes a single string)
+        - max_results -> max_results (sent unclamped so Nimble's own 1-100 validation reports the error)
+        - country -> country, upper-cased to the ISO form Nimble documents
+        - search_domain_filter -> include_domains, with `-`-prefixed entries going to exclude_domains
+        - max_tokens_per_page -> dropped (no Nimble equivalent)
+
+        Everything else is forwarded as-is, so the rest of Nimble's surface stays reachable
+        without LiteLLM tracking it.
+        """
+        unified_params: Final = self.get_supported_perplexity_optional_params()
+        country: Final = optional_params.get("country")
+
+        # Spread after the derived domain filters so an explicitly supplied `include_domains`
+        # or `exclude_domains` wins over anything read out of `search_domain_filter`.
+        passthrough: Final = MappingProxyType(
+            {param: value for param, value in optional_params.items() if param not in unified_params}
+        )
+
+        return {  # mutable-ok: httpx requires a plain dict for the JSON body
+            **_domain_filters(optional_params.get("search_domain_filter")),
+            **passthrough,
+            "query": " ".join(query) if isinstance(query, list) else query,
+            **_optional("max_results", optional_params.get("max_results")),
+            **_optional("country", country.upper() if isinstance(country, str) else None),
+        }
+
+    def transform_search_response(
+        self,
+        raw_response: httpx.Response,
+        logging_obj: LiteLLMLoggingObj,
+        **kwargs: object,  # kwargs-ok: BaseSearchConfig.transform_search_response signature
+    ) -> SearchResponse:
+        """
+        Transform Nimble API response to LiteLLM unified SearchResponse format.
+
+        `date` carries only the absolute `publish_date`. News results often carry a relative
+        `publish_date_raw` ("1 day ago") instead, which is not a date, so the whole
+        `additional_data` object rides through as an extra on `SearchResult` and nothing is lost.
+
+        Nimble ranks results itself via metadata.position, so the order is preserved as received.
+        A body that does not match the documented schema raises an attributed error rather than
+        being reported as a successful empty search. Parsing the response bytes rather than
+        `.json()` covers the non-JSON case through that same path.
+        """
+        try:
+            parsed: Final = _NimbleSearchResponse.model_validate_json(raw_response.content)
+        except ValidationError as e:
+            raise self.get_error_class(
+                error_message=f"response does not match the documented /v2/search schema: {e}",
+                status_code=raw_response.status_code,
+                headers=dict(raw_response.headers),  # mutable-ok: BaseSearchConfig.get_error_class signature
+            )
+
+        return SearchResponse(
+            results=[  # mutable-ok: SearchResponse.results is declared list[SearchResult]
+                SearchResult(
+                    title=result.title or "",
+                    url=result.url or "",
+                    snippet=result.content or result.description or "",
+                    date=_publish_date(result.additional_data),
+                    last_updated=None,
+                    **_optional("additional_data", result.additional_data),
+                )
+                for result in parsed.results
+            ],
+            object="search",
+        )
+
+    def get_error_class(
+        self,
+        error_message: str,
+        status_code: int,
+        headers: dict[str, str],  # mutable-ok: BaseSearchConfig.get_error_class signature
+    ) -> Exception:
+        detail: Final = _unwrap_error_detail(error_message).rstrip(". ")
+        return BaseLLMException(
+            status_code=status_code,
+            message=f"Nimble Search: {detail}. See {_NIMBLE_DOCS_URL} for details.",
+            headers=headers,
+        )
+
+
+def _unwrap_error_detail(error_message: str) -> str:
+    """
+    Surface the human-readable message inside Nimble's error envelopes.
+
+    Falls back to the raw body for anything else (CDN HTML pages, plain text, other shapes).
+    """
+    try:
+        body: Final = _ErrorEnvelope.model_validate_json(error_message)
+    except ValidationError:
+        return error_message
+    return body.detail or body.message or error_message
+
+
+def _domain_filters(search_domain_filter: object) -> Mapping[str, object]:
+    """
+    Split the unified `search_domain_filter` into Nimble's include/exclude lists.
+
+    Follows the Perplexity unified spec, where a `-` prefix means "exclude this domain".
+    Anything that is not a list of strings is ignored rather than raising, since it only
+    ever narrows a search that is otherwise valid.
+    """
+    try:
+        domains: Final = _DomainListAdapter.validate_python(search_domain_filter)
+    except ValidationError:
+        return _NOTHING
+    return MappingProxyType(
+        {
+            key: value
+            for key, value in (
+                ("include_domains", tuple(d for d in domains if d and not d.startswith("-"))),
+                ("exclude_domains", tuple(d[1:] for d in domains if d.startswith("-") and len(d) > 1)),
+            )
+            if value
+        }
+    )
+
+
+def _publish_date(additional_data: object) -> str | None:
+    try:
+        return _AdditionalData.model_validate(additional_data).publish_date
+    except ValidationError:
+        return None
diff --git a/litellm/model_prices_and_context_window_backup.json b/litellm/model_prices_and_context_window_backup.json
index b288269b0a2..0eb9f6119ff 100644
--- a/litellm/model_prices_and_context_window_backup.json
+++ b/litellm/model_prices_and_context_window_backup.json
@@ -16295,6 +16295,14 @@
             "notes": "TinyFish Search API"
         }
     },
+    "nimble/search": {
+        "input_cost_per_query": 0.005,
+        "litellm_provider": "nimble",
+        "mode": "search",
+        "metadata": {
+            "notes": "Nimble Search API pay-as-you-go list price: $5 per 1,000 searches, up to 100 results per search. Volume plans price differently."
+        }
+    },
     "elevenlabs/scribe_v1": {
         "input_cost_per_second": 6.11e-05,
         "litellm_provider": "elevenlabs",
diff --git a/litellm/proxy/_experimental/mcp_server/utils.py b/litellm/proxy/_experimental/mcp_server/utils.py
index 4cf84dd0725..83883664df5 100644
--- a/litellm/proxy/_experimental/mcp_server/utils.py
+++ b/litellm/proxy/_experimental/mcp_server/utils.py
@@ -880,7 +880,9 @@ _HOP_BY_HOP_HEADERS: Final = frozenset(
     }
 )
 
-_SYNTHETIC_REQUEST_EXCLUDED_HEADERS: Final = _HOP_BY_HOP_HEADERS | frozenset({"content-type", "x-forwarded-for"})
+_SYNTHETIC_REQUEST_EXCLUDED_HEADERS: Final = _HOP_BY_HOP_HEADERS | frozenset(
+    {"content-type", "host", "x-forwarded-for"}
+)
 
 _SYNTHETIC_REQUEST_SERVER: Final = ("127.0.0.1", 4000)
 
@@ -908,10 +910,57 @@ def _mcp_client_side_auth_header_name() -> str:
         return MCPRequestHandler.LITELLM_MCP_AUTH_HEADER_NAME
 
 
+def _identity_header_names() -> frozenset[str]:
+    """Lowercased header names the deployment reads the caller's identity out of. A name here
+    is a claim about who the caller is rather than a secret, and ``get_user_from_headers``
+    resolves it off the request this module reconstructs, so dropping one would lose end user
+    attribution on the MCP paths that leave ``end_user_id`` unset at connect time.
+
+    ``user_header_mappings`` is accepted as a bare mapping as well as a list of them, matching
+    ``get_internal_user_header_from_mapping`` and ``get_customer_user_header_from_mapping``.
+    Iterating the bare form without normalizing yields its keys, which would silently exempt
+    nothing."""
+    try:
+        from litellm.proxy.proxy_server import general_settings
+    except ImportError:
+        return frozenset()
+    if not general_settings:
+        return frozenset()
+    user_header: Final = general_settings.get("user_header_name")
+    configured: Final = general_settings.get("user_header_mappings")
+    mappings: Final = configured if isinstance(configured, list) else (configured,) if configured else ()
+    mapped: Final = (mapping.get("header_name") for mapping in mappings if isinstance(mapping, Mapping))
+    return frozenset(name.lower() for name in (user_header, *mapped) if isinstance(name, str) and name)
+
+
+def _forwarded_upstream_header_names() -> frozenset[str]:
+    """Lowercased header names that a configured MCP server forwards upstream through its
+    ``extra_headers`` allowlist. The names are chosen by the admin, so no prefix rule can
+    recognize them, and a caller supplied value under one of them is an upstream credential.
+
+    ``authorization`` is left out because ``clean_headers`` already strips it, and claiming it
+    here would change which header ``authenticated_with_header`` resolves to on the oauth
+    passthrough config, which lists it in ``extra_headers`` by design. Identity headers are
+    left out for the same reason: naming one in ``extra_headers`` forwards the caller's
+    identity upstream, it does not turn that identity into a secret."""
+    try:
+        from .mcp_server_manager import global_mcp_server_manager
+    except ImportError:
+        return frozenset()
+    exempt: Final = _identity_header_names() | frozenset({"authorization"})
+    return frozenset(
+        name.lower()
+        for server in global_mcp_server_manager.get_registry().values()
+        for name in (server.extra_headers or ())
+        if name.lower() not in exempt
+    )
+
+
 def _upstream_credential_headers(header_names: Iterable[str]) -> frozenset[str]:
     """Lowercased names of the headers in ``header_names`` that carry an upstream MCP
-    credential rather than request context: the configured client side auth header and
-    the per-server ``x-mcp-{alias}-{header}`` family. ``clean_headers`` only knows the
+    credential rather than request context: the configured client side auth header, any
+    header name a configured server forwards upstream via ``extra_headers``, and the
+    per-server ``x-mcp-{alias}-{header}`` family. ``clean_headers`` only knows the
     credential headers of the chat completions path, so these are dropped on top of it.
     """
     from .auth.user_api_key_auth_mcp import MCPRequestHandler
@@ -923,10 +972,13 @@ def _upstream_credential_headers(header_names: Iterable[str]) -> frozenset[str]:
         }
     )
     client_side_auth: Final = _mcp_client_side_auth_header_name().lower()
+    forwarded_upstream: Final = _forwarded_upstream_header_names()
     return frozenset(
         name
         for name in (raw_name.lower() for raw_name in header_names)
-        if name == client_side_auth or (name.startswith(_MCP_SERVER_AUTH_HEADER_PREFIX) and name not in non_credential)
+        if name == client_side_auth
+        or name in forwarded_upstream
+        or (name.startswith(_MCP_SERVER_AUTH_HEADER_PREFIX) and name not in non_credential)
     )
 
 
@@ -944,7 +996,9 @@ def build_synthetic_mcp_request(
     ``proxy_server_request``, header-based tags, guardrails and trace correlation
     exactly as on the chat completions path. Hop-by-hop headers describe the
     original HTTP framing rather than the logical request, so they are dropped, and
-    ``x-forwarded-for`` comes from the resolved ``client_ip`` to avoid spoofing. Upstream
+    ``x-forwarded-for`` comes from the resolved ``client_ip`` to avoid spoofing. ``host`` is
+    dropped for the same reason: it is what ``Request.url`` is built from, so forwarding it
+    would let a caller choose the URL every logging callback records. Upstream
     MCP credentials and the deployment's proxy key header, including a custom
     ``litellm_key_header_name``, are dropped so they cannot reach a callback or a guardrail
     through the derived metadata even when a caller omits ``general_settings``.
@@ -991,7 +1045,8 @@ def logging_safe_mcp_headers(raw_headers: Mapping[str, str] | None) -> Mapping[s
     too: these headers are read back out of the metadata to change proxy behaviour, so
     leaving one in place would let any MCP client turn off the redaction an admin
     configured. This path carries no key or team object to authorize an opt-out with, so
-    it always strips them."""
+    it always strips them. ``host`` goes too, so that a caller cannot name the deployment in
+    the guardrail payload and the spend row the way it could once name the request URL."""
     from starlette.datastructures import Headers
 
     from litellm.proxy.litellm_pre_call_utils import (
@@ -1003,6 +1058,7 @@ def logging_safe_mcp_headers(raw_headers: Mapping[str, str] | None) -> Mapping[s
     excluded: Final = (
         _upstream_credential_headers(raw_headers.keys() if raw_headers else ())
         | UNTRUSTED_REQUEST_HEADER_CONTROL_FIELDS
+        | frozenset({"host"})
     )
     cleaned: Final = clean_headers(
         Headers(raw_headers),
diff --git a/litellm/proxy/db/db_spend_update_writer.py b/litellm/proxy/db/db_spend_update_writer.py
index b2b72c1cac4..471067b16f8 100644
--- a/litellm/proxy/db/db_spend_update_writer.py
+++ b/litellm/proxy/db/db_spend_update_writer.py
@@ -861,6 +861,8 @@ class DBSpendUpdateWriter:
         ):
             verbose_proxy_logger.debug("acquired lock for spend updates")
 
+            uncommitted: dict[str, Any] = {}  # mutable-ok: tracks popped categories still needing commit
+
             try:
                 (
                     db_spend_update_transactions,
@@ -871,6 +873,15 @@ class DBSpendUpdateWriter:
                     daily_agent_spend_update_transactions,
                 ) = await self.redis_update_buffer.get_all_transactions_from_redis_buffer_pipeline()
 
+                uncommitted = {  # mutable-ok: drives which popped categories still need re-queuing
+                    "db_spend_update_transactions": db_spend_update_transactions,
+                    "daily_spend_update_transactions": daily_spend_update_transactions,
+                    "daily_team_spend_update_transactions": daily_team_spend_update_transactions,
+                    "daily_org_spend_update_transactions": daily_org_spend_update_transactions,
+                    "daily_end_user_spend_update_transactions": daily_end_user_spend_update_transactions,
+                    "daily_agent_spend_update_transactions": daily_agent_spend_update_transactions,
+                }
+
                 if db_spend_update_transactions is not None:
                     verbose_proxy_logger.info(
                         "Spend tracking - committing spend updates from Redis to DB: "
@@ -890,6 +901,7 @@ class DBSpendUpdateWriter:
                         proxy_logging_obj=proxy_logging_obj,
                         db_spend_update_transactions=db_spend_update_transactions,
                     )
+                uncommitted.pop("db_spend_update_transactions", None)
 
                 if daily_spend_update_transactions is not None:
                     await DBSpendUpdateWriter.update_daily_user_spend(
@@ -898,6 +910,8 @@ class DBSpendUpdateWriter:
                         proxy_logging_obj=proxy_logging_obj,
                         daily_spend_transactions=daily_spend_update_transactions,
                     )
+                uncommitted.pop("daily_spend_update_transactions", None)
+
                 if daily_team_spend_update_transactions is not None:
                     await DBSpendUpdateWriter.update_daily_team_spend(
                         n_retry_times=n_retry_times,
@@ -905,6 +919,7 @@ class DBSpendUpdateWriter:
                         proxy_logging_obj=proxy_logging_obj,
                         daily_spend_transactions=daily_team_spend_update_transactions,
                     )
+                uncommitted.pop("daily_team_spend_update_transactions", None)
 
                 if daily_org_spend_update_transactions is not None:
                     await DBSpendUpdateWriter.update_daily_org_spend(
@@ -913,6 +928,7 @@ class DBSpendUpdateWriter:
                         proxy_logging_obj=proxy_logging_obj,
                         daily_spend_transactions=daily_org_spend_update_transactions,
                     )
+                uncommitted.pop("daily_org_spend_update_transactions", None)
 
                 if daily_end_user_spend_update_transactions is not None:
                     await DBSpendUpdateWriter.update_daily_end_user_spend(
@@ -921,6 +937,8 @@ class DBSpendUpdateWriter:
                         proxy_logging_obj=proxy_logging_obj,
                         daily_spend_transactions=daily_end_user_spend_update_transactions,
                     )
+                uncommitted.pop("daily_end_user_spend_update_transactions", None)
+
                 if daily_agent_spend_update_transactions is not None:
                     await DBSpendUpdateWriter.update_daily_agent_spend(
                         n_retry_times=n_retry_times,
@@ -928,14 +946,20 @@ class DBSpendUpdateWriter:
                         proxy_logging_obj=proxy_logging_obj,
                         daily_spend_transactions=daily_agent_spend_update_transactions,
                     )
+                uncommitted.pop("daily_agent_spend_update_transactions", None)
             except Exception as e:
                 spend_log_error(
                     "Spend tracking - failed to commit spend updates from Redis to DB. "
-                    "Data already popped from Redis may be lost. Error: %s",
+                    "Re-queuing uncommitted transactions to Redis for retry on next tick. Error: %s",
                     str(e),
                     exc=e,
                 )
             finally:
+                to_restore = {  # mutable-ok: transient kwargs payload consumed immediately below
+                    name: txns for name, txns in uncommitted.items() if txns is not None
+                }
+                if to_restore:
+                    await self.redis_update_buffer.restore_transactions_to_redis(**to_restore)
                 await self.pod_lock_manager.release_lock(
                     cronjob_id=DB_SPEND_UPDATE_JOB_NAME,
                 )
@@ -1085,21 +1109,15 @@ class DBSpendUpdateWriter:
         ):
             verbose_proxy_logger.debug("acquired lock for daily tag spend updates")
             try:
-                daily_tag_spend_update_transactions: Final = (
-                    await self.redis_update_buffer.get_all_daily_tag_spend_update_transactions_from_redis_buffer()
+                await self._drain_and_commit_daily_tag_spend_from_redis(
+                    prisma_client=prisma_client,
+                    n_retry_times=n_retry_times,
+                    proxy_logging_obj=proxy_logging_obj,
                 )
-
-                if daily_tag_spend_update_transactions:
-                    await DBSpendUpdateWriter.update_daily_tag_spend(
-                        n_retry_times=n_retry_times,
-                        prisma_client=prisma_client,
-                        proxy_logging_obj=proxy_logging_obj,
-                        daily_spend_transactions=daily_tag_spend_update_transactions,
-                    )
             except Exception as e:
                 spend_log_error(
                     "Spend tracking - failed to commit daily tag spend updates from Redis to DB. "
-                    "Data already popped from Redis may be lost. Error: %s",
+                    "Re-queuing to Redis for retry on next tick. Error: %s",
                     str(e),
                     exc=e,
                 )
@@ -1108,6 +1126,37 @@ class DBSpendUpdateWriter:
                     cronjob_id=DB_DAILY_TAG_SPEND_UPDATE_JOB_NAME,
                 )
 
