diff --git a/tests/e2e/batches/batch_client.py b/tests/e2e/batches/batch_client.py
index 5cc5d1dae3b..968a357e8af 100644
--- a/tests/e2e/batches/batch_client.py
+++ b/tests/e2e/batches/batch_client.py
@@ -40,8 +40,15 @@ class FileObject(BaseModel):
 
 
 class FileList(BaseModel):
+    """GET /v1/files page. The cursors are modelled because they are part of the
+    page's isolation contract: they must address rows in `data`, never rows the
+    caller was not allowed to see."""
+
     object: str | None = None
     data: list[FileObject] = []
+    first_id: str | None = None
+    last_id: str | None = None
+    has_more: bool | None = None
 
 
 class BatchObject(BaseModel):
diff --git a/tests/e2e/batches/test_batches_e2e.py b/tests/e2e/batches/test_batches_e2e.py
index 53bf9739983..12b848dd063 100644
--- a/tests/e2e/batches/test_batches_e2e.py
+++ b/tests/e2e/batches/test_batches_e2e.py
@@ -572,6 +572,41 @@ class TestOpenAIFiles:
             f"listed file must round-trip the upload purpose, got {match.purpose!r}"
         )
 
+    @pytest.mark.covers(
+        "llm.files.openai.list_isolation.nonstream.works",
+        exercised_on=["files"],
+    )
+    def test_list_page_cursors_address_only_the_callers_own_files(
+        self, client: BatchClient, resources: ResourceManager
+    ) -> None:
+        """Pins GitHub issue #36087: a list page's pagination cursors must address
+        rows in that page.
+
+        The proxy fronts one shared provider account, so the upstream page is the
+        whole organization's. The gateway narrows `data` to the files the caller
+        owns, and `first_id` / `last_id` have to be narrowed with it: left as the
+        upstream org's, they hand any caller raw provider file ids belonging to
+        other tenants, which is the handle the file routes accept.
+        """
+        key = resources.key(user_id=f"e2e-file-list-{unique_marker()}")
+
+        listed = unwrap(client.list_files(key=key))
+
+        expected_first = listed.data[0].id if listed.data else None
+        expected_last = listed.data[-1].id if listed.data else None
+        assert listed.first_id == expected_first, (
+            f"first_id {listed.first_id!r} is not the first row this caller can see "
+            f"({expected_first!r}); the page leaked another caller's file id"
+        )
+        assert listed.last_id == expected_last, (
+            f"last_id {listed.last_id!r} is not the last row this caller can see "
+            f"({expected_last!r}); the page leaked another caller's file id"
+        )
+        assert listed.has_more is not True, (
+            "the page advertises another page, but the proxy never forwards a cursor "
+            "upstream, so following it re-serves this same page forever"
+        )
+
     @pytest.mark.covers(
         "llm.files.openai.retrieve.nonstream.works",
         exercised_on=["files"],
diff --git a/tests/e2e/coverage_registry/llm_conversational.yaml b/tests/e2e/coverage_registry/llm_conversational.yaml
index 61ce30e3b81..44ed5765e38 100644
--- a/tests/e2e/coverage_registry/llm_conversational.yaml
+++ b/tests/e2e/coverage_registry/llm_conversational.yaml
@@ -63,6 +63,7 @@
 - {id: llm.responses.openai.input_validation.nonstream.works, module: llm, tier: P1, subject_endpoint: responses, route: openai, capability: input_validation, streaming: nonstream, assertions: [works], source: "vendor strategy §9.9 / LIT-4778", rationale: "Responses missing/empty input and missing model are rejected"}
 - {id: llm.responses.openai.basic.stream.works, module: llm, tier: P0, subject_endpoint: responses, route: openai, capability: basic, streaming: stream, assertions: [works], source: "response_api_endpoints/endpoints.py:26", rationale: "Streaming via /v1/responses"}
 - {id: llm.responses.openai.basic.nonstream.cost_logged, module: llm, tier: P0, subject_endpoint: responses, route: openai, capability: basic, streaming: nonstream, assertions: [works, cost_logged], source: "response_api_endpoints/endpoints.py:26", rationale: "Cost logged on responses"}
+- {id: llm.responses.openai.passthrough.stream.cost_logged, module: llm, tier: P0, subject_endpoint: responses, route: openai, capability: basic, streaming: stream, assertions: [cost_logged], source: "test_passthrough_e2e.py", rationale: "A streamed POST /openai_passthrough/v1/responses is costed and keyed by the provider response id; it used to log a zero-cost row under a random id (GitHub issue #36523)"}
 - {id: llm.responses.openai.tool_use.nonstream.works, module: llm, tier: P0, subject_endpoint: responses, route: openai, capability: tool_use, streaming: nonstream, assertions: [works], source: "model_prices json", rationale: "Tool calls via Responses API"}
 - {id: llm.responses.openai.vision.nonstream.works, module: llm, tier: P0, subject_endpoint: responses, route: openai, capability: vision, streaming: nonstream, assertions: [works], source: "model_prices json", rationale: "Vision via Responses API"}
 - {id: llm.responses.anthropic.basic.nonstream.works, module: llm, tier: P1, subject_endpoint: responses, route: anthropic, capability: basic, streaming: nonstream, assertions: [works], source: "response_api_endpoints/endpoints.py:26", rationale: "Responses w/ Anthropic translation (smoke)"}
diff --git a/tests/e2e/coverage_registry/llm_nonconversational.yaml b/tests/e2e/coverage_registry/llm_nonconversational.yaml
index bb7169509eb..8ae7dd01b5a 100644
--- a/tests/e2e/coverage_registry/llm_nonconversational.yaml
+++ b/tests/e2e/coverage_registry/llm_nonconversational.yaml
@@ -3,6 +3,7 @@
