diff --git a/tests/proxy_behavior/management/conftest.py b/tests/proxy_behavior/management/conftest.py
index c16adc39db1..23f2e24e604 100644
--- a/tests/proxy_behavior/management/conftest.py
+++ b/tests/proxy_behavior/management/conftest.py
@@ -7,6 +7,8 @@ run. Tests assert at the HTTP boundary.
 
 import os
 import tempfile
+import uuid
+from dataclasses import dataclass
 from typing import AsyncIterator
 
 import httpx
@@ -80,9 +82,66 @@ async def world(prisma):
     """The immutable read-world seed.
 
     Re-seeds at session start so each pytest invocation gets a clean world.
-    Tests must not mutate these rows; write tests use Slice 5's namespace +
-    teardown fixtures for scratch entities.
+    Tests must not mutate these rows; write tests use the ``scratch`` fixture
+    below for scoped entities that get torn down per-test.
     """
     from .actors import seed_world
 
     return await seed_world(prisma)
+
+
+SCRATCH_PREFIX = "scratch-"
+
+
+@dataclass(frozen=True)
+class Scratch:
+    """Per-test namespace for write scenarios.
+
+    Tests must tag any entity they create with ``scratch.prefix`` in a column
+    the teardown filter inspects (``key_alias``, ``key_name``, ``team_alias``,
+    ``team_id``, ``user_id``, or ``budget_id``). Anything not tagged will be
+    left behind and pollute the next session.
+    """
+
+    prefix: str
+
+    def tag(self, suffix: str = "") -> str:
+        return f"{self.prefix}-{suffix}" if suffix else self.prefix
+
+
+@pytest_asyncio.fixture
+async def scratch(prisma):
+    """Function-scoped scratch namespace + targeted delete_many teardown.
+
+    The teardown deletes any rows on the volatile tables whose namespace column
+    starts with ``scratch.prefix``. Per CLAUDE.md, this is Prisma-only — no raw
+    SQL — and uses ``delete_many`` to batch the writes.
+    """
+    handle = Scratch(prefix=f"{SCRATCH_PREFIX}{uuid.uuid4().hex[:12]}")
+    try:
+        yield handle
+    finally:
+        # Order matters: children before parents to avoid FK conflicts.
+        await prisma.db.litellm_verificationtoken.delete_many(
+            where={
+                "OR": [
+                    {"key_alias": {"startswith": handle.prefix}},
+                    {"key_name": {"startswith": handle.prefix}},
+                ]
+            }
+        )
+        await prisma.db.litellm_teammembership.delete_many(
+            where={"team_id": {"startswith": handle.prefix}}
+        )
+        await prisma.db.litellm_organizationmembership.delete_many(
+            where={"user_id": {"startswith": handle.prefix}}
+        )
+        await prisma.db.litellm_teamtable.delete_many(
+            where={"team_id": {"startswith": handle.prefix}}
+        )
+        await prisma.db.litellm_usertable.delete_many(
+            where={"user_id": {"startswith": handle.prefix}}
+        )
+        await prisma.db.litellm_budgettable.delete_many(
+            where={"budget_id": {"startswith": handle.prefix}}
+        )
diff --git a/tests/proxy_behavior/management/test_scratch_teardown.py b/tests/proxy_behavior/management/test_scratch_teardown.py
new file mode 100644
index 00000000000..1f6bad64539
--- /dev/null
+++ b/tests/proxy_behavior/management/test_scratch_teardown.py
@@ -0,0 +1,41 @@
+"""Slice 5 smoke: scratch namespace fixture cleans up after itself.
+
+Two ordered tests. The first writes a key tagged with the scratch prefix and
+asserts it lands. The second runs after the first's teardown and asserts no
+scratch-namespaced rows survived. Together they prove the per-test cleanup
+filter is the right shape — any leaked row will surface as a test-2 failure on
+the very next run.
+"""
+
+import pytest
+
+from .conftest import MASTER_KEY, SCRATCH_PREFIX
+
+pytestmark = pytest.mark.asyncio(loop_scope="session")
+
+
+async def test_a_scratch_key_lands_in_db(proxy_client, prisma, scratch):
+    resp = await proxy_client.post(
+        "/key/generate",
+        headers={"Authorization": f"Bearer {MASTER_KEY}"},
+        json={"key_alias": scratch.prefix},
+    )
+    assert resp.status_code == 200, resp.text
+
+    rows = await prisma.db.litellm_verificationtoken.find_many(
+        where={"key_alias": scratch.prefix}
+    )
+    assert (
+        len(rows) == 1
+    ), f"expected exactly one scratch-tagged token, found {len(rows)}"
+
+
+async def test_b_scratch_namespace_is_clean(prisma):
+    """Runs after test_a's teardown — proves nothing leaked."""
+    rows = await prisma.db.litellm_verificationtoken.find_many(
+        where={"key_alias": {"startswith": SCRATCH_PREFIX}}
+    )
+    assert rows == [], (
+        f"scratch teardown leaked {len(rows)} rows; first key_alias: "
+        f"{rows[0].key_alias if rows else None!r}"
+    )
diff --git a/tests/proxy_behavior/management/test_smoke.py b/tests/proxy_behavior/management/test_smoke.py
index dbabd120d0a..5675a99606c 100644
--- a/tests/proxy_behavior/management/test_smoke.py
+++ b/tests/proxy_behavior/management/test_smoke.py
@@ -12,7 +12,7 @@ async def test_liveliness(proxy_client):
     assert resp.status_code == 200
 
 
-async def test_key_generate_lands_in_db(proxy_client):
+async def test_key_generate_lands_in_db(proxy_client, prisma, scratch):
     """De-risk gate: prove the harness exercises the full stack end-to-end.
 
     A successful ``/key/generate`` requires:
@@ -22,21 +22,16 @@ async def test_key_generate_lands_in_db(proxy_client):
       * the real ``generate_key_helper_fn`` wrote a hashed row to
         ``LiteLLM_VerificationToken``.
 
-    All four collapse to a single 200 + ``sk-`` token check here, with a
-    follow-up prisma read to prove the row landed (and that the token is the
-    hashed form, not the cleartext returned over the wire).
+    The scratch fixture tags the row with its prefix so the per-test teardown
+    cleans it up — keeps the proxy DB free of accumulated cruft on repeated
+    local runs.
     """
-    from litellm.proxy import proxy_server
     from litellm.proxy.utils import hash_token
 
-    assert (
-        proxy_server.prisma_client is not None
-    ), "FastAPI lifespan did not connect prisma — harness is wrong."
-
     resp = await proxy_client.post(
         "/key/generate",
         headers={"Authorization": f"Bearer {MASTER_KEY}"},
-        json={},
+        json={"key_alias": scratch.prefix},
     )
     assert resp.status_code == 200, resp.text
     body = resp.json()
@@ -44,9 +39,7 @@ async def test_key_generate_lands_in_db(proxy_client):
     assert cleartext_key.startswith("sk-")
 
     hashed = hash_token(cleartext_key)
-    row = await proxy_server.prisma_client.db.litellm_verificationtoken.find_unique(
-        where={"token": hashed}
-    )
+    row = await prisma.db.litellm_verificationtoken.find_unique(where={"token": hashed})
     assert row is not None, "Generated key did not land in LiteLLM_VerificationToken"
     assert row.token == hashed
     assert (