+    async def _drain_and_commit_daily_tag_spend_from_redis(
+        self,
+        prisma_client: PrismaClient,
+        n_retry_times: int,
+        proxy_logging_obj: ProxyLogging,
+    ) -> None:
+        """
+        Drain the Redis tag spend buffer and commit it, restoring the drained transactions if the commit fails.
+
+        The drain is destructive, so a failed commit must push the transactions back for the next tick
+        or their spend is lost permanently.
+        """
+        daily_tag_spend_update_transactions: Final = (
+            await self.redis_update_buffer.get_all_daily_tag_spend_update_transactions_from_redis_buffer()
+        )
+        if not daily_tag_spend_update_transactions:
+            return
+
+        try:
+            await DBSpendUpdateWriter.update_daily_tag_spend(
+                n_retry_times=n_retry_times,
+                prisma_client=prisma_client,
+                proxy_logging_obj=proxy_logging_obj,
+                daily_spend_transactions=daily_tag_spend_update_transactions,
+            )
+        except Exception:
+            await self.redis_update_buffer.restore_transactions_to_redis(
+                daily_tag_spend_update_transactions=daily_tag_spend_update_transactions,
+            )
+            raise
+
     async def _flush_tool_discovery_queue(
         self,
         prisma_client: PrismaClient,
@@ -1607,9 +1656,6 @@ class DBSpendUpdateWriter:
                         )
 
         except Exception as e:
-            if "transactions_to_process" in locals():
-                for key in transactions_to_process:
-                    daily_spend_transactions.pop(key, None)
             _raise_failed_update_spend_exception(e=e, start_time=start_time, proxy_logging_obj=proxy_logging_obj)
 
     @staticmethod
diff --git a/litellm/proxy/db/db_transaction_queue/redis_update_buffer.py b/litellm/proxy/db/db_transaction_queue/redis_update_buffer.py
index 6879284a6fd..853c033c37e 100644
--- a/litellm/proxy/db/db_transaction_queue/redis_update_buffer.py
+++ b/litellm/proxy/db/db_transaction_queue/redis_update_buffer.py
@@ -6,8 +6,11 @@ This is to prevent deadlocks and improve reliability
 
 import asyncio
 import json
+from collections.abc import Mapping
 from typing import TYPE_CHECKING, Any, Final, cast
 
+from redis.exceptions import RedisError
+
 from litellm._logging import verbose_proxy_logger
 from litellm.caching import RedisCache
 from litellm.constants import (
@@ -372,6 +375,59 @@ class RedisUpdateBuffer:
             if daily_txns:
                 await daily_queue.update_queue.put(daily_txns)
 
+    async def restore_transactions_to_redis(
+        self,
+        db_spend_update_transactions: DBSpendUpdateTransactions | None = None,
+        daily_spend_update_transactions: Mapping[str, BaseDailySpendTransaction] | None = None,
+        daily_team_spend_update_transactions: Mapping[str, BaseDailySpendTransaction] | None = None,
+        daily_org_spend_update_transactions: Mapping[str, BaseDailySpendTransaction] | None = None,
+        daily_end_user_spend_update_transactions: Mapping[str, BaseDailySpendTransaction] | None = None,
+        daily_agent_spend_update_transactions: Mapping[str, BaseDailySpendTransaction] | None = None,
+        daily_tag_spend_update_transactions: Mapping[str, BaseDailySpendTransaction] | None = None,
+    ) -> None:
+        """
+        Re-push transactions that were popped from Redis but not committed to the DB.
+
+        The leader drains the buffers with a destructive ``lpop`` before committing to
+        the database. When a commit fails after its retries are exhausted, the popped
+        transactions must be pushed back so a later scheduler tick can retry them;
+        otherwise the aggregated spend is lost permanently. The re-pushed payloads use
+        the same JSON encoding as the store path, so the next drain parses them normally.
+        """
+        if self.redis_cache is None:
+            return
+
+        restore_configs: Final = (
+            (db_spend_update_transactions, REDIS_UPDATE_BUFFER_KEY),
+            (daily_spend_update_transactions, REDIS_DAILY_SPEND_UPDATE_BUFFER_KEY),
+            (daily_team_spend_update_transactions, REDIS_DAILY_TEAM_SPEND_UPDATE_BUFFER_KEY),
+            (daily_org_spend_update_transactions, REDIS_DAILY_ORG_SPEND_UPDATE_BUFFER_KEY),
+            (daily_end_user_spend_update_transactions, REDIS_DAILY_END_USER_SPEND_UPDATE_BUFFER_KEY),
+            (daily_agent_spend_update_transactions, REDIS_DAILY_AGENT_SPEND_UPDATE_BUFFER_KEY),
+            (daily_tag_spend_update_transactions, REDIS_DAILY_TAG_SPEND_UPDATE_BUFFER_KEY),
+        )
+
+        rpush_list: Final = tuple(
+            RedisPipelineRpushOperation(key=redis_key, values=(safe_dumps(transactions),))
+            for transactions, redis_key in restore_configs
+            if transactions
+        )
+        if len(rpush_list) == 0:
+            return
+
+        try:
+            await self.redis_cache.async_rpush_pipeline(rpush_list=rpush_list)
+            verbose_proxy_logger.info(
+                "Spend tracking - restored %d uncommitted transaction set(s) to Redis for retry on next tick.",
+                len(rpush_list),
+            )
+        except RedisError as e:
+            verbose_proxy_logger.error(
+                "Spend tracking - failed to restore uncommitted transactions to Redis. "
+                "These spend updates are lost. Error: %s",
+                str(e),
+            )
+
     @staticmethod
     def _number_of_transactions_to_store_in_redis(
         db_spend_update_transactions: DBSpendUpdateTransactions,
diff --git a/litellm/proxy/management_endpoints/auto_router_endpoints.py b/litellm/proxy/management_endpoints/auto_router_endpoints.py
index cb0e8dba62a..4b2569fa9fa 100644
--- a/litellm/proxy/management_endpoints/auto_router_endpoints.py
+++ b/litellm/proxy/management_endpoints/auto_router_endpoints.py
@@ -464,35 +464,38 @@ def _is_configured_pre_routing_strategy(llm_router: "Router", router_name: str)
     )
 
 
-def _validate_judge_model(llm_router: "Router | None", judge_model: str) -> None:
-    """Reject a judge model the dispatch path cannot resolve, at start rather than as a
-    silently growing error count once the job is already sampling and billing."""
-    if llm_router is not None and _is_configured_pre_routing_strategy(llm_router, judge_model):
+def _validate_plain_model(llm_router: "Router | None", model: str, field_name: str) -> None:
+    """Reject a model the dispatch path cannot resolve, at start rather than as a silently
+    growing error count once the job is already sampling and billing. Both the judge and a
+    reverse job's baseline must be plain models: an auto-router in either slot would
+    re-route per turn, so the comparison would have no fixed arm to attribute results to."""
+    if llm_router is not None and _is_configured_pre_routing_strategy(llm_router, model):
         raise HTTPException(
             status_code=400,
-            detail=f"judge_model '{judge_model}' is an auto-router; the judge must be a plain model",
+            detail=f"{field_name} '{model}' is an auto-router; it must be a plain model",
         )
-    if router_resolves_model(llm_router, judge_model):
+    if router_resolves_model(llm_router, model):
         return
     import litellm
 
     try:
-        litellm.get_llm_provider(model=judge_model)
+        litellm.get_llm_provider(model=model)
     except Exception as e:
         raise HTTPException(
             status_code=400,
             detail=(
-                f"judge_model '{judge_model}' is neither a model configured on this proxy nor a "
+                f"{field_name} '{model}' is neither a model configured on this proxy nor a "
                 "provider-qualified public model name (e.g. 'anthropic/claude-sonnet-5')"
             ),
         ) from e
 
 
 def _is_unique_violation(error: Exception) -> bool:
-    """Whether a Prisma create failed on a unique index. One active job per key lives in
-    a partial unique index (raw SQL in the migration; schema.prisma cannot express partial
-    indexes), so the read-then-create check above it is advisory: two concurrent starts
-    pass the read, and the loser must surface as the same 409 rather than a 500."""
+    """Whether a Prisma create failed on a unique index. One active job per key and
+    direction lives in a partial unique index (raw SQL in the migration; schema.prisma
+    cannot express partial indexes), so the read-then-create check above it is advisory:
+    two concurrent starts pass the read, and the loser must surface as the same 409
+    rather than a 500."""
     try:
         from prisma.errors import UniqueViolationError
     except ImportError:
@@ -573,8 +576,10 @@ def _slices(rows: Sequence[_AttemptAggRow]) -> tuple[ShadowEvalSlice, ...]:
 
 async def _shadow_eval_results(prisma_client: "PrismaClient", job_id: str) -> ShadowEvalResult | None:
     """Both stratifications of one job's verdicts. Tier answers "where does the router do
-    well"; current-model answers "which of the models this key uses today would the router
-    beat". Reads are bounded by the job's own attempts (<= max_turns) via the job_id index."""
+    well"; the model stratification groups by whichever model served the real arm, so it
+    answers "which of the models this key uses today would the router beat" forward, and
+    "for the turns the router sent to X, did X beat the baseline" in reverse. Reads are
+    bounded by the job's own attempts (<= max_turns) via the job_id index."""
     by_tier: Final = _ATTEMPT_AGG_ROWS.validate_python(
         await prisma_client.db.query_raw(_ATTEMPT_AGG_BY_TIER_SQL, job_id) or ()
     )
@@ -604,9 +609,15 @@ async def start_shadow_eval(
     user_api_key_dict: Annotated[UserAPIKeyAuth, Depends(user_api_key_auth)],
 ) -> ShadowEvalJobResponse:
     """
-    Start a pre-adoption shadow eval: duplicate a sampled slice of a key's live traffic
-    through an auto-router, judge real vs. shadow responses blind, and stratify win rates
-    by the router's tier classification and by the incumbent model.
+    Start a shadow eval: duplicate a sampled slice of a key's live traffic against a second
+    arm, judge the two responses blind, and stratify win rates by tier and by the model that
+    served the real arm.
+
+    A forward job answers whether the key should adopt router_name: it samples the requests
+    the router did not serve and duplicates them through it. A reverse job answers whether a
+    key already on the router still gains from it: it samples the requests the router did
+    serve and duplicates them against baseline_model. A key can hold one active job per
+    direction, so both questions can run at once.
 
     Shadow responses are never served to users. The job samples until it has judged
     max_turns turns, reaches the end of its window, or is stopped; sampling changes
@@ -620,7 +631,9 @@ async def start_shadow_eval(
         raise HTTPException(status_code=500, detail=CommonProxyErrors.db_not_connected_error.value)
     if llm_router is None or not _is_configured_pre_routing_strategy(llm_router, data.router_name):
         raise HTTPException(status_code=400, detail=f"'{data.router_name}' is not a configured auto-router")
-    _validate_judge_model(llm_router, data.judge_model)
+    _validate_plain_model(llm_router, data.judge_model, "judge_model")
+    if data.baseline_model is not None:
+        _validate_plain_model(llm_router, data.baseline_model, "baseline_model")
     key_row: Final = await prisma_client.db.litellm_verificationtoken.find_unique(
         where={"token": data.api_key_id}  # mutable-ok: Prisma filter
     )
@@ -634,16 +647,20 @@ async def start_shadow_eval(
         )
 
     # A job that expired or exhausted its turn budget stopped sampling on its own, but
-    # still holds the one-active-per-key partial unique index until stamped; free it so
-    # a new eval can start.
+    # still holds its slot in the per-key, per-direction partial unique index until
+    # stamped; free it so a new eval can start. Sweeping both directions is deliberate.
     await prisma_client.db.execute_raw(_SWEEP_FINISHED_JOBS_SQL, data.api_key_id)
     active: Final = await prisma_client.db.litellm_shadowevaljob.find_first(
-        where={"api_key_id": data.api_key_id, "stopped_at": None},  # mutable-ok: Prisma filter
+        where={  # mutable-ok: Prisma filter
+            "api_key_id": data.api_key_id,
+            "direction": data.direction,
+            "stopped_at": None,
+        },
     )
     if active is not None:
         raise HTTPException(
             status_code=409,
-            detail=f"Key already has an active shadow eval job ({active.id}). Stop it first.",
+            detail=f"Key already has an active {data.direction} shadow eval job ({active.id}). Stop it first.",
         )
     now: Final = datetime.now(timezone.utc)
     try:
@@ -651,6 +668,8 @@ async def start_shadow_eval(
             data={  # mutable-ok: Prisma payload
                 "api_key_id": data.api_key_id,
                 "router_name": data.router_name,
+                "direction": data.direction,
+                "baseline_model": data.baseline_model,
                 "judge_model": data.judge_model,
                 "shadow_percentage": data.shadow_percentage,
                 "max_turns": data.max_turns,
@@ -663,7 +682,9 @@ async def start_shadow_eval(
             raise
         raise HTTPException(
             status_code=409,
-            detail="Key already has an active shadow eval job (started concurrently). Stop it first.",
+            detail=(
+                f"Key already has an active {data.direction} shadow eval job (started concurrently). Stop it first."
+            ),
         ) from e
     return ShadowEvalJobResponse.model_validate(job, from_attributes=True)
 
diff --git a/litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py b/litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py
index f84cdd0c222..8c76b9d4e1b 100644
--- a/litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py
+++ b/litellm/proxy/pass_through_endpoints/llm_passthrough_endpoints.py
@@ -44,6 +44,7 @@ from litellm.proxy.pass_through_endpoints.pass_through_endpoints import (
 )
 from litellm.proxy.utils import is_known_model
 from litellm.proxy.vector_store_endpoints.utils import (
+    assert_proxy_admin_for_vector_store_index_management,
     assert_user_can_access_vector_store,
     get_litellm_managed_vector_store,
     is_allowed_to_call_vector_store_endpoint,
@@ -1234,6 +1235,37 @@ async def assemblyai_proxy_route(
     return received_value
 
 
+def get_azure_ai_search_index_from_endpoint(endpoint: str) -> str | None:
+    """Return the index name in the ``/indexes/{name}`` position of an Azure AI
+    Search passthrough path, or ``None`` when the path targets no index.
+
+    Only the segment immediately after ``indexes`` is the operable target. Any
+    other segment (for example the trailing ``index`` in ``.../docs/index``) must
+    never be treated as the index, otherwise a caller authorized on one index
+    could have Azure apply the operation to a different index on the same service.
+    """
+    segments: Final = endpoint.split("?", 1)[0].strip("/").split("/")
+    for position, segment in enumerate(segments):
+        if segment == "indexes" and position + 1 < len(segments):
+            return segments[position + 1] or None
+    return None
+
+
+def is_azure_ai_search_service_level_index_create(method: str, endpoint: str) -> bool:
+    """Return True for ``POST /indexes``, Azure AI Search's service-level index create.
+
+    No index name appears in that path, so ``get_azure_ai_search_index_from_endpoint``
+    yields None and the managed-index branch can never claim the request. Without an
+    explicit guard it reaches the generic Azure passthrough on the proxy's own
+    credential, so a non-admin could create an index whenever ``AZURE_API_BASE``
+    points at the Search service.
+    """
+    if method != "POST":
+        return False
+    path: Final = endpoint.split("?", 1)[0].strip("/")
+    return path == "indexes" or path.endswith("/indexes")
+
+
 @router.api_route(
     "/azure_ai/{endpoint:path}",
     methods=["GET", "POST", "PUT", "DELETE", "PATCH"],
@@ -1259,10 +1291,15 @@ async def azure_proxy_route(
     """
     from litellm.proxy.proxy_server import llm_router
 
+    if is_azure_ai_search_service_level_index_create(method=request.method, endpoint=endpoint):
+        assert_proxy_admin_for_vector_store_index_management(user_api_key_dict, operation="create")
+
     parts: Final = endpoint.split(
         "/"
     )  # azure model is in the url - e.g. https://{endpoint}/openai/deployments/{deployment-id}/completions?api-version=2024-10-21
 
+    search_index_name: Final = get_azure_ai_search_index_from_endpoint(endpoint)
+
     if len(parts) > 1 and llm_router:
         for part in parts:
             # check if LLM MODEL
@@ -1271,9 +1308,9 @@ async def azure_proxy_route(
             )
             # check if vector store index
             is_vector_store_index = (
-                (litellm.vector_store_index_registry.is_vector_store_index(vector_store_index_name=part))
-                if litellm.vector_store_index_registry is not None
-                else False
+                part == search_index_name
+                and litellm.vector_store_index_registry is not None
+                and litellm.vector_store_index_registry.is_vector_store_index(vector_store_index_name=part)
             )
 
             if is_router_model:
diff --git a/litellm/proxy/schema.prisma b/litellm/proxy/schema.prisma
index 79d778fb464..71345d2ccde 100644
--- a/litellm/proxy/schema.prisma
+++ b/litellm/proxy/schema.prisma
@@ -1450,15 +1450,20 @@ model LiteLLM_AutoRouterSession {
   @@index([last_turn_at], map: "idx_autorouter_session_last_turn")
 }
 