 - {id: llm.embeddings.openai.basic.nonstream.works, module: llm, tier: P0, subject_endpoint: embeddings, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_embeddings_endpoint_e2e.py:23", rationale: "Core endpoint, live vector response"}
 - {id: llm.embeddings.openai.input_validation.nonstream.works, module: llm, tier: P1, subject_endpoint: embeddings, route: openai, capability: input_validation, streaming: nonstream, assertions: [works], source: "vendor strategy §9.3 / LIT-4778", rationale: "Missing model/input on /embeddings return client errors"}
 - {id: llm.embeddings.openai.basic.nonstream.cost_logged, module: llm, tier: P0, subject_endpoint: embeddings, route: openai, capability: basic, streaming: nonstream, assertions: [cost_logged], source: "SPEND_TRACKING_COVERAGE_MATRIX.md:34", rationale: "Cost tracking on embeddings"}
+- {id: llm.embeddings.openai.passthrough.nonstream.cost_logged, module: llm, tier: P0, subject_endpoint: embeddings, route: openai, capability: basic, streaming: nonstream, assertions: [cost_logged], source: "test_passthrough_e2e.py", rationale: "POST /openai_passthrough/v1/embeddings is costed; the route wrote no spend row at all, so budgets never saw traffic OpenAI was billing for (GitHub issue #36646)"}
 - {id: llm.embeddings.azure_openai.basic.nonstream.works, module: llm, tier: P0, subject_endpoint: embeddings, route: azure_openai, capability: basic, streaming: nonstream, assertions: [works], source: "llms/azure/azure.py", rationale: "Azure embeddings via translation"}
 - {id: llm.embeddings.bedrock.basic.nonstream.works, module: llm, tier: P1, subject_endpoint: embeddings, route: bedrock_converse, capability: basic, streaming: nonstream, assertions: [works], source: "llms/bedrock/embed/embedding.py", rationale: "Bedrock Titan embeddings"}
 - {id: llm.embeddings.vertex.basic.nonstream.works, module: llm, tier: P1, subject_endpoint: embeddings, route: vertex, capability: basic, streaming: nonstream, assertions: [works], source: "vertex_embeddings/embedding_handler.py", rationale: "Vertex embeddings"}
@@ -13,6 +14,7 @@
 - {id: llm.batches.openai.cancel.nonstream.works, module: llm, tier: P0, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_batches_e2e.py", rationale: "Batch cancel"}
 - {id: llm.batches.openai.list.nonstream.works, module: llm, tier: P0, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_batches_e2e.py", rationale: "Batch list envelope"}
 - {id: llm.batches.openai.file_lifecycle.nonstream.works, module: llm, tier: P0, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_batches_e2e.py", rationale: "File upload/retrieve/delete for batch flow"}
+- {id: llm.batches.openai.passthrough.nonstream.works, module: llm, tier: P1, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_passthrough_e2e.py", rationale: "GET /openai_passthrough/v1/batches relays OpenAI's own batch page; the dedicated prefix must not bind as a provider name on the /{provider}/v1/batches route (GitHub issue #36086)"}
 - {id: llm.batches.openai_encoded.basic.nonstream.works, module: llm, tier: P0, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "batches/capabilities.py", rationale: "Encoded scenario lifecycle"}
 - {id: llm.batches.openai_unified.basic.nonstream.works, module: llm, tier: P0, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "batches/capabilities.py", rationale: "Unified/managed-id scenario"}
 - {id: llm.batches.openai_model_param.basic.nonstream.works, module: llm, tier: P0, subject_endpoint: batches, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "batches/capabilities.py", rationale: "Model-param scenario"}
@@ -29,6 +31,8 @@
 - {id: llm.files.openai.retrieve.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "files_endpoints.py", rationale: "File retrieve by id"}
 - {id: llm.files.openai.delete.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "files_endpoints.py", rationale: "File delete returns deleted=true"}
 - {id: llm.files.openai.list.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "files_endpoints.py", rationale: "File list paginated"}
+- {id: llm.files.openai.list_isolation.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_batches_e2e.py", rationale: "GET /v1/files pagination cursors address only rows the caller owns; on a shared provider account the upstream cursors otherwise hand out other tenants' raw provider file ids (GitHub issue #36087)"}
+- {id: llm.files.openai.passthrough.nonstream.works, module: llm, tier: P1, subject_endpoint: files, route: openai, capability: basic, streaming: nonstream, assertions: [works], source: "test_passthrough_e2e.py", rationale: "POST/DELETE /openai_passthrough/v1/files relay OpenAI's own file object; the dedicated prefix must not bind as a provider name on the /{provider}/v1/files route (GitHub issue #36086)"}
 - {id: llm.files.azure_openai.upload.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: azure_openai, capability: basic, streaming: nonstream, assertions: [works], source: "batches/capabilities.py:45", rationale: "Azure file upload managed backend"}
 - {id: llm.files.vertex.upload.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: vertex, capability: basic, streaming: nonstream, assertions: [works], source: "batches/capabilities.py:52", rationale: "Vertex file upload to GCS"}
 - {id: llm.files.bedrock.upload.nonstream.works, module: llm, tier: P0, subject_endpoint: files, route: bedrock_converse, capability: basic, streaming: nonstream, assertions: [works], source: "batches/capabilities.py:59", rationale: "Bedrock file upload to S3"}
diff --git a/tests/e2e/lifecycle.py b/tests/e2e/lifecycle.py
index 4ef25509905..c9a67ebdb8c 100644
--- a/tests/e2e/lifecycle.py
+++ b/tests/e2e/lifecycle.py
@@ -52,7 +52,7 @@ class ResourceManager:
     """
 