-// Shadow eval: pre-adoption evaluation of an auto-router against a key's live traffic.
-// A sampled slice of requests is duplicated through the router in a detached task and an
-// LLM judge compares real vs shadow responses blind. The job row is immutable config plus
+// Shadow eval: evaluation of an auto-router against a key's live traffic, in either
+// direction. forward duplicates the requests the key did not route through the router
+// through it, answering whether the key should adopt it; reverse duplicates the requests
+// the router did serve against a fixed baseline model, answering whether a key already on
+// it still benefits. Either way a sampled slice runs in a detached task and an LLM judge
+// compares real vs shadow responses blind. The job row is immutable config plus
 // stopped_at; every count, status, and spend figure is derived from the append-only
 // attempt rows, so nothing can disagree across pods or stop races.
 model LiteLLM_ShadowEvalJob {
   id                String   @id @default(cuid())
   api_key_id        String   // hashed virtual key whose traffic is shadowed
-  router_name       String
+  router_name       String   // the auto-router under evaluation, in either direction
+  direction         String   @default("forward") // forward | reverse
+  baseline_model    String?  // reverse only: the fixed model the router is judged against
   judge_model       String
   shadow_percentage Float
   max_turns         Int      // sample budget: judge at most this many turns
diff --git a/litellm/proxy/vector_store_endpoints/utils.py b/litellm/proxy/vector_store_endpoints/utils.py
index 94ba7c06cad..93f1510bf22 100644
--- a/litellm/proxy/vector_store_endpoints/utils.py
+++ b/litellm/proxy/vector_store_endpoints/utils.py
@@ -86,7 +86,7 @@ def _is_vector_store_index_lifecycle_request(
             return True
 
     # POST /indexes (create index at service level; no index name in path).
-    normalized: Final = request_path.rstrip("/")
+    normalized: Final = request_path.split("?", 1)[0].rstrip("/")
     if request_method == "POST" and normalized.endswith("/indexes"):
         return True
 
@@ -387,17 +387,19 @@ def is_allowed_to_call_vector_store_endpoint(
         )
         return True
 
-    # Determine the permission type based on the request
+    # Writes are classified before reads so a path matching both patterns
+    # requires the stronger grant (e.g. the azure batch write on an index
+    # named "analyze*" also contains the "/analyze" read fragment)
     permission_type = None
-    for endpoint in provider_vector_store_endpoints["read"]:
+    for endpoint in provider_vector_store_endpoints["write"]:
         if request.method == endpoint[0] and _does_endpoint_match(endpoint[1], request_route):
-            permission_type = "read"
+            permission_type = "write"
             break
 
     if permission_type is None:
-        for endpoint in provider_vector_store_endpoints["write"]:
+        for endpoint in provider_vector_store_endpoints["read"]:
             if request.method == endpoint[0] and _does_endpoint_match(endpoint[1], request_route):
-                permission_type = "write"
+                permission_type = "read"
                 break
 
     if permission_type is None:
@@ -454,15 +456,15 @@ def is_allowed_to_call_vector_store_files_endpoint(
     request_route: Final = get_request_route(request)
 
     permission_type: str | None = None
-    for endpoint in provider_vector_store_endpoints.get("read", ()):
+    for endpoint in provider_vector_store_endpoints.get("write", ()):
         if request.method == endpoint[0] and _does_endpoint_match(endpoint[1], request_route):
-            permission_type = "read"
+            permission_type = "write"
             break
 
     if permission_type is None:
-        for endpoint in provider_vector_store_endpoints.get("write", ()):
+        for endpoint in provider_vector_store_endpoints.get("read", ()):
             if request.method == endpoint[0] and _does_endpoint_match(endpoint[1], request_route):
-                permission_type = "write"
+                permission_type = "read"
                 break
 
     if permission_type is None:
diff --git a/litellm/types/caching.py b/litellm/types/caching.py
index 6616a2e9bac..427904d2fe2 100644
--- a/litellm/types/caching.py
+++ b/litellm/types/caching.py
@@ -1,3 +1,4 @@
+from collections.abc import Sequence
 from enum import Enum
 from typing import Any, Final, Literal, Optional, Union
 
@@ -59,7 +60,7 @@ class RedisPipelineRpushOperation(TypedDict):
     """
 
     key: str
-    values: list[Any]
+    values: Sequence[Any]
 
 
 class RedisPipelineLpopOperation(TypedDict):
diff --git a/litellm/types/management_endpoints/auto_router_endpoints.py b/litellm/types/management_endpoints/auto_router_endpoints.py
index bf8a3d34098..1b0c7476fc3 100644
--- a/litellm/types/management_endpoints/auto_router_endpoints.py
+++ b/litellm/types/management_endpoints/auto_router_endpoints.py
@@ -6,7 +6,7 @@ from collections.abc import Mapping
 from datetime import datetime, timezone
 from typing import Final, Literal, TypeAlias
 
-from pydantic import AliasChoices, BaseModel, ConfigDict, Field, computed_field, field_validator
+from pydantic import AliasChoices, BaseModel, ConfigDict, Field, computed_field, field_validator, model_validator
 
 from litellm.router_strategy.complexity_router.config import ComplexityRouterConfig
 from litellm.types.utils import StandardLoggingRoutingDecision
@@ -146,11 +146,13 @@ class AutoRouterBenchmarksResponse(BaseModel):
 
 ShadowEvalStatus: TypeAlias = Literal["running", "completed", "stopped"]
 
+ShadowEvalDirection: TypeAlias = Literal["forward", "reverse"]
+
 DEFAULT_SHADOW_EVAL_JUDGE_MODEL: Final[str] = "anthropic/claude-sonnet-5"
 
 
 class StartShadowEvalRequest(BaseModel):
-    """Start shadowing a key's traffic through an auto-router for blind comparison."""
+    """Start duplicating a key's traffic for blind comparison against an auto-router."""
 
     api_key_id: str = Field(
         description=(
@@ -158,7 +160,23 @@ class StartShadowEvalRequest(BaseModel):
             "key's traffic; requests made with any other key are not sampled."
         )
     )
-    router_name: str = Field(description="The auto-router config to shadow requests through")
+    router_name: str = Field(description="The auto-router under evaluation, in either direction")
+    direction: ShadowEvalDirection = Field(
+        default="forward",
+        description=(
+            "forward answers 'should this key adopt router_name': it samples the requests the key did NOT "
+            "route through the router and duplicates them through it. reverse answers 'is the router still "
+            "worth it for a key already on it': it samples the requests the router did serve and duplicates "
+            "them against baseline_model. The response the caller received is always the real arm"
+        ),
+    )
+    baseline_model: str | None = Field(
+        default=None,
+        description=(
+            "Required when direction is reverse and rejected otherwise: the fixed model the router's own "
+            "responses are judged against. Must be a plain model rather than another auto-router"
+        ),
+    )
     shadow_percentage: float = Field(
         ge=0.1,
         le=100.0,
@@ -193,15 +211,33 @@ class StartShadowEvalRequest(BaseModel):
     def _round_percentage(cls, value: float) -> float:
         return round(value, 2)
 
+    @model_validator(mode="after")
+    def _baseline_model_matches_direction(self) -> "StartShadowEvalRequest":
+        if self.direction == "reverse" and self.baseline_model is None:
+            raise ValueError("baseline_model is required when direction is 'reverse'")
+        if self.direction == "forward" and self.baseline_model is not None:
+            raise ValueError("baseline_model is only meaningful when direction is 'reverse'")
+        return self
+
 
 class ShadowEvalSlice(BaseModel):
     """Judge outcomes for one slice of a job's verdicts (a router tier, or one of the
-    models the shadowed key currently uses)."""
+    models that served the real arm)."""
 
     group: str
     turn_count: int
-    real_win_rate_pct: float = Field(description="Share of judged turns where the real (control) model won")
-    shadow_win_rate_pct: float = Field(description="Share of judged turns where the shadowed router's pick won")
+    real_win_rate_pct: float = Field(
+        description=(
+            "Share of judged turns the real arm won, meaning the response the caller actually received: "
+            "the key's own model in forward mode, the router's pick in reverse"
+        )
+    )
+    shadow_win_rate_pct: float = Field(
+        description=(
+            "Share of judged turns the shadow arm won, meaning the duplicated response nobody was served: "
+            "the router's pick in forward mode, baseline_model in reverse"
+        )
+    )
     tie_rate_pct: float
     avg_judge_confidence: float
 
@@ -210,7 +246,12 @@ class ShadowEvalResult(BaseModel):
     """Stratified results of a shadow-eval job's verdicts so far."""
 
     by_tier: tuple[ShadowEvalSlice, ...]
-    by_current_model: tuple[ShadowEvalSlice, ...]
+    by_current_model: tuple[ShadowEvalSlice, ...] = Field(
+        description=(
+            "Sliced by the model that served the real arm: the key's incumbent models in forward mode, "
+            "and in reverse the models the router itself picked"
+        )
+    )
     overall_shadow_win_rate_pct: float
     overall_tie_rate_pct: float
 
@@ -226,6 +267,8 @@ class ShadowEvalJobResponse(BaseModel):
     job_id: str = Field(validation_alias=AliasChoices("id", "job_id"))
     api_key_id: str = Field(description="The hashed virtual key whose traffic this job evaluates, and only that key's")
     router_name: str
+    direction: ShadowEvalDirection = "forward"
+    baseline_model: str | None = None
     judge_model: str
     shadow_percentage: float
     max_turns: int
diff --git a/litellm/types/utils.py b/litellm/types/utils.py
index d9ef538d530..220826ccbca 100644
--- a/litellm/types/utils.py
+++ b/litellm/types/utils.py
@@ -3758,6 +3758,7 @@ class SearchProviders(str, Enum):
     YOU_COM = "you_com"
     APISERPENT = "apiserpent"
     TINYFISH = "tinyfish"
+    NIMBLE = "nimble"
 
 
 # Create a set of all search provider values for quick lookup
diff --git a/litellm/utils.py b/litellm/utils.py
index 79372f00284..f011c1ff62f 100644
--- a/litellm/utils.py
+++ b/litellm/utils.py
@@ -9064,6 +9064,7 @@ class ProviderConfigManager:
         from litellm.llms.firecrawl.search.transformation import FirecrawlSearchConfig
         from litellm.llms.google_pse.search.transformation import GooglePSESearchConfig
         from litellm.llms.linkup.search.transformation import LinkupSearchConfig
+        from litellm.llms.nimble.search.transformation import NimbleSearchConfig
         from litellm.llms.parallel_ai.search.transformation import (
             ParallelAISearchConfig,
         )
@@ -9093,6 +9094,7 @@ class ProviderConfigManager:
             SearchProviders.YOU_COM: YouComSearchConfig,
             SearchProviders.APISERPENT: APISerpentSearchConfig,
             SearchProviders.TINYFISH: TinyfishSearchConfig,
+            SearchProviders.NIMBLE: NimbleSearchConfig,
         }
         config_class: Final = PROVIDER_TO_CONFIG_MAP.get(provider, None)
         if config_class is None:
diff --git a/model_prices_and_context_window.json b/model_prices_and_context_window.json
index b288269b0a2..0eb9f6119ff 100644
--- a/model_prices_and_context_window.json
+++ b/model_prices_and_context_window.json
@@ -16295,6 +16295,14 @@
             "notes": "TinyFish Search API"
         }
     },
+    "nimble/search": {
+        "input_cost_per_query": 0.005,
+        "litellm_provider": "nimble",
+        "mode": "search",
+        "metadata": {
+            "notes": "Nimble Search API pay-as-you-go list price: $5 per 1,000 searches, up to 100 results per search. Volume plans price differently."
+        }
+    },
     "elevenlabs/scribe_v1": {
         "input_cost_per_second": 6.11e-05,
         "litellm_provider": "elevenlabs",
diff --git a/provider_endpoints_support.json b/provider_endpoints_support.json
index 65db63dc045..0712e8e383d 100644
--- a/provider_endpoints_support.json
+++ b/provider_endpoints_support.json
@@ -2423,6 +2423,13 @@
         "search": true
       }
     },
+    "nimble": {
+      "display_name": "Nimble (`nimble`)",
+      "url": "https://docs.nimbleway.com/api-reference/search/search",
+      "endpoints": {
+        "search": true
+      }
+    },
     "triton": {
       "display_name": "Triton (`triton`)",
       "url": "https://docs.litellm.ai/docs/providers/triton-inference-server",
diff --git a/schema.prisma b/schema.prisma
index 79d778fb464..71345d2ccde 100644
--- a/schema.prisma
+++ b/schema.prisma
@@ -1450,15 +1450,20 @@ model LiteLLM_AutoRouterSession {
   @@index([last_turn_at], map: "idx_autorouter_session_last_turn")
 }
 
-// Shadow eval: pre-adoption evaluation of an auto-router against a key's live traffic.
-// A sampled slice of requests is duplicated through the router in a detached task and an
-// LLM judge compares real vs shadow responses blind. The job row is immutable config plus
+// Shadow eval: evaluation of an auto-router against a key's live traffic, in either
+// direction. forward duplicates the requests the key did not route through the router
+// through it, answering whether the key should adopt it; reverse duplicates the requests
+// the router did serve against a fixed baseline model, answering whether a key already on
+// it still benefits. Either way a sampled slice runs in a detached task and an LLM judge
+// compares real vs shadow responses blind. The job row is immutable config plus
 // stopped_at; every count, status, and spend figure is derived from the append-only
 // attempt rows, so nothing can disagree across pods or stop races.
 model LiteLLM_ShadowEvalJob {
   id                String   @id @default(cuid())
   api_key_id        String   // hashed virtual key whose traffic is shadowed
-  router_name       String
+  router_name       String   // the auto-router under evaluation, in either direction
+  direction         String   @default("forward") // forward | reverse
+  baseline_model    String?  // reverse only: the fixed model the router is judged against
   judge_model       String
   shadow_percentage Float
   max_turns         Int      // sample budget: judge at most this many turns
diff --git a/tests/code_coverage_tests/enforce_llms_folder_style.py b/tests/code_coverage_tests/enforce_llms_folder_style.py
index 2cbd445365e..04a95b45196 100644
--- a/tests/code_coverage_tests/enforce_llms_folder_style.py
+++ b/tests/code_coverage_tests/enforce_llms_folder_style.py
@@ -22,6 +22,7 @@ SEARCH_PROVIDERS = [
     "serper",
     "apiserpent",
     "tinyfish",
+    "nimble",
 ]
 
 ALLOWED_FILES_IN_LLMS_FOLDER = [
diff --git a/tests/search_tests/test_nimble_search.py b/tests/search_tests/test_nimble_search.py
new file mode 100644
index 00000000000..c83b7236a09
--- /dev/null
+++ b/tests/search_tests/test_nimble_search.py
@@ -0,0 +1,155 @@
+"""
+Tests for Nimble Search API integration.
+"""
+
+import json
+import os
+import sys
+from unittest.mock import AsyncMock, Mock, patch
+
+import pytest
+
+sys.path.insert(0, os.path.abspath("../.."))
+
+import litellm
+from tests.search_tests.base_search_unit_tests import BaseSearchTest
+
+MOCK_NIMBLE_RESPONSE = {
+    "request_id": "0f8b3a1c-1d2e-4f5a-9b0c-6d7e8f9a0b1c",
+    "total_results": 2,
+    "results": [
+        {
+            "title": "Nimble Web API",
+            "description": "Short SERP description",
+            "url": "https://nimbleway.com/",
+            "content": "Full markdown content for the first result",
+            "metadata": {"position": 1, "entity_type": "organic", "country": "US", "locale": "en"},
+            "additional_data": {"publish_date": "2026-07-15"},
+        },
+        {
+            "title": "Nimble Docs",
+            "description": "Only a description here",
+            "url": "https://docs.nimbleway.com/",
+            "content": "",
+            "metadata": {"position": 2, "entity_type": "organic"},
+            "additional_data": None,
+        },
+    ],
+    "serp_data": None,
+}
+
+
+def _mock_response():
+    response = Mock()
+    response.status_code = 200
+    response.headers = {}
+    response.content = json.dumps(MOCK_NIMBLE_RESPONSE).encode()
+    return response
+
+
+@pytest.mark.skip(reason="Local only tested search providers")
+class TestNimbleSearch(BaseSearchTest):
+    """
+    E2E tests for Nimble Search functionality that make real API calls.
+    Inherits from BaseSearchTest to run standard search tests.
+    """
+
+    def get_search_provider(self) -> str:
+        return "nimble"
+
+
+class TestNimbleSearchTransformation:
+    """
+    Full-stack tests through `litellm.search` / `litellm.asearch` with the HTTP layer mocked.
+    Transformation details are unit-tested in tests/test_litellm/llms/nimble/search/.
+    """
+
+    @pytest.fixture(autouse=True)
+    def _server_key(self, monkeypatch: pytest.MonkeyPatch):
+        monkeypatch.setenv("NIMBLE_API_KEY", "test-api-key")
+        monkeypatch.delenv("NIMBLE_API_BASE", raising=False)
+
+    def test_nimble_search_request_and_response(self):
+        with patch(
+            "litellm.llms.custom_httpx.http_handler.HTTPHandler.post",
+            return_value=_mock_response(),
+        ) as mock_post:
+            response = litellm.search(
+                query="nimble web scraping",
+                search_provider="nimble",
+                max_results=2,
+                country="us",
+                search_domain_filter=["nimbleway.com", "-spam.example"],
+            )
+
+        assert mock_post.called
+        call_kwargs = mock_post.call_args.kwargs
+        assert call_kwargs["url"] == "https://sdk.nimbleway.com/v2/search"
+        assert call_kwargs["headers"]["Authorization"] == "Bearer test-api-key"
+        assert call_kwargs["headers"]["X-Client-Source"] == "litellm"
+
+        request_body = call_kwargs["json"]
+        assert request_body["query"] == "nimble web scraping"
+        assert request_body["max_results"] == 2
+        assert request_body["country"] == "US"
+        assert request_body["include_domains"] == ("nimbleway.com",)
+        assert request_body["exclude_domains"] == ("spam.example",)
+
+        assert response.object == "search"
+        assert len(response.results) == 2
+        assert response.results[0].title == "Nimble Web API"
+        assert response.results[0].url == "https://nimbleway.com/"
+        assert response.results[0].snippet == "Full markdown content for the first result"
+        assert response.results[0].date == "2026-07-15"
+        # Second result has no `content`, so the SERP description is the snippet.
+        assert response.results[1].snippet == "Only a description here"
+        assert response.results[1].date is None
+
+    def test_provider_specific_params_survive_to_the_wire(self):
+        """Nimble-native params must not be eaten by `filter_out_litellm_params`."""
+        with patch(
+            "litellm.llms.custom_httpx.http_handler.HTTPHandler.post",
+            return_value=_mock_response(),
+        ) as mock_post:
+            litellm.search(
+                query="test query",
+                search_provider="nimble",
+                focus="news",
+                search_depth="deep",
+                time_range="week",
+                locale="fr",
+                output_format="plain_text",
+                max_subagents=5,
+            )
+
+        request_body = mock_post.call_args.kwargs["json"]
+        assert request_body["focus"] == "news"
+        assert request_body["search_depth"] == "deep"
+        assert request_body["time_range"] == "week"
+        assert request_body["locale"] == "fr"
+        assert request_body["output_format"] == "plain_text"
+        assert request_body["max_subagents"] == 5
+
+    @pytest.mark.asyncio
+    async def test_nimble_asearch(self):
+        with patch(
+            "litellm.llms.custom_httpx.http_handler.AsyncHTTPHandler.post",
+            new=AsyncMock(return_value=_mock_response()),
+        ) as mock_post:
+            response = await litellm.asearch(
+                query="latest ai developments",
+                search_provider="nimble",
+                focus="news",
+            )
+
+        assert mock_post.call_args.kwargs["json"]["focus"] == "news"
+        assert len(response.results) == 2
+
+    def test_nimble_search_tracks_cost(self):
+        with patch(
+            "litellm.llms.custom_httpx.http_handler.HTTPHandler.post",
+            return_value=_mock_response(),
+        ):
+            response = litellm.search(query="pricing check", search_provider="nimble")
+
+        assert response._hidden_params["response_cost"] == pytest.approx(0.005)
diff --git a/tests/test_litellm/integrations/test_shadow_eval_logger.py b/tests/test_litellm/integrations/test_shadow_eval_logger.py
index e1c56db21af..3a69340109d 100644
--- a/tests/test_litellm/integrations/test_shadow_eval_logger.py
+++ b/tests/test_litellm/integrations/test_shadow_eval_logger.py
@@ -6,6 +6,7 @@ from datetime import datetime, timedelta, timezone
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
+from pydantic import ValidationError
 
 from litellm.caching.in_memory_cache import InMemoryCache
 from litellm.constants import INTERNAL_CALL_ORIGIN_METADATA_KEY
@@ -19,7 +20,7 @@ from litellm.integrations.shadow_eval_logger import (
     _sample_hits,
     _unmask_preference,
 )
-from litellm.types.utils import SHADOW_EVAL_JUDGE_CALL_ORIGIN, SHADOW_EVAL_ROUTER_CALL_ORIGIN
+from litellm.types.utils import SHADOW_EVAL_JUDGE_CALL_ORIGIN, SHADOW_EVAL_ROUTER_CALL_ORIGIN, ModelResponse
 
 
 def _job(**overrides) -> ActiveShadowEvalJob:
@@ -51,6 +52,8 @@ def _job_record(job: ActiveShadowEvalJob, api_key_id="key-hash") -> MagicMock:
         id=job.id,
         api_key_id=api_key_id,
         router_name=job.router_name,
+        direction=job.direction,
+        baseline_model=job.baseline_model,
         shadow_percentage=job.shadow_percentage,
         judge_model=job.judge_model,
         max_turns=job.max_turns,
@@ -61,40 +64,55 @@ def _job_record(job: ActiveShadowEvalJob, api_key_id="key-hash") -> MagicMock:
 
 
 def _router(shadow_text="shadow answer", judge_json='{"preference": "A", "confidence": 0.9, "reasoning": "x"}'):
-    """One mock router serving the shadow call first, the judge call second. The shadow
-    call's metadata receives the routing decision write-back, like the real router."""
+    """One mock router serving the shadow call first, the judge call second, told apart by
+    the internal-origin stamp rather than the model, since a reverse job's shadow arm names
+    a plain model. Only the auto-router writes a routing decision back, and only a plain
+    model reports the model it served on the response, which is how each direction learns
+    which model answered."""
     router = MagicMock()
     router.model_group_alias = {}
     router.get_model_list = MagicMock(return_value=[{"litellm_params": {"model": "openai/gpt-4o-mini"}}])
 
     async def acompletion(**kwargs):
+        if kwargs["metadata"].get(INTERNAL_CALL_ORIGIN_METADATA_KEY) != SHADOW_EVAL_ROUTER_CALL_ORIGIN:
+            return {"choices": [{"message": {"content": judge_json}}]}
         if kwargs["model"] == "my-router":
             kwargs["metadata"]["routing_decision"] = {"tier_label": "SIMPLE", "routed_model": "cheap-model"}
             return {"choices": [{"message": {"content": shadow_text}}], "usage": {"completion_tokens": 5}}
-        return {"choices": [{"message": {"content": judge_json}}]}
+        return ModelResponse(
+            model=kwargs["model"],
+            choices=[{"index": 0, "finish_reason": "stop", "message": {"role": "assistant", "content": shadow_text}}],
+        )
 
     router.acompletion = MagicMock(side_effect=acompletion)
     return router
 
 
-def _logger(router=None, prisma=None, job=None) -> ShadowEvalLogger:
+def _logger(router=None, prisma=None, jobs=()) -> ShadowEvalLogger:
     cache = InMemoryCache(max_size_in_memory=4, default_ttl=60)
     logger = ShadowEvalLogger(
         router_provider=lambda: router,
         prisma_provider=lambda: prisma,
         jobs_cache=cache,
     )
-    if job is not None:
-        cache.set_cache("shadow_eval:active_jobs", {"key-hash": job})
+    if jobs:
+        cache.set_cache("shadow_eval:active_jobs", {"key-hash": tuple(jobs)})
     return logger
 
 
-def _success_kwargs(request_id="req-1", api_key_hash="key-hash", request_metadata=None, call_type="acompletion"):
+def _routed_by(router_name="my-router", tier="COMPLEX"):
+    """Metadata as a pre-routing strategy leaves it on the request it served."""
+    return {"routing_decision": {"router_model_name": router_name, "tier_label": tier, "routed_model": "router-pick"}}
+
+
+def _success_kwargs(
+    request_id="req-1", api_key_hash="key-hash", request_metadata=None, call_type="acompletion", model="claude-opus"
+):
     return {
         "standard_logging_object": {
             "id": request_id,
             "call_type": call_type,
-            "model": "claude-opus",
+            "model": model,
             "metadata": {"user_api_key_hash": api_key_hash},
             "model_parameters": {"temperature": 0.5, "stream": True},
         },
@@ -164,7 +182,7 @@ class TestSuccessHookSkipChain:
         monkeypatch.setattr(litellm_module, "completion_cost", lambda completion_response: 0.005)
         prisma = _prisma()
         router = _router()
-        logger = _logger(router=router, prisma=prisma, job=_job())
+        logger = _logger(router=router, prisma=prisma, jobs=(_job(),))
 
         await logger.async_log_success_event(_success_kwargs(), RESPONSE, None, None)
         await _drain(logger)
@@ -209,7 +227,7 @@ class TestSuccessHookSkipChain:
     async def test_skip_paths_store_nothing(self, kwargs_mutation, job_mutation):
         starts = job_mutation.pop("_starts", 0)
         prisma = _prisma()
-        logger = _logger(router=_router(), prisma=prisma, job=_job(**job_mutation))
+        logger = _logger(router=_router(), prisma=prisma, jobs=(_job(**job_mutation),))
         logger._job_starts = {"job-1": starts}
 
         await logger.async_log_success_event(_success_kwargs(**kwargs_mutation), RESPONSE, None, None)
@@ -222,7 +240,7 @@ class TestSuccessHookSkipChain:
         """A finished pipeline frees its concurrency slot but not its slice of the turn
         budget; the budget only reopens when a cache refill absorbs the written rows."""
         prisma = _prisma()
-        logger = _logger(router=_router(), prisma=prisma, job=_job(attempts=199, max_turns=200))
+        logger = _logger(router=_router(), prisma=prisma, jobs=(_job(attempts=199, max_turns=200),))
 
         await logger.async_log_success_event(_success_kwargs(request_id="req-1"), RESPONSE, None, None)
         await _drain(logger)
@@ -237,7 +255,7 @@ class TestSuccessHookSkipChain:
         identity to the shadow and judge calls."""
         prisma = _prisma()
         router = _router()
-        logger = _logger(router=router, prisma=prisma, job=_job())
+        logger = _logger(router=router, prisma=prisma, jobs=(_job(),))
 
         hook_kwargs = _success_kwargs()
         hook_kwargs["litellm_params"] = {
@@ -256,7 +274,7 @@ class TestSuccessHookSkipChain:
         predicate, so every redaction source counts."""
         prisma = _prisma()
         router = _router()
-        logger = _logger(router=router, prisma=prisma, job=_job())
+        logger = _logger(router=router, prisma=prisma, jobs=(_job(),))
 
         hook_kwargs = _success_kwargs()
         hook_kwargs["standard_callback_dynamic_params"] = {"turn_off_message_logging": True}
@@ -268,7 +286,7 @@ class TestSuccessHookSkipChain:
 
     async def test_inflight_cap_sheds_instead_of_queueing(self):
         prisma = _prisma()
-        logger = _logger(router=_router(), prisma=prisma, job=_job())
+        logger = _logger(router=_router(), prisma=prisma, jobs=(_job(),))
         logger._inflight_shadow_tasks = _MAX_CONCURRENT_SHADOW_TASKS
 
         await logger.async_log_success_event(_success_kwargs(), RESPONSE, None, None)
@@ -291,8 +309,8 @@ class TestActiveJobsCache:
         first = await logger._active_jobs()
         second = await logger._active_jobs()
 
-        assert first["key-hash"].id == "job-1"
-        assert second["key-hash"].attempts == 7
+        assert [job.id for job in first["key-hash"]] == ["job-1"]
+        assert second["key-hash"][0].attempts == 7
         assert prisma.db.litellm_shadowevaljob.find_many.await_count == 1
         where = prisma.db.litellm_shadowevaljob.find_many.call_args.kwargs["where"]
         assert where["stopped_at"] is None
@@ -353,6 +371,7 @@ class TestShadowPipeline:
             messages=({"role": "user", "content": "hi"},),
             response_obj=RESPONSE,
             real_model="claude-opus",
+            control_tier=None,
             model_parameters={},
             parent_metadata={},
         )
@@ -381,6 +400,7 @@ class TestShadowPipeline:
             messages=({"role": "user", "content": "hi"},),
             response_obj=RESPONSE,
             real_model="claude-opus",
+            control_tier=None,
             model_parameters={},
             parent_metadata={"user_api_key_auth": UserAPIKeyAuth(api_key="sk-abc", max_budget=10.0)},
         )
@@ -411,6 +431,7 @@ class TestShadowPipeline:
             messages=({"role": "user", "content": "hi"},),
             response_obj=RESPONSE,
             real_model="claude-opus",
+            control_tier=None,
             model_parameters={},
             parent_metadata={},
         )
@@ -438,6 +459,7 @@ class TestShadowPipeline:
             messages=({"role": "user", "content": "hi"},),
             response_obj=RESPONSE,
             real_model="claude-opus",
+            control_tier=None,
             model_parameters={"stream": True, "temperature": 0.2, "metadata": {"x": 1}},
             parent_metadata=parent_metadata,
         )
@@ -458,6 +480,164 @@ class TestShadowPipeline:
         assert judge_call["max_tokens"] == JUDGE_MAX_OUTPUT_TOKENS
 
 
+def _reverse_job(**overrides) -> ActiveShadowEvalJob:
+    return _job(**{"direction": "reverse", "baseline_model": "baseline-model", **overrides})
+
+
+class TestJobValidation:
+    @pytest.mark.parametrize(
+        "overrides",
+        [
+            {"direction": "reverse"},
+            {"baseline_model": "baseline-model"},
+            {"direction": "sideways", "baseline_model": "baseline-model"},
+        ],
+        ids=["reverse-without-baseline", "forward-with-baseline", "unknown-direction"],
+    )
+    def test_unsamplable_shapes_are_rejected(self, overrides):
+        with pytest.raises(ValidationError):
+            _job(**overrides)
+
+    def test_shadow_target_follows_direction(self):
+        assert _job().shadow_target == "my-router"
+        assert _reverse_job().shadow_target == "baseline-model"
+
+
+@pytest.mark.asyncio
+class TestDirection:
+    @pytest.mark.parametrize(
+        "job,routed_by,sampled",
+        [
+            (_job(), None, True),
+            (_job(), "my-router", False),
+            (_job(), "other-router", True),
+            (_reverse_job(), "my-router", True),
+            (_reverse_job(), None, False),
+            (_reverse_job(), "other-router", False),
+        ],
+        ids=[
+            "forward-samples-unrouted",
+            "forward-skips-its-own-router",
+            "forward-samples-another-router",
+            "reverse-samples-its-own-router",
+            "reverse-skips-unrouted",
+            "reverse-skips-another-router",
+        ],
+    )
+    async def test_direction_decides_which_traffic_is_sampled(self, job, routed_by, sampled):
+        """The two directions partition the key's traffic: whatever one samples, the other
+        skips, so a key running both never judges the same turn twice for the same reason."""
+        prisma = _prisma()
+        logger = _logger(router=_router(), prisma=prisma, jobs=(job,))
+
+        await logger.async_log_success_event(
+            _success_kwargs(request_metadata=_routed_by(routed_by) if routed_by else {}), RESPONSE, None, None
+        )
+        await _drain(logger)
+
+        assert prisma.db.litellm_shadowevalattempt.create.await_count == int(sampled)
+
+    async def test_reverse_duplicates_against_the_baseline_model(self):
+        prisma = _prisma()
+        router = _router()
+        logger = _logger(router=router, prisma=prisma, jobs=(_reverse_job(),))
+
+        await logger.async_log_success_event(
+            _success_kwargs(request_metadata=_routed_by()), RESPONSE, None, None
+        )
+        await _drain(logger)
+
+        assert router.acompletion.call_args_list[0].kwargs["model"] == "baseline-model"
+
+    async def test_reverse_row_orients_arms_and_reads_tier_off_the_served_request(self):
+        """real is what the caller received, so in reverse it is the router's own pick and
+        the tier that produced it; only the shadow arm moves to the baseline."""
+        prisma = _prisma()
+        logger = _logger(router=_router(), prisma=prisma, jobs=(_reverse_job(),))
+
+        await logger.async_log_success_event(
+            _success_kwargs(request_metadata=_routed_by(tier="COMPLEX"), model="router-pick"), RESPONSE, None, None
+        )
+        await _drain(logger)
+
+        row = prisma.db.litellm_shadowevalattempt.create.call_args.kwargs["data"]
+        assert row["real_model"] == "router-pick"
+        assert row["shadow_model"] == "baseline-model"
+        assert row["tier"] == "COMPLEX"
+
+    async def test_forward_row_still_reads_tier_off_the_shadow_call(self):
+        """A forward job's tier describes the arm being evaluated, which is the shadow one,
+        so a routing decision on the incumbent request must not leak into it."""
+        prisma = _prisma()
+        logger = _logger(router=_router(), prisma=prisma, jobs=(_job(),))
+
+        await logger.async_log_success_event(
+            _success_kwargs(request_metadata=_routed_by("other-router", tier="CONTROL_TIER")), RESPONSE, None, None
+        )
+        await _drain(logger)
+
+        row = prisma.db.litellm_shadowevalattempt.create.call_args.kwargs["data"]
+        assert row["tier"] == "SIMPLE"
+        assert row["shadow_model"] == "cheap-model"
+
+    async def test_a_key_running_both_directions_dispatches_both(self):
+        """One request can qualify for a forward job on a router that did not serve it and a
+        reverse job on the router that did. The two are separately budgeted experiments, so
+        both fire rather than one silently losing the turn."""
+        prisma = _prisma()
+        logger = _logger(
+            router=_router(),
+            prisma=prisma,
+            jobs=(_job(id="forward-job", router_name="other-router"), _reverse_job(id="reverse-job")),
+        )
+
+        await logger.async_log_success_event(
+            _success_kwargs(request_metadata=_routed_by()), RESPONSE, None, None
+        )
+        await _drain(logger)
+
+        rows = [call.kwargs["data"] for call in prisma.db.litellm_shadowevalattempt.create.call_args_list]
+        assert sorted(row["job_id"] for row in rows) == ["forward-job", "reverse-job"]
+        assert logger._job_starts == {"forward-job": 1, "reverse-job": 1}
+
+
+@pytest.mark.asyncio
+class TestActiveJobsFailClosed:
+    async def test_a_row_the_sampler_cannot_read_is_dropped_not_guessed(self):
+        """A reverse row with no baseline model has no second arm to call, so it is skipped
+        rather than silently dispatched at the router it is supposed to be judging."""
+        broken = _job_record(_job(id="job-broken"))
+        broken.direction = "reverse"
+        broken.baseline_model = None
+        prisma = _prisma(jobs=[broken, _job_record(_job(id="job-ok"))], attempt_counts=[("job-ok", 1)])
+        logger = ShadowEvalLogger(
+            router_provider=lambda: None,
+            prisma_provider=lambda: prisma,
+            jobs_cache=InMemoryCache(max_size_in_memory=4, default_ttl=60),
+        )
+
+        assert [job.id for job in (await logger._active_jobs())["key-hash"]] == ["job-ok"]
+
+    async def test_both_of_a_key_s_jobs_survive_the_lookup(self):
+        records = [
+            _job_record(_job(id="job-forward")),
+            _job_record(_reverse_job(id="job-reverse")),
+            _job_record(_job(id="job-other"), api_key_id="other-key"),
+        ]
+        prisma = _prisma(jobs=records, attempt_counts=[("job-reverse", 3)])
+        logger = ShadowEvalLogger(
+            router_provider=lambda: None,
+            prisma_provider=lambda: prisma,
+            jobs_cache=InMemoryCache(max_size_in_memory=4, default_ttl=60),
+        )
+
+        jobs = await logger._active_jobs()
+
+        assert sorted(job.id for job in jobs["key-hash"]) == ["job-forward", "job-reverse"]
+        assert [job.id for job in jobs["other-key"]] == ["job-other"]
+        assert {job.id: job.attempts for job in jobs["key-hash"]}["job-reverse"] == 3
+
+
 def _failing_router():
     router = MagicMock()
     router.model_group_alias = {}
diff --git a/tests/test_litellm/llms/base_llm/search/test_base_search_transformation.py b/tests/test_litellm/llms/base_llm/search/test_base_search_transformation.py
index a1353d57038..b93ffdb0b44 100644
--- a/tests/test_litellm/llms/base_llm/search/test_base_search_transformation.py
+++ b/tests/test_litellm/llms/base_llm/search/test_base_search_transformation.py
@@ -27,6 +27,7 @@ from litellm.llms.fastcrw.search.transformation import FastCRWSearchConfig
 from litellm.llms.firecrawl.search.transformation import FirecrawlSearchConfig
 from litellm.llms.google_pse.search.transformation import GooglePSESearchConfig
 from litellm.llms.linkup.search.transformation import LinkupSearchConfig
+from litellm.llms.nimble.search.transformation import NimbleSearchConfig
 from litellm.llms.parallel_ai.search.transformation import ParallelAISearchConfig
 from litellm.llms.perplexity.search.transformation import PerplexitySearchConfig
 from litellm.llms.searchapi.search.transformation import SearchAPIConfig
@@ -57,6 +58,7 @@ _BASE_ENV_VARS = (
     "DATAFORSEO_API_BASE",
     "TINYFISH_API_BASE",
     "CRW_API_BASE",
+    "NIMBLE_API_BASE",
 )
 