     client: ResourceClient
-    _cleanups: List[Callable[[], None]] = field(
+    _cleanups: List[Callable[[], object]] = field(
         default_factory=list
     )  # mutable-ok: append-only teardown registry
 
@@ -60,8 +60,11 @@ class ResourceManager:
         """No global setup needed today; present for lifecycle symmetry."""
         return None
 
-    def defer(self, cleanup: Callable[[], None]) -> None:
-        """Register a teardown action for any resource the test just created."""
+    def defer(self, cleanup: Callable[[], object]) -> None:
+        """Register a teardown action for any resource the test just created.
+
+        Whatever the action returns is discarded, so a delete that answers with a
+        response model can be deferred directly."""
         self._cleanups.append(cleanup)
 
     def key(self, models: list[str] | None = None, user_id: str | None = "e2e-test-user") -> str:
diff --git a/tests/e2e/llm_translation/passthrough_client.py b/tests/e2e/llm_translation/passthrough_client.py
index 439594f3624..e0dfae679a9 100644
--- a/tests/e2e/llm_translation/passthrough_client.py
+++ b/tests/e2e/llm_translation/passthrough_client.py
@@ -15,7 +15,7 @@ from dataclasses import dataclass
 from pydantic import BaseModel, Field
 
 from proxy_client import ProxyClient
-from e2e_http import Headers, StreamingResponse
+from e2e_http import FileUploadForm, Headers, NoBody, Result, StreamingResponse
 from models import ChatMessage
 
 
@@ -113,6 +113,76 @@ class OpenAIChatBody(BaseModel):
     max_completion_tokens: int = 64
 
 
+class PassthroughFileObject(BaseModel):
+    id: str
+    object: str | None = None
+    purpose: str | None = None
+    filename: str | None = None
+    bytes: int | None = None
+
+
+class PassthroughFileDeleted(BaseModel):
+    id: str
+    deleted: bool
+
+
+class PassthroughListEntry(BaseModel):
+    id: str
+
+
+class ResponsesUsage(BaseModel):
+    input_tokens: int
+    output_tokens: int
+
+
+class ResponsesObject(BaseModel):
+    id: str
+    usage: ResponsesUsage | None = None
+
+
+class ResponsesStreamEvent(BaseModel):
+    """One SSE frame of a native Responses stream. Only the terminal frames carry a
+    `response`, so it stays optional and the deltas validate as themselves."""
+
+    type: str
+    response: ResponsesObject | None = None
+
+
+def completed_responses_object(result: StreamingResponse) -> ResponsesObject | None:
+    """The `response.completed` frame's response object, or None if the stream never
+    completed. Its `id` is what the spend row is keyed by on this route, and its
+    usage is what the row is priced from."""
+    events = (
+        ResponsesStreamEvent.model_validate_json(payload)
+        for payload in result.stream_events
+    )
+    completed = tuple(
+        event.response
+        for event in events
+        if event.type == "response.completed" and event.response is not None
+    )
+    return completed[-1] if completed else None
+
+
+class OpenAIResponsesBody(BaseModel):
+    model: str
+    input: str
+    stream: bool = False
+
+
+class OpenAIEmbeddingBody(BaseModel):
+    model: str
+    input: str
+
+
+class PassthroughBatchList(BaseModel):
+    """OpenAI's own batch page, relayed verbatim. `object` is required so a body
+    that is not an OpenAI list fails validation instead of passing vacuously."""
+
+    object: str
+    data: list[PassthroughListEntry]
+
+
 def _tags_header(tags: list[str] | None) -> str | None:
     return ",".join(tags) if tags else None
 
@@ -196,6 +266,66 @@ class PassthroughClient:
             stream=stream,
         )
 