 
@@ -96,6 +98,7 @@ PROVIDERS: Tuple[ProviderSpec, ...] = (
     ),
     (TinyfishSearchConfig, {"TINYFISH_API_KEY": "srv"}, "caller-key", {}),
     (FastCRWSearchConfig, {"CRW_API_KEY": "srv"}, "caller-key", {}),
+    (NimbleSearchConfig, {"NIMBLE_API_KEY": "srv"}, "caller-key", {}),
 )
 
 _IDS = tuple(spec[0].__name__ for spec in PROVIDERS)
diff --git a/tests/test_litellm/llms/nimble/search/test_nimble_search_transformation.py b/tests/test_litellm/llms/nimble/search/test_nimble_search_transformation.py
new file mode 100644
index 00000000000..d6292c9cf3e
--- /dev/null
+++ b/tests/test_litellm/llms/nimble/search/test_nimble_search_transformation.py
@@ -0,0 +1,251 @@
+import json
+from unittest.mock import Mock
+
+import pytest
+
+from litellm.llms.nimble.search.transformation import NimbleSearchConfig
+
+
+def _config() -> NimbleSearchConfig:
+    return NimbleSearchConfig()
+
+
+def _resp(payload, status_code: int = 200):
+    r = Mock()
+    r.status_code = status_code
+    r.headers = {}
+    r.content = (payload if isinstance(payload, str) else json.dumps(payload)).encode()
+    return r
+
+
+def _result(**overrides):
+    base = {
+        "title": "Test Title",
+        "description": "Test description",
+        "url": "https://example.com",
+        "content": "Test content",
+        "metadata": {"position": 1, "entity_type": "organic"},
+        "additional_data": None,
+    }
+    return {**base, **overrides}
+
+
+def test_ui_friendly_name():
+    assert _config().ui_friendly_name() == "Nimble"
+
+
+def test_validate_environment_with_explicit_key():
+    headers = _config().validate_environment({}, api_key="explicit-key")
+    assert headers["Authorization"] == "Bearer explicit-key"
+    assert headers["Content-Type"] == "application/json"
+    assert headers["X-Client-Source"] == "litellm"
+
+
+def test_validate_environment_reads_env_key(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setenv("NIMBLE_API_KEY", "env-key")
+    assert _config().validate_environment({})["Authorization"] == "Bearer env-key"
+
+
+def test_validate_environment_missing_key_raises(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.delenv("NIMBLE_API_KEY", raising=False)
+    with pytest.raises(ValueError, match="NIMBLE_API_KEY"):
+        _config().validate_environment({})
+
+
+def test_validate_environment_does_not_mutate_and_is_idempotent():
+    """The http handler re-runs validate_environment after search/main.py already did."""
+    config = _config()
+    caller_headers = {"X-Custom": "keep-me"}
+
+    once = config.validate_environment(caller_headers, api_key="k")
+    twice = config.validate_environment(once, api_key="k")
+
+    assert caller_headers == {"X-Custom": "keep-me"}
+    assert once == twice
+    assert once["X-Custom"] == "keep-me"
+
+
+def test_get_complete_url_default_base(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.delenv("NIMBLE_API_BASE", raising=False)
+    assert _config().get_complete_url(None, {}) == "https://sdk.nimbleway.com/v2/search"
+
+
+def test_get_complete_url_reads_env_base(monkeypatch: pytest.MonkeyPatch):
+    monkeypatch.setenv("NIMBLE_API_BASE", "https://env-base.local/v2")
+    assert _config().get_complete_url(None, {}) == "https://env-base.local/v2/search"
+
+
+@pytest.mark.parametrize(
+    "api_base",
+    [
+        "https://self-hosted.local/v2",
+        "https://self-hosted.local/v2/",
+        "https://self-hosted.local/v2/search",
+        "https://self-hosted.local/v2/search/",
+    ],
+)
+def test_get_complete_url_appends_search_exactly_once(api_base: str):
+    assert _config().get_complete_url(api_base, {}) == "https://self-hosted.local/v2/search"
+
+
+def test_transform_search_request_joins_list_query():
+    assert _config().transform_search_request(["foo", "bar"], {})["query"] == "foo bar"
+
+
+def test_transform_search_request_max_results_is_not_clamped():
+    """Nimble validates 1-100 itself; a clearer error beats silently rewriting the request."""
+    assert _config().transform_search_request("q", {"max_results": 500})["max_results"] == 500
+
+
+def test_transform_search_request_uppercases_country():
+    assert _config().transform_search_request("q", {"country": "us"})["country"] == "US"
+
+
+def test_transform_search_request_drops_max_tokens_per_page():
+    assert "max_tokens_per_page" not in _config().transform_search_request("q", {"max_tokens_per_page": 1024})
+
+
+def test_transform_search_request_splits_domain_filter():
+    data = _config().transform_search_request("q", {"search_domain_filter": ["arxiv.org", "-spam.com", "nature.com"]})
+    assert data["include_domains"] == ("arxiv.org", "nature.com")
+    assert data["exclude_domains"] == ("spam.com",)
+
+
+def test_transform_search_request_omits_empty_domain_lists():
+    data = _config().transform_search_request("q", {"search_domain_filter": ["arxiv.org"]})
+    assert data["include_domains"] == ("arxiv.org",)
+    assert "exclude_domains" not in data
+
+
+def test_transform_search_request_ignores_non_list_domain_filter():
+    assert "include_domains" not in _config().transform_search_request("q", {"search_domain_filter": "arxiv.org"})
+
+
+@pytest.mark.parametrize("native_key", ["include_domains", "exclude_domains"])
+def test_transform_search_request_native_domains_win(native_key: str):
+    """An explicit provider-native value must not be silently clobbered by the unified param."""
+    data = _config().transform_search_request(
+        "q",
+        {"search_domain_filter": ["derived.com", "-derived-ex.com"], native_key: ["native.com"]},
+    )
+    assert data[native_key] == ["native.com"]
+
+
+def test_transform_search_response_prefers_content():
+    resp = _config().transform_search_response(_resp({"results": [_result()]}), logging_obj=Mock())
+    assert resp.results[0].snippet == "Test content"
+
+
+def test_transform_search_response_falls_back_to_description():
+    resp = _config().transform_search_response(_resp({"results": [_result(content="")]}), logging_obj=Mock())
+    assert resp.results[0].snippet == "Test description"
+
+
+def test_transform_search_response_reads_publish_date():
+    resp = _config().transform_search_response(
+        _resp({"results": [_result(additional_data={"publish_date": "2026-08-01"})]}),
+        logging_obj=Mock(),
+    )
+    assert resp.results[0].date == "2026-08-01"
+
+
+@pytest.mark.parametrize("additional_data", [{}, "not-a-dict"])
+def test_transform_search_response_date_is_none_without_usable_publish_date(additional_data):
+    resp = _config().transform_search_response(
+        _resp({"results": [_result(additional_data=additional_data)]}), logging_obj=Mock()
+    )
+    assert resp.results[0].date is None
+
+
+def test_transform_search_response_keeps_additional_data():
+    """News results often carry only a relative `publish_date_raw`, which is not a date;
+    it must still reach the caller rather than being dropped on the floor."""
+    resp = _config().transform_search_response(
+        _resp({"results": [_result(additional_data={"publish_date_raw": "1 day ago"})]}),
+        logging_obj=Mock(),
+    )
+    assert resp.results[0].date is None
+    assert resp.results[0].additional_data == {"publish_date_raw": "1 day ago"}
+
+
+def test_transform_search_response_omits_additional_data_when_absent():
+    resp = _config().transform_search_response(_resp({"results": [_result()]}), logging_obj=Mock())
+    assert not hasattr(resp.results[0], "additional_data")
+
+
+def test_transform_search_response_preserves_order():
+    resp = _config().transform_search_response(
+        _resp({"results": [_result(title=t) for t in ("first", "second", "third")]}),
+        logging_obj=Mock(),
+    )
+    assert [r.title for r in resp.results] == ["first", "second", "third"]
+
+
+def test_transform_search_response_degraded_result_does_not_fail_the_call():
+    resp = _config().transform_search_response(
+        _resp({"results": [{"url": "https://example.com"}, _result()]}), logging_obj=Mock()
+    )
+    assert len(resp.results) == 2
+    assert resp.results[0].title == ""
+    assert resp.results[0].snippet == ""
+    assert resp.results[1].title == "Test Title"
+
+
+def test_transform_search_response_zero_hits():
+    """A search with no hits really does come back as `"results": []`."""
+    payload = {"request_id": "abc", "total_results": 0, "results": []}
+    assert _config().transform_search_response(_resp(payload), logging_obj=Mock()).results == []
+
+
+@pytest.mark.parametrize(
+    "body",
+    [
+        "<html>502 Bad Gateway</html>",  # non-JSON body
+        '{"results": ["garbage"]}',  # right key, wrong element shape
+        '{"results": {"unexpected": "shape"}}',
+        '{"results": null}',  # must not degrade to a successful empty search
+        "{}",  # ditto for an absent key
+    ],
+)
+def test_transform_search_response_malformed_body_raises_instead_of_reporting_empty(body: str):
+    """A body LiteLLM cannot parse must not be reported as a successful zero-result search."""
+    with pytest.raises(Exception, match="Nimble Search"):
+        _config().transform_search_response(_resp(body, status_code=502), logging_obj=Mock())
+
+
+def test_get_error_class_attributes_the_provider():
+    error = _config().get_error_class(error_message="quota exceeded", status_code=429, headers={})
+    assert error.status_code == 429
+    assert "Nimble Search: quota exceeded" in str(error)
+    assert "docs.nimbleway.com" in str(error)
+
+
+def test_get_error_class_unwraps_nimble_detail_envelope():
+    """Verbatim body from a live 422; the raw JSON envelope should not reach the user."""
+    error = _config().get_error_class(
+        error_message='{"detail":"search_depth=\'fast\' is only supported with focus=\'general\'."}',
+        status_code=422,
+        headers={},
+    )
+    assert (
+        str(error) == "Nimble Search: search_depth='fast' is only supported with focus='general'. "
+        "See https://docs.nimbleway.com/api-reference/search/search for details."
+    )
+
+
+def test_get_error_class_unwraps_nimble_message_envelope():
+    """Verbatim body from a live collection failure, which uses a different envelope."""
+    error = _config().get_error_class(
+        error_message='{"success":"false","task_id":"4f74af04","message":"can\'t download the query response"}',
+        status_code=500,
+        headers={},
+    )
+    assert (
+        str(error) == "Nimble Search: can't download the query response. "
+        "See https://docs.nimbleway.com/api-reference/search/search for details."
+    )
+
+
+@pytest.mark.parametrize("body", ["<html>502 Bad Gateway</html>", '{"detail": null}'])
+def test_get_error_class_falls_back_to_the_raw_body(body: str):
+    assert f"Nimble Search: {body}." in str(_config().get_error_class(body, status_code=500, headers={}))
diff --git a/tests/test_litellm/proxy/_experimental/mcp_server/test_utils.py b/tests/test_litellm/proxy/_experimental/mcp_server/test_utils.py
index 00ed4e91efa..0252fb9843d 100644
--- a/tests/test_litellm/proxy/_experimental/mcp_server/test_utils.py
+++ b/tests/test_litellm/proxy/_experimental/mcp_server/test_utils.py
@@ -4,12 +4,32 @@ import pytest
 from fastapi import HTTPException
 
 from litellm.proxy._experimental.mcp_server.utils import (
+    _upstream_credential_headers,
     build_synthetic_mcp_request,
     logging_safe_mcp_headers,
     validate_and_normalize_mcp_server_payload,
     validate_tool_display_names,
 )
 from litellm.proxy._types import NewMCPServerRequest
+from litellm.types.mcp_server.mcp_server_manager import MCPServer
+
+
+def _server_forwarding(*header_names: str) -> MCPServer:
+    return MCPServer(
+        server_id="srv-1",
+        name="deepwiki",
+        transport="http",
+        url="https://mcp.example.com/mcp",
+        extra_headers=list(header_names),
+    )
+
+
+def _configured_servers(*servers: MCPServer):
+    return patch.dict(
+        "litellm.proxy._experimental.mcp_server.mcp_server_manager.global_mcp_server_manager.config_mcp_servers",
+        {server.server_id: server for server in servers},
+        clear=False,
+    )
 
 
 class TestValidateToolDisplayNames:
@@ -114,6 +134,70 @@ class TestLoggingSafeMcpHeaders:
 
         assert safe == {"x-nuid": "nuid-1"}
 
+    def test_strips_headers_a_server_forwards_upstream(self):
+        """mcp_servers.<name>.extra_headers names the headers the proxy relays upstream, so a
+        caller supplied value under one of them is an upstream credential no prefix rule can spot.
+        Config is written in canonical casing while the wire header arrives lowercased."""
+        with _configured_servers(_server_forwarding("X-GitHub-Token", "X-Tenant")):
+            safe = logging_safe_mcp_headers({"x-github-token": "ghp_secret", "x-tenant": "acct-1", "x-nuid": "nuid-1"})
+
+        assert safe == {"x-nuid": "nuid-1"}
+
+    def test_strips_caller_asserted_host(self):
+        """This mapping reaches the guardrail payload and the list_tools spend row, so a caller
+        must not be able to name the deployment there either."""
+        safe = logging_safe_mcp_headers({"host": "evil.attacker.example", "x-nuid": "nuid-1"})
+
+        assert safe == {"x-nuid": "nuid-1"}
+
+    def test_keeps_identity_header_a_server_also_forwards(self):
+        """get_user_from_headers resolves end user attribution off this same request, so a header
+        the deployment reads identity from stays even when a server forwards it upstream."""
+        with patch.dict(
+            "litellm.proxy.proxy_server.general_settings",
+            {"user_header_name": "x-user-email"},
+            clear=False,
+        ):
+            with _configured_servers(_server_forwarding("x-user-email", "x-github-token")):
+                safe = logging_safe_mcp_headers({"x-user-email": "alice@corp.example", "x-github-token": "ghp_secret"})
+
+        assert safe == {"x-user-email": "alice@corp.example"}
+
+    @pytest.mark.parametrize(
+        "configured",
+        [
+            [{"header_name": "X-User", "litellm_user_role": "customer"}],
+            {"header_name": "X-User", "litellm_user_role": "customer"},
+        ],
+        ids=["list-of-mappings", "bare-mapping"],
+    )
+    def test_keeps_identity_header_from_user_header_mappings(self, configured):
+        """get_internal_user_header_from_mapping and get_customer_user_header_from_mapping both
+        accept a bare mapping as well as a list, and config_settings.md documents the key as a
+        dict, so the exemption has to read both shapes."""
+        with patch.dict(
+            "litellm.proxy.proxy_server.general_settings",
+            {"user_header_mappings": configured},
+            clear=False,
+        ):
+            with _configured_servers(_server_forwarding("X-User", "X-GitHub-Token")):
+                safe = logging_safe_mcp_headers({"x-user": "alice", "x-github-token": "ghp_secret"})
+
+        assert safe == {"x-user": "alice"}
+
+    def test_keeps_authorization_classification_for_oauth_passthrough(self):
+        """clean_headers already strips authorization, and claiming it here would change which
+        header authenticated_with_header resolves to on a config that lists it by design."""
+        with _configured_servers(_server_forwarding("Authorization", "X-GitHub-Token")):
+            assert "authorization" not in _upstream_credential_headers(["authorization", "x-github-token"])
+            assert "x-github-token" in _upstream_credential_headers(["authorization", "x-github-token"])
+
+    def test_keeps_headers_when_no_server_forwards_them(self):
+        with _configured_servers(_server_forwarding("x-github-token")):
+            safe = logging_safe_mcp_headers({"x-other-token": "not-forwarded", "x-nuid": "nuid-1"})
+
+        assert safe == {"x-other-token": "not-forwarded", "x-nuid": "nuid-1"}
+
 
 class TestBuildSyntheticMcpRequest:
     def test_forwards_client_headers_without_upstream_credentials(self):
@@ -147,3 +231,41 @@ class TestBuildSyntheticMcpRequest:
 
         assert request.headers.get("x-nuid") == "nuid-1"
         assert "x-company-key" not in request.headers
+
+    def test_drops_caller_host_so_the_logged_url_is_not_client_steerable(self):
+        """add_litellm_data_to_request records str(request.url) as proxy_server_request.url, and
+        Request.url is built from the host header, so forwarding it hands the caller that value."""
+        request = build_synthetic_mcp_request(
+            path="/mcp/tools/call",
+            raw_headers={"host": "evil.attacker.example", "x-nuid": "nuid-1"},
+        )
+
+        assert "evil.attacker.example" not in str(request.url)
+        assert "host" not in request.headers
+        assert request.headers.get("x-nuid") == "nuid-1"
+
+    def test_drops_headers_a_server_forwards_upstream(self):
+        with _configured_servers(_server_forwarding("x-github-token")):
+            request = build_synthetic_mcp_request(
+                path="/mcp/tools/call",
+                raw_headers={"x-github-token": "ghp_secret", "x-nuid": "nuid-1"},
+            )
+
+        assert "x-github-token" not in request.headers
+        assert request.headers.get("x-nuid") == "nuid-1"
+
+    def test_keeps_identity_header_so_end_user_attribution_survives(self):
+        """add_litellm_data_to_request reads user_header_name off this request to fill
+        end_user_id, so forwarding that header upstream must not remove it here."""
+        with patch.dict(
+            "litellm.proxy.proxy_server.general_settings",
+            {"user_header_name": "x-user-email"},
+            clear=False,
+        ):
+            with _configured_servers(_server_forwarding("x-user-email")):
+                request = build_synthetic_mcp_request(
+                    path="/mcp/tools/call",
+                    raw_headers={"x-user-email": "alice@corp.example"},
+                )
+
+        assert request.headers.get("x-user-email") == "alice@corp.example"
diff --git a/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py b/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py
index 33372e7794a..3325893c5f6 100644
--- a/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py
+++ b/tests/test_litellm/proxy/db/db_transaction_queue/test_redis_update_buffer.py
@@ -270,6 +270,70 @@ async def test_get_all_transactions_from_redis_buffer_pipeline_no_redis():
     assert result == (None, None, None, None, None, None)
 
 
+@pytest.mark.asyncio
+async def test_restore_transactions_to_redis_pushes_only_provided(
+    redis_update_buffer, mock_redis_cache
+):
+    """
+    restore_transactions_to_redis re-pushes only the transaction sets it was
+    given, to their matching buffer keys, so uncommitted spend can be retried.
+    """
+    from litellm.constants import (
+        REDIS_DAILY_SPEND_UPDATE_BUFFER_KEY,
+        REDIS_UPDATE_BUFFER_KEY,
+    )
+
+    mock_redis_cache.async_rpush_pipeline = AsyncMock(return_value=[1, 1])
+
+    db_spend = {"key_list_transactions": {"key1": 1.0}}
+    daily_user = {"user_key1": {"spend": 1.0}}
+
+    await redis_update_buffer.restore_transactions_to_redis(
+        db_spend_update_transactions=db_spend,
+        daily_spend_update_transactions=daily_user,
+    )
+
+    mock_redis_cache.async_rpush_pipeline.assert_called_once()
+    rpush_list = mock_redis_cache.async_rpush_pipeline.call_args.kwargs["rpush_list"]
+    pushed_keys = {op["key"] for op in rpush_list}
+    assert pushed_keys == {
+        REDIS_UPDATE_BUFFER_KEY,
+        REDIS_DAILY_SPEND_UPDATE_BUFFER_KEY,
+    }
+    # Payloads round-trip through the same JSON encoding used on the store path
+    payloads = {op["key"]: json.loads(op["values"][0]) for op in rpush_list}
+    assert payloads[REDIS_UPDATE_BUFFER_KEY] == db_spend
+    assert payloads[REDIS_DAILY_SPEND_UPDATE_BUFFER_KEY] == daily_user
+
+
+@pytest.mark.asyncio
+async def test_restore_transactions_to_redis_noop_when_empty(
+    redis_update_buffer, mock_redis_cache
+):
+    """Nothing to restore -> no Redis call."""
+    mock_redis_cache.async_rpush_pipeline = AsyncMock()
+    await redis_update_buffer.restore_transactions_to_redis()
+    mock_redis_cache.async_rpush_pipeline.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_restore_transactions_to_redis_swallows_redis_error(
+    redis_update_buffer, mock_redis_cache
+):
+    """A Redis failure during restore must not propagate to the caller's finally block."""
+    from redis.exceptions import RedisError
+
+    mock_redis_cache.async_rpush_pipeline = AsyncMock(
+        side_effect=RedisError("redis down")
+    )
+
+    await redis_update_buffer.restore_transactions_to_redis(
+        db_spend_update_transactions={"key_list_transactions": {"key1": 1.0}},
+    )
+
+    mock_redis_cache.async_rpush_pipeline.assert_called_once()
+
+
 def test_validate_redis_transaction_buffer_raises_without_redis():
     """
     When use_redis_transaction_buffer=true but no Redis cache is configured,
diff --git a/tests/test_litellm/proxy/db/test_db_spend_update_writer.py b/tests/test_litellm/proxy/db/test_db_spend_update_writer.py
index ca7d5fcd273..6cf41497404 100644
--- a/tests/test_litellm/proxy/db/test_db_spend_update_writer.py
+++ b/tests/test_litellm/proxy/db/test_db_spend_update_writer.py
@@ -1425,6 +1425,52 @@ async def test_update_daily_spend_re_raises_exception_after_logging():
         )
 
 
+@pytest.mark.asyncio
+async def test_update_daily_spend_keeps_failed_transactions_for_retry():
+    """
+    A failed batch must stay in the caller's transaction dict, otherwise the
+    Redis re-queue in _commit_spend_updates_to_db_with_redis has nothing left to
+    push back and the spend is lost permanently.
+    """
+
+    def raise_outage():
+        raise ValueError("simulated database outage")
+
+    prisma_client = _RecordingPrisma(execute_raw=raise_outage)
+
+    daily_spend_transactions = {
+        "test_key": {
+            "user_id": "test-user",
+            "date": "2024-01-01",
+            "api_key": "test-api-key",
+            "model": "gpt-4",
+            "custom_llm_provider": "openai",
+            "prompt_tokens": 10,
+            "completion_tokens": 20,
+            "spend": 0.1,
+            "api_requests": 1,
+            "successful_requests": 1,
+            "failed_requests": 0,
+        }
+    }
+    expected = dict(daily_spend_transactions)
+
+    mock_proxy_logging = MagicMock()
+    mock_proxy_logging.failure_handler = AsyncMock()
+
+    with pytest.raises(ValueError, match="simulated database outage"):
+        await DBSpendUpdateWriter._update_daily_spend(
+            n_retry_times=0,
+            prisma_client=prisma_client,
+            proxy_logging_obj=mock_proxy_logging,
+            daily_spend_transactions=daily_spend_transactions,
+            entity_type="user",
+            entity_id_field="user_id",
+        )
+
+    assert daily_spend_transactions == expected
+
+
 @pytest.mark.asyncio
 async def test_commit_key_spend_updates_includes_last_active():
     """
@@ -1685,9 +1731,9 @@ async def test_commit_spend_updates_uses_pipeline():
 
     mock_redis_update_buffer = AsyncMock()
     mock_redis_update_buffer.store_in_memory_spend_updates_in_redis = AsyncMock()
-    # Return all-None tuple (no data to commit)
+    # Return all-None tuple (no data to commit); the pipeline yields 6 slots
     mock_redis_update_buffer.get_all_transactions_from_redis_buffer_pipeline = (
-        AsyncMock(return_value=(None, None, None, None, None, None, None))
+        AsyncMock(return_value=(None, None, None, None, None, None))
     )
     db_writer.redis_update_buffer = mock_redis_update_buffer
 
@@ -1718,6 +1764,225 @@ async def test_commit_spend_updates_uses_pipeline():
     mock_redis_update_buffer.get_all_daily_tag_spend_update_transactions_from_redis_buffer.assert_not_called()
 
 
+@pytest.mark.asyncio
+async def test_commit_with_redis_requeues_all_on_db_failure():
+    """
+    Regression for #33872: if the DB commit fails after the leader has already
+    popped transactions from Redis, the popped transactions must be re-queued to
+    Redis so a later tick can retry them, instead of being silently lost.
+    """
+    db_writer = DBSpendUpdateWriter()
+
+    db_spend = {
+        "user_list_transactions": {"user1": 1.5},
+        "end_user_list_transactions": {},
+        "key_list_transactions": {"key1": 1.5},
+        "team_list_transactions": {},
+        "team_member_list_transactions": {},
+        "org_list_transactions": {},
+        "tag_list_transactions": {},
+        "agent_list_transactions": {},
+    }
+    daily_user = {"user_key1": {"spend": 1.5, "api_requests": 1}}
+
+    mock_redis_update_buffer = AsyncMock()
+    mock_redis_update_buffer.get_all_transactions_from_redis_buffer_pipeline = AsyncMock(
+        return_value=(db_spend, daily_user, None, None, None, None)
+    )
+    mock_redis_update_buffer.restore_transactions_to_redis = AsyncMock()
+    db_writer.redis_update_buffer = mock_redis_update_buffer
+
+    mock_pod_lock_manager = AsyncMock()
+    mock_pod_lock_manager.acquire_lock = AsyncMock(return_value=True)
+    mock_pod_lock_manager.release_lock = AsyncMock()
+    db_writer.pod_lock_manager = mock_pod_lock_manager
+
+    # Every DB write raises -> simulates a full database outage
+    db_writer._commit_spend_updates_to_db = AsyncMock(side_effect=Exception("db down"))
+
+    with patch.object(
+        DBSpendUpdateWriter,
+        "update_daily_user_spend",
+        new=AsyncMock(side_effect=Exception("db down")),
+    ):
+        await db_writer._commit_spend_updates_to_db_with_redis(
+            prisma_client=MagicMock(),
+            n_retry_times=0,
+            proxy_logging_obj=MagicMock(),
+        )
+
+    # Both failed categories must be re-queued to Redis, nothing lost
+    mock_redis_update_buffer.restore_transactions_to_redis.assert_awaited_once()
+    _, kwargs = mock_redis_update_buffer.restore_transactions_to_redis.call_args
+    assert kwargs["db_spend_update_transactions"] == db_spend
+    assert kwargs["daily_spend_update_transactions"] == daily_user
+    # The lock must still be released
+    mock_pod_lock_manager.release_lock.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_commit_with_redis_only_requeues_failed_category():
+    """
+    A partial DB failure must not re-queue categories that already committed,
+    otherwise their spend would be double-counted on the next tick.
+    """
+    db_writer = DBSpendUpdateWriter()
+
+    db_spend = {
+        "user_list_transactions": {"user1": 1.5},
+        "end_user_list_transactions": {},
+        "key_list_transactions": {},
+        "team_list_transactions": {},
+        "team_member_list_transactions": {},
+        "org_list_transactions": {},
+        "tag_list_transactions": {},
+        "agent_list_transactions": {},
+    }
+    daily_user = {"user_key1": {"spend": 1.5, "api_requests": 1}}
+
+    mock_redis_update_buffer = AsyncMock()
+    mock_redis_update_buffer.get_all_transactions_from_redis_buffer_pipeline = AsyncMock(
+        return_value=(db_spend, daily_user, None, None, None, None)
+    )
+    mock_redis_update_buffer.restore_transactions_to_redis = AsyncMock()
+    db_writer.redis_update_buffer = mock_redis_update_buffer
+
+    mock_pod_lock_manager = AsyncMock()
+    mock_pod_lock_manager.acquire_lock = AsyncMock(return_value=True)
+    mock_pod_lock_manager.release_lock = AsyncMock()
+    db_writer.pod_lock_manager = mock_pod_lock_manager
+
+    # db_spend commits fine; only the daily user commit fails
+    db_writer._commit_spend_updates_to_db = AsyncMock()
+
+    with patch.object(
+        DBSpendUpdateWriter,
+        "update_daily_user_spend",
+        new=AsyncMock(side_effect=Exception("db down")),
+    ):
+        await db_writer._commit_spend_updates_to_db_with_redis(
+            prisma_client=MagicMock(),
+            n_retry_times=0,
+            proxy_logging_obj=MagicMock(),
+        )
+
+    mock_redis_update_buffer.restore_transactions_to_redis.assert_awaited_once()
+    _, kwargs = mock_redis_update_buffer.restore_transactions_to_redis.call_args
+    # Only the failed daily category is requeued; the committed db_spend is not
+    assert kwargs == {"daily_spend_update_transactions": daily_user}
+
+
+@pytest.mark.asyncio
+async def test_commit_with_redis_no_requeue_on_success():
+    """When all commits succeed, nothing should be re-queued to Redis."""
+    db_writer = DBSpendUpdateWriter()
+
+    db_spend = {
+        "user_list_transactions": {"user1": 1.5},
+        "end_user_list_transactions": {},
+        "key_list_transactions": {},
+        "team_list_transactions": {},
+        "team_member_list_transactions": {},
+        "org_list_transactions": {},
+        "tag_list_transactions": {},
+        "agent_list_transactions": {},
+    }
+
+    mock_redis_update_buffer = AsyncMock()
+    mock_redis_update_buffer.get_all_transactions_from_redis_buffer_pipeline = AsyncMock(
+        return_value=(db_spend, None, None, None, None, None)
+    )
+    mock_redis_update_buffer.restore_transactions_to_redis = AsyncMock()
+    db_writer.redis_update_buffer = mock_redis_update_buffer
+
+    mock_pod_lock_manager = AsyncMock()
+    mock_pod_lock_manager.acquire_lock = AsyncMock(return_value=True)
+    mock_pod_lock_manager.release_lock = AsyncMock()
+    db_writer.pod_lock_manager = mock_pod_lock_manager
+
+    db_writer._commit_spend_updates_to_db = AsyncMock()
+
+    await db_writer._commit_spend_updates_to_db_with_redis(
+        prisma_client=MagicMock(),
+        n_retry_times=0,
+        proxy_logging_obj=MagicMock(),
+    )
+
+    mock_redis_update_buffer.restore_transactions_to_redis.assert_not_awaited()
+
+
+@pytest.mark.asyncio
+async def test_commit_daily_tag_spend_requeues_on_db_failure():
+    """A failed daily tag commit must re-queue the popped tag transactions and release the lock."""
+    db_writer = DBSpendUpdateWriter()
+
+    daily_tag = {"tag_key1": {"spend": 1.5, "api_requests": 1}}
+
+    mock_redis_update_buffer = AsyncMock()
+    mock_redis_update_buffer.store_in_memory_daily_tag_spend_updates_in_redis = AsyncMock()
+    mock_redis_update_buffer.get_all_daily_tag_spend_update_transactions_from_redis_buffer = AsyncMock(
+        return_value=daily_tag
+    )
+    mock_redis_update_buffer.restore_transactions_to_redis = AsyncMock()
+    db_writer.redis_update_buffer = mock_redis_update_buffer
+
+    mock_pod_lock_manager = AsyncMock()
+    mock_pod_lock_manager.acquire_lock = AsyncMock(return_value=True)
+    mock_pod_lock_manager.release_lock = AsyncMock()
+    db_writer.pod_lock_manager = mock_pod_lock_manager
+
+    with patch.object(
+        DBSpendUpdateWriter,
+        "update_daily_tag_spend",
+        new=AsyncMock(side_effect=Exception("db down")),
+    ):
+        await db_writer._commit_daily_tag_spend_to_db_with_redis(
+            prisma_client=MagicMock(),
+            n_retry_times=0,
+            proxy_logging_obj=MagicMock(),
+        )
+
+    mock_redis_update_buffer.restore_transactions_to_redis.assert_awaited_once_with(
+        daily_tag_spend_update_transactions=daily_tag,
+    )
+    mock_pod_lock_manager.release_lock.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_commit_daily_tag_spend_no_requeue_on_success():
+    """A successful daily tag commit must not re-queue anything."""
+    db_writer = DBSpendUpdateWriter()
+
+    daily_tag = {"tag_key1": {"spend": 1.5, "api_requests": 1}}
+
+    mock_redis_update_buffer = AsyncMock()
+    mock_redis_update_buffer.store_in_memory_daily_tag_spend_updates_in_redis = AsyncMock()
+    mock_redis_update_buffer.get_all_daily_tag_spend_update_transactions_from_redis_buffer = AsyncMock(
+        return_value=daily_tag
+    )
+    mock_redis_update_buffer.restore_transactions_to_redis = AsyncMock()
+    db_writer.redis_update_buffer = mock_redis_update_buffer
+
+    mock_pod_lock_manager = AsyncMock()
+    mock_pod_lock_manager.acquire_lock = AsyncMock(return_value=True)
+    mock_pod_lock_manager.release_lock = AsyncMock()
+    db_writer.pod_lock_manager = mock_pod_lock_manager
+
+    with patch.object(
+        DBSpendUpdateWriter,
+        "update_daily_tag_spend",
+        new=AsyncMock(),
+    ):
+        await db_writer._commit_daily_tag_spend_to_db_with_redis(
+            prisma_client=MagicMock(),
+            n_retry_times=0,
+            proxy_logging_obj=MagicMock(),
+        )
+
+    mock_redis_update_buffer.restore_transactions_to_redis.assert_not_awaited()
+    mock_pod_lock_manager.release_lock.assert_awaited_once()
+
+
 @pytest.mark.parametrize(
     "bucket_name,input_dict,table_attr,method_name,where_key,expected_order",
     [
diff --git a/tests/test_litellm/proxy/management_endpoints/test_auto_router_endpoints.py b/tests/test_litellm/proxy/management_endpoints/test_auto_router_endpoints.py
index 16e82bc3bda..dbde7c461b8 100644
--- a/tests/test_litellm/proxy/management_endpoints/test_auto_router_endpoints.py
+++ b/tests/test_litellm/proxy/management_endpoints/test_auto_router_endpoints.py
@@ -559,7 +559,7 @@ def _start_request(**overrides: object) -> StartShadowEvalRequest:
 @pytest.mark.asyncio
 async def test_start_shadow_eval_creates_job_and_frees_expired_or_exhausted_ones(monkeypatch: pytest.MonkeyPatch):
     """Expiry and turn-budget exhaustion both end sampling on their own; either must
-    release the one-active-per-key index so a new eval can start."""
+    release the key's slot in the active-job index so a new eval can start."""
     import litellm.proxy.proxy_server as proxy_server
 
     prisma = _shadow_prisma()
@@ -592,8 +592,21 @@ async def test_start_shadow_eval_creates_job_and_frees_expired_or_exhausted_ones
         (ADMIN, {"judge_model": "not/a real model!"}, None, 400),
         (ADMIN, {"judge_model": "my-router"}, None, 400),
         (ADMIN, {}, "active", 409),
+        (ADMIN, {"direction": "reverse", "baseline_model": "my-router"}, None, 400),
+        (ADMIN, {"direction": "reverse", "baseline_model": "not/a real model!"}, None, 400),
+        (ADMIN, {"direction": "reverse", "baseline_model": "openai/gpt-4o", "router_name": "not-a-router"}, None, 400),
+    ],
+    ids=[
+        "non-admin",
+        "view-only",
+        "unknown-router",
+        "unresolvable-judge",
+        "router-as-judge",
+        "already-active",
+        "router-as-baseline",
+        "unresolvable-baseline",
+        "reverse-still-needs-an-auto-router",
     ],
-    ids=["non-admin", "view-only", "unknown-router", "unresolvable-judge", "router-as-judge", "already-active"],
 )
 async def test_start_shadow_eval_rejections(
     monkeypatch: pytest.MonkeyPatch, caller, request_overrides, active, expected_status
@@ -609,6 +622,68 @@ async def test_start_shadow_eval_rejections(
     assert exc.value.status_code == expected_status
 