+    # ---- OpenAI file/batch routes under /openai_passthrough -------------
+    #
+    # Relayed to OpenAI untouched, which is the whole point of the prefix: the
+    # customer opts out of the gateway's managed-file handling here.
+
+    def openai_passthrough_upload_file(
+        self, key: str, *, content: bytes, filename: str
+    ) -> Result[PassthroughFileObject]:
+        return self.proxy.transport.upload(
+            "/openai_passthrough/v1/files",
+            headers=self.proxy.transport.bearer(key),
+            form=FileUploadForm(purpose="batch"),
+            filename=filename,
+            content=content,
+            response_type=PassthroughFileObject,
+        )
+
+    def openai_passthrough_delete_file(
+        self, key: str, file_id: str
+    ) -> Result[PassthroughFileDeleted]:
+        return self.proxy.transport.delete(
+            f"/openai_passthrough/v1/files/{file_id}",
+            headers=self.proxy.transport.bearer(key),
+            json=NoBody(),
+            response_type=PassthroughFileDeleted,
+        )
+
+    def openai_passthrough_list_batches(self, key: str) -> Result[PassthroughBatchList]:
+        return self.proxy.transport.get(
+            "/openai_passthrough/v1/batches",
+            headers=self.proxy.transport.bearer(key),
+            params=NoBody(),
+            response_type=PassthroughBatchList,
+        )
+
+    # ---- OpenAI inference routes under /openai_passthrough -------------
+    #
+    # Relayed to OpenAI verbatim, but still costed by the gateway: the customer
+    # budgets against this traffic, so a 200 that logs no spend is money the
+    # gateway never sees.
+
+    def openai_passthrough_responses(
+        self, key: str, model: str, text: str, *, stream: bool = False
+    ) -> StreamingResponse:
+        return self.proxy.transport.send(
+            "/openai_passthrough/v1/responses",
+            headers=self.proxy.transport.bearer(key),
+            json=OpenAIResponsesBody(model=model, input=text, stream=stream),
+            stream=stream,
+        )
+
+    def openai_passthrough_embed(
+        self, key: str, model: str, text: str
+    ) -> StreamingResponse:
+        return self.proxy.transport.send(
+            "/openai_passthrough/v1/embeddings",
+            headers=self.proxy.transport.bearer(key),
+            json=OpenAIEmbeddingBody(model=model, input=text),
+        )
+
     def openai_chat(
         self, key: str, model: str, text: str, *, max_completion_tokens: int = 64
     ) -> StreamingResponse:
diff --git a/tests/e2e/llm_translation/test_passthrough_e2e.py b/tests/e2e/llm_translation/test_passthrough_e2e.py
index b57164df9bb..17b0dbe1ae5 100644
--- a/tests/e2e/llm_translation/test_passthrough_e2e.py
+++ b/tests/e2e/llm_translation/test_passthrough_e2e.py
@@ -13,8 +13,8 @@ A passthrough call returning non-2xx fails hard (never a skip); once it returns
 
 import pytest
 
-from e2e_config import unique_marker
-from e2e_http import StreamingResponse, require_successful_call
+from e2e_config import CHEAP_OPENAI_MODEL, unique_marker
+from e2e_http import StreamingResponse, require_successful_call, unwrap
 from lifecycle import ResourceManager
 from models import KeyGenerateBody, SpendLogRow
 from passthrough_client import (
@@ -24,8 +24,11 @@ from passthrough_client import (
     JsonSchema,
     JsonSchemaProperty,
     PassthroughClient,
+    completed_responses_object,
 )
 