 
+@pytest.mark.parametrize(
+    "overrides",
+    [
+        {"direction": "reverse"},
+        {"baseline_model": "openai/gpt-4o"},
+        {"direction": "sideways", "baseline_model": "openai/gpt-4o"},
+    ],
+    ids=["reverse-without-baseline", "forward-with-baseline", "unknown-direction"],
+)
+def test_start_request_pins_baseline_model_to_reverse(overrides):
+    """A forward job has no second arm to name and a reverse job cannot run without one,
+    so neither shape reaches the endpoint to be half-validated there."""
+    with pytest.raises(ValidationError):
+        _start_request(**overrides)
+
+
+@pytest.mark.asyncio
+async def test_start_shadow_eval_reverse_records_its_arms_and_holds_its_own_slot(monkeypatch: pytest.MonkeyPatch):
+    """The two directions ask opposite questions of the same key, so a forward job holding
+    the slot must not block a reverse one. The second reverse start still 409s."""
+    import litellm.proxy.proxy_server as proxy_server
+
+    prisma = _shadow_prisma()
+    active = {"forward": _job_record()}
+    prisma.db.litellm_shadowevaljob.find_first = AsyncMock(
+        side_effect=lambda where, **_: active.get(str(where.get("direction")))
+    )
+    prisma.db.litellm_shadowevaljob.create = AsyncMock(
+        return_value=_job_record(direction="reverse", baseline_model="openai/gpt-4o")
+    )
+    monkeypatch.setattr(proxy_server, "prisma_client", prisma)
+    monkeypatch.setattr(proxy_server, "llm_router", _shadow_router())
+
+    reverse = _start_request(direction="reverse", baseline_model="openai/gpt-4o")
+    response = await start_shadow_eval(reverse, ADMIN)
+
+    assert (response.direction, response.baseline_model) == ("reverse", "openai/gpt-4o")
+    create_data = prisma.db.litellm_shadowevaljob.create.call_args.kwargs["data"]
+    assert create_data["direction"] == "reverse"
+    assert create_data["baseline_model"] == "openai/gpt-4o"
+
+    active["reverse"] = _job_record(id="job-2", direction="reverse")
+    with pytest.raises(HTTPException) as exc:
+        await start_shadow_eval(reverse, ADMIN)
+    assert exc.value.status_code == 409
+
+
+@pytest.mark.asyncio
+async def test_start_shadow_eval_forward_leaves_the_baseline_column_empty(monkeypatch: pytest.MonkeyPatch):
+    import litellm.proxy.proxy_server as proxy_server
+
+    prisma = _shadow_prisma()
+    monkeypatch.setattr(proxy_server, "prisma_client", prisma)
+    monkeypatch.setattr(proxy_server, "llm_router", _shadow_router())
+
+    await start_shadow_eval(_start_request(), ADMIN)
+
+    create_data = prisma.db.litellm_shadowevaljob.create.call_args.kwargs["data"]
+    assert create_data["direction"] == "forward"
+    assert create_data["baseline_model"] is None
+
+
 @pytest.mark.asyncio
 async def test_start_shadow_eval_rejects_a_key_this_proxy_does_not_know(monkeypatch: pytest.MonkeyPatch):
     """A typo'd api_key_id would otherwise create a job no traffic can ever match."""
diff --git a/tests/test_litellm/proxy/pass_through_endpoints/test_llm_pass_through_endpoints.py b/tests/test_litellm/proxy/pass_through_endpoints/test_llm_pass_through_endpoints.py
index f631215c03d..8080ca71773 100644
--- a/tests/test_litellm/proxy/pass_through_endpoints/test_llm_pass_through_endpoints.py
+++ b/tests/test_litellm/proxy/pass_through_endpoints/test_llm_pass_through_endpoints.py
@@ -8,7 +8,7 @@ from unittest.mock import AsyncMock, MagicMock, Mock, patch
 
 import httpx
 import pytest
-from fastapi import Request, Response
+from fastapi import HTTPException, Request, Response
 from fastapi.testclient import TestClient
 
 sys.path.insert(
@@ -19,10 +19,13 @@ import litellm
 from litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints import (
     BaseOpenAIPassThroughHandler,
     RouteChecks,
+    azure_proxy_route,
     bedrock_llm_proxy_route,
     create_pass_through_route,
     cursor_proxy_route,
+    get_azure_ai_search_index_from_endpoint,
     get_vertex_base_url,
+    is_azure_ai_search_service_level_index_create,
     llm_passthrough_factory_proxy_route,
     milvus_proxy_route,
     mistral_proxy_route,
@@ -31,7 +34,7 @@ from litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints import (
     vertex_proxy_route,
     vllm_proxy_route,
 )
-from litellm.proxy._types import UserAPIKeyAuth
+from litellm.proxy._types import LitellmUserRoles, UserAPIKeyAuth
 from litellm.types.passthrough_endpoints.vertex_ai import VertexPassThroughCredentials
 
 
@@ -3249,3 +3252,221 @@ def test_is_passthrough_request_streaming_tolerates_non_object_bodies(request_bo
     )
 
     assert is_passthrough_request_streaming(request_body) is expected
+
+
+class TestGetAzureAISearchIndexFromEndpoint:
+    """The operable index is only the segment right after ``indexes``.
+
+    A doc-write path ends in ``.../docs/index``; the trailing ``index`` must not
+    be mistaken for the target, otherwise a caller could be authorized on one
+    index while Azure applies the write to another.
+    """
+
+    @pytest.mark.parametrize(
+        "endpoint, expected",
+        [
+            ("indexes/my-index/docs/index", "my-index"),
+            ("indexes/my-index/docs/search", "my-index"),
+            ("indexes/my-index", "my-index"),
+            ("indexes/my-index?api-version=2024-07-01", "my-index"),
+            ("/indexes/my-index/docs/index", "my-index"),
+            ("indexes/victim/docs/index", "victim"),
+            ("openai/deployments/gpt-4o/chat/completions", None),
+            ("indexes", None),
+            ("indexes/", None),
+        ],
+    )
+    def test_extracts_positional_index_only(self, endpoint, expected):
+        assert get_azure_ai_search_index_from_endpoint(endpoint) == expected
+
+
+class TestAzureProxyRouteCrossIndexAuthorization:
+    """Regression tests: the passthrough must authorize the index that the request
+    actually targets (the ``/indexes/{name}`` segment), never a different segment
+    that merely happens to match a managed index the caller can access.
+    """
+
+    def _request(self, method: str, path: str) -> MagicMock:
+        request = MagicMock(spec=Request)
+        request.method = method
+        request.headers = {"content-type": "application/json"}
+        request.url = MagicMock()
+        request.url.path = path
+        return request
+
+    @pytest.mark.asyncio
+    async def test_authorizes_the_targeted_index(self):
+        index_object = MagicMock()
+        index_object.litellm_params.vector_store_name = "my-store"
+        vector_store = {"litellm_params": {"api_base": "https://svc.search.windows.net"}}
+
+        with (
+            patch("litellm.proxy.proxy_server.llm_router", MagicMock()),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.is_passthrough_request_using_router_model",
+                return_value=False,
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.ProviderConfigManager.get_provider_vector_stores_config"
+            ) as mock_get_config,
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.is_allowed_to_call_vector_store_endpoint"
+            ) as mock_is_allowed,
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.assert_user_can_access_vector_store",
+                new=AsyncMock(),
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.BaseOpenAIPassThroughHandler._base_openai_pass_through_handler",
+                new=AsyncMock(return_value=Response()),
+            ),
+            patch.object(litellm, "vector_store_index_registry") as mock_index_registry,
+            patch.object(litellm, "vector_store_registry") as mock_vector_registry,
+        ):
+            mock_get_config.return_value.get_auth_credentials.return_value = {"headers": {"api-key": "k"}}
+            mock_index_registry.is_vector_store_index.side_effect = lambda vector_store_index_name: (
+                vector_store_index_name == "my-index"
+            )
+            mock_index_registry.get_vector_store_index_by_name.return_value = index_object
+            mock_vector_registry.get_litellm_managed_vector_store_from_registry_by_name.return_value = vector_store
+
+            await azure_proxy_route(
+                endpoint="indexes/my-index/docs/index",
+                request=self._request("POST", "/azure_ai/indexes/my-index/docs/index"),
+                fastapi_response=MagicMock(spec=Response),
+                user_api_key_dict=MagicMock(spec=UserAPIKeyAuth),
+            )
+
+            mock_is_allowed.assert_called_once()
+            assert mock_is_allowed.call_args.kwargs["index_name"] == "my-index"
+            mock_index_registry.get_vector_store_index_by_name.assert_called_once_with(
+                vector_store_index_name="my-index"
+            )
+
+    @pytest.mark.asyncio
+    async def test_trailing_index_segment_does_not_authorize_a_different_index(self):
+        with (
+            patch("litellm.proxy.proxy_server.llm_router", MagicMock()),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.is_passthrough_request_using_router_model",
+                return_value=False,
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.is_allowed_to_call_vector_store_endpoint"
+            ) as mock_is_allowed,
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.get_secret_str",
+                return_value="https://azure-openai.example.com",
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.passthrough_endpoint_router.get_credentials",
+                return_value="azure-key",
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.BaseOpenAIPassThroughHandler._base_openai_pass_through_handler",
+                new=AsyncMock(return_value=Response()),
+            ) as mock_handler,
+            patch.object(litellm, "vector_store_index_registry") as mock_index_registry,
+        ):
+            mock_index_registry.is_vector_store_index.side_effect = lambda vector_store_index_name: (
+                vector_store_index_name == "index"
+            )
+
+            await azure_proxy_route(
+                endpoint="indexes/victim/docs/index",
+                request=self._request("POST", "/azure_ai/indexes/victim/docs/index"),
+                fastapi_response=MagicMock(spec=Response),
+                user_api_key_dict=MagicMock(spec=UserAPIKeyAuth),
+            )
+
+            mock_is_allowed.assert_not_called()
+            mock_handler.assert_awaited_once()
+            assert mock_handler.await_args.kwargs["custom_llm_provider"] == litellm.LlmProviders.AZURE
+
+
+class TestAzureProxyRouteServiceLevelIndexCreate:
+    """``POST /indexes`` carries no index name, so the managed-index branch cannot
+    claim it and it would otherwise reach the generic Azure passthrough on the
+    proxy's own credential. The admin-only index management guard has to be
+    enforced on the route itself, not just on the permission gate the route skips.
+    """
+
+    def _request(self, method: str, path: str) -> MagicMock:
+        request = MagicMock(spec=Request)
+        request.method = method
+        request.headers = {"content-type": "application/json"}
+        request.url = MagicMock()
+        request.url.path = path
+        return request
+
+    @pytest.mark.parametrize(
+        "method, endpoint, expected",
+        [
+            ("POST", "indexes", True),
+            ("POST", "indexes?api-version=2024-07-01", True),
+            ("POST", "/indexes/", True),
+            ("POST", "indexes/my-index", False),
+            ("POST", "indexes/my-index/docs/index", False),
+            ("GET", "indexes", False),
+            ("POST", "openai/deployments/gpt-4o/chat/completions", False),
+        ],
+    )
+    def test_recognizes_service_level_create(self, method, endpoint, expected):
+        assert is_azure_ai_search_service_level_index_create(method=method, endpoint=endpoint) is expected
+
+    @pytest.mark.asyncio
+    async def test_non_admin_cannot_create_an_index(self):
+        with (
+            patch("litellm.proxy.proxy_server.llm_router", MagicMock()),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.get_secret_str",
+                return_value="https://svc.search.windows.net",
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.BaseOpenAIPassThroughHandler._base_openai_pass_through_handler",
+                new=AsyncMock(return_value=Response()),
+            ) as mock_handler,
+        ):
+            with pytest.raises(HTTPException) as exc_info:
+                await azure_proxy_route(
+                    endpoint="indexes?api-version=2024-07-01",
+                    request=self._request("POST", "/azure_ai/indexes"),
+                    fastapi_response=MagicMock(spec=Response),
+                    user_api_key_dict=UserAPIKeyAuth(
+                        token="sk-team-token",
+                        user_role=LitellmUserRoles.INTERNAL_USER,
+                    ),
+                )
+
+            assert exc_info.value.status_code == 403
+            assert "Only proxy admins can create" in exc_info.value.detail
+            mock_handler.assert_not_awaited()
+
+    @pytest.mark.asyncio
+    async def test_admin_can_still_create_an_index(self):
+        with (
+            patch("litellm.proxy.proxy_server.llm_router", MagicMock()),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.get_secret_str",
+                return_value="https://svc.search.windows.net",
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.passthrough_endpoint_router.get_credentials",
+                return_value="azure-key",
+            ),
+            patch(
+                "litellm.proxy.pass_through_endpoints.llm_passthrough_endpoints.BaseOpenAIPassThroughHandler._base_openai_pass_through_handler",
+                new=AsyncMock(return_value=Response()),
+            ) as mock_handler,
+        ):
+            await azure_proxy_route(
+                endpoint="indexes?api-version=2024-07-01",
+                request=self._request("POST", "/azure_ai/indexes"),
+                fastapi_response=MagicMock(spec=Response),
+                user_api_key_dict=UserAPIKeyAuth(
+                    token="sk-admin-token",
+                    user_role=LitellmUserRoles.PROXY_ADMIN,
+                ),
+            )
+
+            mock_handler.assert_awaited_once()
diff --git a/tests/test_litellm/proxy/vector_store_endpoints/test_vector_store_endpoints.py b/tests/test_litellm/proxy/vector_store_endpoints/test_vector_store_endpoints.py
index 02ca64e5fb8..20b2f68bb0c 100644
--- a/tests/test_litellm/proxy/vector_store_endpoints/test_vector_store_endpoints.py
+++ b/tests/test_litellm/proxy/vector_store_endpoints/test_vector_store_endpoints.py
@@ -2928,3 +2928,187 @@ class TestUpdateVectorStoreAccessControlAndRedaction:
         params = response["vector_store"]["litellm_params"]
         assert params["api_key"] == REDACTED_BY_LITELM_STRING
         assert params["api_base"] == "https://api.openai.com/v1"
+
+
+class TestAzureAIDocumentWritePassthroughPermission:
+    """Regression tests for the Azure AI Search passthrough write mapping.
+
+    Azure's batch document write/merge/delete endpoint is
+    ``POST /indexes/{name}/docs/index``. A non-admin team holding a ``write``
+    grant on the index must be allowed to call it, while index lifecycle
+    (create / update / delete the index itself) stays proxy-admin only.
+
+    These exercise the real ``AzureAIVectorStoreConfig`` endpoint map on
+    purpose (no mocked provider config), so reverting the map to the old
+    ``("PUT", "/docs")`` entry makes ``test_team_with_write_grant_can_upload``
+    fail.
+    """
+
+    INDEX = "my-index"
+
+    READ_ROUTES = [
+        ("GET", f"/azure_ai/indexes/{INDEX}/stats"),
+        ("GET", f"/azure_ai/indexes/{INDEX}/docs"),
+        ("GET", f"/azure_ai/indexes/{INDEX}/docs/$count"),
+        ("GET", f"/azure_ai/indexes/{INDEX}/docs/seed-doc-1"),
+        ("GET", f"/azure_ai/indexes/{INDEX}/docs/suggest"),
+        ("GET", f"/azure_ai/indexes/{INDEX}/docs/autocomplete"),
+        ("POST", f"/azure_ai/indexes/{INDEX}/docs/suggest"),
+        ("POST", f"/azure_ai/indexes/{INDEX}/docs/autocomplete"),
+        ("POST", f"/azure_ai/indexes/{INDEX}/analyze"),
+    ]
+
+    def _request(self, method: str, path: str) -> MagicMock:
+        request = MagicMock(spec=Request)
+        request.method = method
+        request.url.path = path
+        return request
+
+    def _team_member(self, permissions: list) -> MagicMock:
+        user = MagicMock(spec=UserAPIKeyAuth)
+        user.user_role = None
+        user.metadata = {"allowed_vector_store_indexes": [{"index_name": self.INDEX, "index_permissions": permissions}]}
+        user.team_metadata = None
+        return user
+
+    def test_team_with_write_grant_can_upload(self):
+        result = is_allowed_to_call_vector_store_endpoint(
+            provider=LlmProviders.AZURE_AI,
+            index_name=self.INDEX,
+            request=self._request("POST", f"/azure_ai/indexes/{self.INDEX}/docs/index"),
+            user_api_key_dict=self._team_member(["read", "write"]),
+        )
+        assert result is True
+
+    def test_team_without_write_grant_cannot_upload(self):
+        with pytest.raises(HTTPException) as exc_info:
+            is_allowed_to_call_vector_store_endpoint(
+                provider=LlmProviders.AZURE_AI,
+                index_name=self.INDEX,
+                request=self._request("POST", f"/azure_ai/indexes/{self.INDEX}/docs/index"),
+                user_api_key_dict=self._team_member(["read"]),
+            )
+        assert exc_info.value.status_code == 403
+
+    def test_team_with_read_grant_can_search(self):
+        result = is_allowed_to_call_vector_store_endpoint(
+            provider=LlmProviders.AZURE_AI,
+            index_name=self.INDEX,
+            request=self._request("POST", f"/azure_ai/indexes/{self.INDEX}/docs/search"),
+            user_api_key_dict=self._team_member(["read"]),
+        )
+        assert result is True
+
+    def test_team_with_read_grant_can_get_index_details(self):
+        result = is_allowed_to_call_vector_store_endpoint(
+            provider=LlmProviders.AZURE_AI,
+            index_name=self.INDEX,
+            request=self._request("GET", f"/azure_ai/indexes/{self.INDEX}"),
+            user_api_key_dict=self._team_member(["read"]),
+        )
+        assert result is True
+
+    def test_team_without_read_grant_cannot_get_index_details(self):
+        with pytest.raises(HTTPException) as exc_info:
+            is_allowed_to_call_vector_store_endpoint(
+                provider=LlmProviders.AZURE_AI,
+                index_name=self.INDEX,
+                request=self._request("GET", f"/azure_ai/indexes/{self.INDEX}"),
+                user_api_key_dict=self._team_member(["write"]),
+            )
+        assert exc_info.value.status_code == 403
+
+    @pytest.mark.parametrize("method, path", READ_ROUTES)
+    def test_team_with_read_grant_can_call_every_read_route(self, method, path):
+        result = is_allowed_to_call_vector_store_endpoint(
+            provider=LlmProviders.AZURE_AI,
+            index_name=self.INDEX,
+            request=self._request(method, path),
+            user_api_key_dict=self._team_member(["read"]),
+        )
+        assert result is True
+
+    @pytest.mark.parametrize("method, path", READ_ROUTES)
+    def test_team_without_read_grant_cannot_call_read_routes(self, method, path):
+        with pytest.raises(HTTPException) as exc_info:
+            is_allowed_to_call_vector_store_endpoint(
+                provider=LlmProviders.AZURE_AI,
+                index_name=self.INDEX,
+                request=self._request(method, path),
+                user_api_key_dict=self._team_member(["write"]),
+            )
+        assert exc_info.value.status_code == 403
+
+    @pytest.mark.parametrize(
+        "method, operation, path",
+        [
+            ("PUT", "update", f"/azure_ai/indexes/{INDEX}?api-version=2024-07-01"),
+            ("DELETE", "delete", f"/azure_ai/indexes/{INDEX}?api-version=2024-07-01"),
+            ("POST", "create", "/azure_ai/indexes?api-version=2024-07-01"),
+        ],
+    )
+    def test_team_cannot_manage_index_lifecycle_even_with_write_grant(self, method, operation, path):
+        with pytest.raises(HTTPException) as exc_info:
+            is_allowed_to_call_vector_store_endpoint(
+                provider=LlmProviders.AZURE_AI,
+                index_name=self.INDEX,
+                request=self._request(method, path),
+                user_api_key_dict=self._team_member(["read", "write"]),
+            )
+        assert exc_info.value.status_code == 403
+        assert f"Only proxy admins can {operation}" in exc_info.value.detail
+
+
+class TestAzureAIAnalyzeNamedIndexClassification:
+    """Regression tests for write-before-read endpoint classification.
+
+    The endpoint matcher is substring-based, so the batch-write path of an
+    index named ``analyze*`` contains the ``("POST", "/analyze")`` read
+    fragment. Reads-first classification labeled that write a read, letting a
+    read-only grant upload, merge, and delete documents (and refusing
+    legitimate write-only grants). Writes are classified first now, so an
+    ambiguous path demands the stronger grant.
+    """
+
+    def _request(self, method: str, path: str) -> MagicMock:
+        request = MagicMock(spec=Request)
+        request.method = method
+        request.url.path = path
+        return request
+
+    def _team_member(self, index: str, permissions: list) -> MagicMock:
+        user = MagicMock(spec=UserAPIKeyAuth)
+        user.user_role = None
+        user.metadata = {"allowed_vector_store_indexes": [{"index_name": index, "index_permissions": permissions}]}
+        user.team_metadata = None
+        return user
+
+    @pytest.mark.parametrize("index", ["analyze", "analyzer-reports"])
+    def test_read_only_grant_cannot_upload_to_analyze_named_index(self, index):
+        with pytest.raises(HTTPException) as exc_info:
+            is_allowed_to_call_vector_store_endpoint(
+                provider=LlmProviders.AZURE_AI,
+                index_name=index,
+                request=self._request("POST", f"/azure_ai/indexes/{index}/docs/index"),
+                user_api_key_dict=self._team_member(index, ["read"]),
+            )
+        assert exc_info.value.status_code == 403
+
+    @pytest.mark.parametrize("index", ["analyze", "analyzer-reports"])
+    def test_write_grant_can_upload_to_analyze_named_index(self, index):
+        result = is_allowed_to_call_vector_store_endpoint(
+            provider=LlmProviders.AZURE_AI,
+            index_name=index,
+            request=self._request("POST", f"/azure_ai/indexes/{index}/docs/index"),
+            user_api_key_dict=self._team_member(index, ["write"]),
+        )
+        assert result is True
+
+    def test_read_only_grant_can_still_analyze_on_analyze_named_index(self):
+        result = is_allowed_to_call_vector_store_endpoint(
+            provider=LlmProviders.AZURE_AI,
+            index_name="analyze",
+            request=self._request("POST", "/azure_ai/indexes/analyze/analyze"),
+            user_api_key_dict=self._team_member("analyze", ["read"]),
+        )
+        assert result is True
diff --git a/tests/test_litellm/responses/mcp/test_litellm_proxy_mcp_handler.py b/tests/test_litellm/responses/mcp/test_litellm_proxy_mcp_handler.py
index 4981caa10c3..87525273911 100644
--- a/tests/test_litellm/responses/mcp/test_litellm_proxy_mcp_handler.py
+++ b/tests/test_litellm/responses/mcp/test_litellm_proxy_mcp_handler.py
@@ -28,6 +28,7 @@ def _setup_mcp_call_environment(monkeypatch: pytest.MonkeyPatch) -> AsyncMock:
     monkeypatch.setitem(sys.modules, "litellm.proxy.proxy_server", proxy_module)
 