+EMBEDDING_MODEL = "text-embedding-3-small"
+
 pytestmark = pytest.mark.e2e
 
 
@@ -210,3 +213,129 @@ class TestPassthroughModelAllowlist:
             "a key restricted to gemini-2.5-flash must be denied a claude passthrough call, "
             f"got {result.status_code}: {result.body[:300]}"
         )
+
+
+class TestOpenAIPassthroughPrefix:
+    """The dedicated `/openai_passthrough` prefix must reach OpenAI, not be
+    swallowed by the provider-scoped `/{provider}/v1/...` routes.
+
+    The customer fronts OpenAI's own file and batch APIs through this prefix
+    precisely to opt out of the gateway's managed-file handling. `/v1/files` and
+    `/v1/batches` also answer `/{provider}/v1/files` and `/{provider}/v1/batches`,
+    so `openai_passthrough` used to bind as a provider name and the request died
+    inside the gateway with a provider-lookup error, never reaching OpenAI.
+    """
+
+    @pytest.mark.covers("llm.files.openai.passthrough.nonstream.works")
+    def test_passthrough_prefix_uploads_a_file_to_openai(
+        self, client: PassthroughClient, resources: ResourceManager, scoped_key: str
+    ) -> None:
+        """Pins GitHub issue #36086: a file upload through the dedicated prefix
+        reaches OpenAI's file API instead of 500ing on a provider-name lookup."""
+        content = f'{{"marker":"{unique_marker()}"}}\n'.encode()
+        uploaded = unwrap(
+            client.openai_passthrough_upload_file(
+                scoped_key, content=content, filename="e2e-passthrough-batch.jsonl"
+            )
+        )
+        resources.defer(
+            lambda: client.openai_passthrough_delete_file(scoped_key, uploaded.id)
+        )
+
+        assert uploaded.object == "file", (
+            f"/openai_passthrough/v1/files did not relay OpenAI's file object: {uploaded}"
+        )
+        assert uploaded.purpose == "batch"
+        assert uploaded.bytes == len(content)
+
+    @pytest.mark.covers("llm.batches.openai.passthrough.nonstream.works")
+    def test_passthrough_prefix_lists_batches_from_openai(
+        self, client: PassthroughClient, scoped_key: str
+    ) -> None:
+        """Pins GitHub issue #36086 on the batches route: the dedicated prefix
+        relays OpenAI's own batch page instead of dying on the provider lookup."""
+        listed = unwrap(client.openai_passthrough_list_batches(scoped_key))
+
+        assert listed.object == "list", (
+            f"/openai_passthrough/v1/batches did not relay OpenAI's batch page: {listed}"
+        )
+
+
+class TestOpenAIPassthroughSpend:
+    """A call relayed to OpenAI's own endpoints must still be costed.
+
+    The customer routes native OpenAI traffic through `/openai_passthrough` and
+    budgets against it, so a call that returns 200 while logging no spend is money
+    the gateway never sees and a budget that never trips. Streamed Responses calls
+    and embeddings each used to land exactly that way, on separate code paths.
+    """
+
+    @pytest.mark.covers("llm.responses.openai.passthrough.stream.cost_logged")
+    def test_streamed_responses_call_logs_its_cost(
+        self, client: PassthroughClient, scoped_key: str
+    ) -> None:
+        """Pins GitHub issue #36523: a streamed passthrough Responses call is billed
+        under the provider id the caller was served, never a $0 row under a random
+        id."""
+        result = client.openai_passthrough_responses(
+            scoped_key,
+            CHEAP_OPENAI_MODEL,
+            f"Say hi in one word. {unique_marker()}",
+            stream=True,
+        )
+        require_successful_call(result)
+        assert result.chunks > 0, "streamed responses passthrough produced no events"
+
+        completed = completed_responses_object(result)
+        assert completed is not None, (
+            f"the stream never delivered a response.completed frame, so there is no "
+            f"provider id to reconcile against: last events {result.stream_events[-3:]}"
+        )
+        assert completed.usage is not None, (
+            f"the completed response carried no usage to price from: {completed}"
+        )
+
+        rows = client.proxy.poll_logs_for_request_id(
+            completed.id, predicate=lambda rows: (rows[0].spend or 0) > 0
+        )
+        assert rows, (
+            f"no spend row for the response the customer was served ({completed.id}); "
+            "a streamed passthrough call OpenAI bills them for is invisible to the "
+            "gateway's own spend and budgets"
+        )
+        row = rows[0]
+        assert (row.spend or 0) > 0, f"streamed responses passthrough was not costed: {row}"
+        assert row.prompt_tokens == completed.usage.input_tokens, (
+            f"logged {row.prompt_tokens} prompt tokens, the response the customer read "
+            f"reported {completed.usage.input_tokens}"
+        )
+        assert row.completion_tokens == completed.usage.output_tokens, (
+            f"logged {row.completion_tokens} completion tokens, the response the customer "
+            f"read reported {completed.usage.output_tokens}"
+        )
+
+    @pytest.mark.covers("llm.embeddings.openai.passthrough.nonstream.cost_logged")
+    def test_embeddings_call_logs_its_cost(
+        self, client: PassthroughClient, scoped_key: str
+    ) -> None:
+        """Pins GitHub issue #36646: a passthrough embeddings call writes a priced
+        spend row instead of no row at all."""
+        result = client.openai_passthrough_embed(
+            scoped_key, EMBEDDING_MODEL, f"cost this sentence {unique_marker()}"
+        )
+        require_successful_call(result)
+        assert result.call_id, "embeddings passthrough returned no x-litellm-call-id"
+
+        rows = client.proxy.poll_logs_for_request_id(
+            result.call_id, predicate=lambda rows: (rows[0].spend or 0) > 0
+        )
+        assert rows, (
+            f"no spend row for embeddings call {result.call_id}; the customer is billed "
+            "by OpenAI for tokens the gateway never counted against their budget"
+        )
+        row = rows[0]
+        assert (row.spend or 0) > 0, f"embeddings passthrough was not costed: {row}"
+        assert (row.prompt_tokens or 0) > 0, (
+            f"the embeddings row logged no prompt tokens, so whatever cost it carries "
+            f"was not computed from the real usage: {row}"
+        )