     fake_manager = types.SimpleNamespace(
+        get_registry=MagicMock(return_value={}),
         call_tool=AsyncMock(return_value=_DummyMCPResult()),
         # Newer logging path calls this to enrich spend logs metadata
         _get_mcp_server_from_tool_name=MagicMock(return_value=None),
@@ -373,6 +374,7 @@ async def test_execute_tool_calls_logs_failure_via_post_call_failure_hook(monkey
     post_call_failure_hook = _setup_proxy_logging(monkeypatch)
 
     fake_manager = types.SimpleNamespace(
+        get_registry=MagicMock(return_value={}),
         call_tool=AsyncMock(side_effect=HTTPException(status_code=500, detail="boom"))
     )
     monkeypatch.setattr(
@@ -464,6 +466,7 @@ async def test_get_mcp_tools_from_manager_enables_list_tools_logging(monkeypatch
 
     # Patch manager methods used by _get_mcp_tools_from_manager to avoid needing full UserAPIKeyAuth fields.
     fake_manager = types.SimpleNamespace(
+        get_registry=MagicMock(return_value={}),
         get_allowed_mcp_servers=AsyncMock(return_value=[]),
         get_mcp_servers_from_ids=MagicMock(return_value=[]),
         get_mcp_server_by_name=MagicMock(return_value=None),
@@ -516,6 +519,7 @@ async def test_get_mcp_tools_from_manager_forwards_request_tags(monkeypatch):
         mock_get_tools,
     )
     fake_manager = types.SimpleNamespace(
+        get_registry=MagicMock(return_value={}),
         get_allowed_mcp_servers=AsyncMock(return_value=[]),
         get_mcp_servers_from_ids=MagicMock(return_value=[]),
         get_mcp_server_by_name=MagicMock(return_value=None),
diff --git a/tests/test_litellm/responses/mcp/test_mcp_streaming_iterator.py b/tests/test_litellm/responses/mcp/test_mcp_streaming_iterator.py
index 24edf12fffe..aacd614abb9 100644
--- a/tests/test_litellm/responses/mcp/test_mcp_streaming_iterator.py
+++ b/tests/test_litellm/responses/mcp/test_mcp_streaming_iterator.py
@@ -69,6 +69,7 @@ def _mock_mcp_environment(monkeypatch: pytest.MonkeyPatch) -> AsyncMock:
     """Patch the MCP tool-call plumbing so _execute_tool_calls can run in tests."""
     call_tool = AsyncMock(return_value=CallToolResult(content=[TextContent(type="text", text="ok")], isError=False))
     fake_manager = types.SimpleNamespace(
+        get_registry=MagicMock(return_value={}),
         call_tool=call_tool,
         _get_mcp_server_from_tool_name=MagicMock(return_value=None),
         get_mcp_server_by_name=MagicMock(return_value=None),
diff --git a/type-discipline-budget.json b/type-discipline-budget.json
index 894d99c92e0..94565199516 100644
--- a/type-discipline-budget.json
+++ b/type-discipline-budget.json
@@ -1,6 +1,6 @@
 {
   "LIT001": {
-    "limit": 22941
+    "limit": 22938
   },
   "LIT002": {
     "limit": 27139
diff --git a/ui/litellm-dashboard/public/assets/logos/nimble.png b/ui/litellm-dashboard/public/assets/logos/nimble.png
new file mode 100644
index 00000000000..6ad2ff611e7
Binary files /dev/null and b/ui/litellm-dashboard/public/assets/logos/nimble.png differ
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.test.tsx b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.test.tsx
index 467439122dd..d4d26650086 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.test.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.test.tsx
@@ -358,6 +358,7 @@ describe("ShadowEvalSection", () => {
     const expectedBody = {
       api_key_id: "hash-alpha",
       router_name: "gpt-auto",
+      direction: "forward",
       shadow_percentage: 10,
       duration_days: 7,
       max_turns: 200,
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.tsx b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.tsx
index 6bb00933218..711fc1af539 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/cost-optimization/_components/ShadowEvalSection.tsx
@@ -308,6 +308,7 @@ const StartForm: React.FC = () => {
     const startBody = {
       api_key_id: apiKeyId,
       router_name: routerName,
+      direction: "forward" as const,
       shadow_percentage: parsedPct,
       duration_days: Number.parseInt(durationDays, 10),
       max_turns: parsedMaxTurns,
diff --git a/ui/litellm-dashboard/src/app/(dashboard)/search-tools/_components/CreateSearchTools.tsx b/ui/litellm-dashboard/src/app/(dashboard)/search-tools/_components/CreateSearchTools.tsx
index 1eeff00cb1b..6c8cef0b1a1 100644
--- a/ui/litellm-dashboard/src/app/(dashboard)/search-tools/_components/CreateSearchTools.tsx
+++ b/ui/litellm-dashboard/src/app/(dashboard)/search-tools/_components/CreateSearchTools.tsx
@@ -12,6 +12,7 @@ import { AvailableSearchProvider, SearchTool } from "./types";
 import dataforseoLogo from "../../../../../public/assets/logos/dataforseo.png";
 import exaAiLogo from "../../../../../public/assets/logos/exa_ai.png";
 import googlePseLogo from "../../../../../public/assets/logos/google_pse.png";
+import nimbleLogo from "../../../../../public/assets/logos/nimble.png";
 import parallelAiLogo from "../../../../../public/assets/logos/parallel_ai.png";
 import perplexityLogo from "../../../../../public/assets/logos/perplexity.png";
 import tavilyLogo from "../../../../../public/assets/logos/tavily.png";
@@ -25,6 +26,7 @@ const searchProviderLogoMap: Record<string, string> = {
   exa_ai: exaAiLogo.src,
   google_pse: googlePseLogo.src,
   dataforseo: dataforseoLogo.src,
+  nimble: nimbleLogo.src,
 };
 
 interface SearchProviderLabelProps {
diff --git a/ui/litellm-dashboard/src/lib/http/schema.d.ts b/ui/litellm-dashboard/src/lib/http/schema.d.ts
index 2cbc7fd6220..eeea16f3ccd 100644
--- a/ui/litellm-dashboard/src/lib/http/schema.d.ts
+++ b/ui/litellm-dashboard/src/lib/http/schema.d.ts
@@ -838,9 +838,15 @@ export interface paths {
         put?: never;
         /**
          * Start Shadow Eval
-         * @description Start a pre-adoption shadow eval: duplicate a sampled slice of a key's live traffic
-         *     through an auto-router, judge real vs. shadow responses blind, and stratify win rates
-         *     by the router's tier classification and by the incumbent model.
+         * @description Start a shadow eval: duplicate a sampled slice of a key's live traffic against a second
+         *     arm, judge the two responses blind, and stratify win rates by tier and by the model that
+         *     served the real arm.
+         *
+         *     A forward job answers whether the key should adopt router_name: it samples the requests
+         *     the router did not serve and duplicates them through it. A reverse job answers whether a
+         *     key already on the router still gains from it: it samples the requests the router did
+         *     serve and duplicates them against baseline_model. A key can hold one active job per
+         *     direction, so both questions can run at once.
          *
          *     Shadow responses are never served to users. The job samples until it has judged
          *     max_turns turns, reaches the end of its window, or is stopped; sampling changes
@@ -32737,11 +32743,19 @@ export interface components {
              * @description The hashed virtual key whose traffic this job evaluates, and only that key's
              */
             api_key_id: string;
+            /** Baseline Model */
+            baseline_model?: string | null;
             /**
              * Created At
              * Format: date-time
              */
             created_at: string;
+            /**
+             * Direction
+             * @default forward
+             * @enum {string}
+             */
+            direction: "forward" | "reverse";
             /**
              * Ends At
              * Format: date-time
@@ -32794,7 +32808,10 @@ export interface components {
          * @description Stratified results of a shadow-eval job's verdicts so far.
          */
         ShadowEvalResult: {
-            /** By Current Model */
+            /**
+             * By Current Model
+             * @description Sliced by the model that served the real arm: the key's incumbent models in forward mode, and in reverse the models the router itself picked
+             */
             by_current_model: components["schemas"]["ShadowEvalSlice"][];
             /** By Tier */
             by_tier: components["schemas"]["ShadowEvalSlice"][];
@@ -32806,7 +32823,7 @@ export interface components {
         /**
          * ShadowEvalSlice
          * @description Judge outcomes for one slice of a job's verdicts (a router tier, or one of the
-         *     models the shadowed key currently uses).
+         *     models that served the real arm).
          */
         ShadowEvalSlice: {
             /** Avg Judge Confidence */
@@ -32815,12 +32832,12 @@ export interface components {
             group: string;
             /**
              * Real Win Rate Pct
-             * @description Share of judged turns where the real (control) model won
+             * @description Share of judged turns the real arm won, meaning the response the caller actually received: the key's own model in forward mode, the router's pick in reverse
              */
             real_win_rate_pct: number;
             /**
              * Shadow Win Rate Pct
-             * @description Share of judged turns where the shadowed router's pick won
+             * @description Share of judged turns the shadow arm won, meaning the duplicated response nobody was served: the router's pick in forward mode, baseline_model in reverse
              */
             shadow_win_rate_pct: number;
             /** Tie Rate Pct */
@@ -33003,7 +33020,7 @@ export interface components {
         };
         /**
          * StartShadowEvalRequest
-         * @description Start shadowing a key's traffic through an auto-router for blind comparison.
+         * @description Start duplicating a key's traffic for blind comparison against an auto-router.
          */
         StartShadowEvalRequest: {
             /**
@@ -33011,6 +33028,18 @@ export interface components {
              * @description The hashed virtual key whose traffic will be shadowed. Shadow evaluation runs ONLY on this key's traffic; requests made with any other key are not sampled.
              */
             api_key_id: string;
+            /**
+             * Baseline Model
+             * @description Required when direction is reverse and rejected otherwise: the fixed model the router's own responses are judged against. Must be a plain model rather than another auto-router
+             */
+            baseline_model?: string | null;
+            /**
+             * Direction
+             * @description forward answers 'should this key adopt router_name': it samples the requests the key did NOT route through the router and duplicates them through it. reverse answers 'is the router still worth it for a key already on it': it samples the requests the router did serve and duplicates them against baseline_model. The response the caller received is always the real arm
+             * @default forward
+             * @enum {string}
+             */
+            direction: "forward" | "reverse";
             /**
              * Duration Days
              * @description How many days the job samples traffic before completing on its own
@@ -33031,7 +33060,7 @@ export interface components {
             max_turns: number;
             /**
              * Router Name
-             * @description The auto-router config to shadow requests through
+             * @description The auto-router under evaluation, in either direction
              */
             router_name: string;
             /**