diff --git a/tests/test_litellm/managed_agents/test_events.py b/tests/test_litellm/managed_agents/test_events.py
new file mode 100644
index 00000000000..a6103ef0aba
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+++ b/tests/test_litellm/managed_agents/test_events.py
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+"""Unit tests for `GET /v2/sessions/:id/events` (LIT-2920).
+
+Covers contract §6.6 + §7:
+- SSE stream format (one frame per event, blank line separator).
+- Required SSE headers (`Cache-Control: no-cache`, `Connection: keep-alive`,
+  `X-Accel-Buffering: no`, `Content-Type: text/event-stream`).
+- Pre-forward checks happen before streaming begins:
+    - 404 when the session does not exist for this caller.
+    - 503 when the session is still provisioning.
+    - 404 when the session is in a terminal state (terminated/error).
+- Mid-stream `SandboxUnreachableError` is converted to an inline `error`
+  SSE event (status code is already 200 by then).
+
+The handler depends on:
+- `user_api_key_auth` (FastAPI dep) — overridden via `app.dependency_overrides`.
+- `litellm.proxy.proxy_server.prisma_client` — patched to a sentinel.
+- `litellm.managed_agents.endpoints.events.get_session` — patched per test.
+- `litellm.managed_agents.endpoints.events.get_adapter` — patched per test.
+"""
+
+from typing import Any, AsyncIterator, Dict, List, Optional, Tuple
+from unittest.mock import patch
+
+import pytest
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+from litellm.managed_agents.adapters.base import SandboxUnreachableError
+from litellm.managed_agents.endpoints.events import router as events_router
+from litellm.proxy._types import UserAPIKeyAuth
+from litellm.proxy.auth.user_api_key_auth import user_api_key_auth
+
+
+# ---------------------------------------------------------------------------
+# Fixtures / helpers
+# ---------------------------------------------------------------------------
+
+
+CALLER_USER_ID = "user_xyz"
+
+
+def _build_app() -> FastAPI:
+    """Build a FastAPI app with the events router and auth override."""
+    app = FastAPI()
+    app.include_router(events_router)
+
+    async def _fake_auth() -> UserAPIKeyAuth:
+        return UserAPIKeyAuth(user_id=CALLER_USER_ID, api_key="sk-test")
+
+    app.dependency_overrides[user_api_key_auth] = _fake_auth
+    return app
+
+
+def _ready_session_row(
+    session_id: str = "ses_test",
+    sandbox_url: str = "http://127.0.0.1:1234",
+    oc_sid: str = "oc_sid_abc",
+) -> Dict[str, Any]:
+    return {
+        "id": session_id,
+        "agent_id": "agt_abc",
+        "sandbox_type": "opencode",
+        "sandbox_url": sandbox_url,
+        "sandbox_metadata": {"opencode_session_id": oc_sid},
+        "status": "ready",
+        "created_by": CALLER_USER_ID,
+    }
+
+
+class _FakeAdapter:
+    """Adapter stub matching the SandboxAdapter Protocol's stream_events.
+
+    Yields the supplied list of (event_type, data) tuples in order. If
+    `raise_after` is set, raises SandboxUnreachableError after that many
+    events have been yielded — used to test mid-stream error handling.
+    """
+
+    def __init__(
+        self,
+        events: List[Tuple[str, Dict[str, Any]]],
+        raise_after: Optional[int] = None,
+    ) -> None:
+        self.events = events
+        self.raise_after = raise_after
+
+    async def stream_events(
+        self,
+        sandbox_url: str,
+        opencode_session_id: str,
+        our_session_id: str,
+    ) -> AsyncIterator[Tuple[str, Dict[str, Any]]]:
+        for i, evt in enumerate(self.events):
+            if self.raise_after is not None and i >= self.raise_after:
+                raise SandboxUnreachableError("upstream is gone")
+            yield evt
+        if self.raise_after is not None and self.raise_after >= len(self.events):
+            raise SandboxUnreachableError("upstream is gone")
+
+
+# ---------------------------------------------------------------------------
+# Happy path — SSE format + headers
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_happy_path_format_and_headers() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    fake_adapter = _FakeAdapter(
+        events=[
+            ("connected", {"session_id": "ses_test"}),
+            (
+                "message.started",
+                {"message_id": "msg_a", "role": "assistant"},
+            ),
+            (
+                "message.completed",
+                {
+                    "message_id": "msg_a",
+                    "content": "hi",
+                    "completed_at": "2026-05-07T15:04:05.123Z",
+                },
+            ),
+        ]
+    )
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        assert session_id == "ses_test"
+        assert created_by == CALLER_USER_ID
+        return _ready_session_row()
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch(
+            "litellm.managed_agents.endpoints.events.get_adapter",
+            return_value=fake_adapter,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        with client.stream("GET", "/v2/sessions/ses_test/events") as r:
+            assert r.status_code == 200
+            # Headers per contract §6.6.
+            assert r.headers["content-type"].startswith("text/event-stream")
+            assert r.headers["cache-control"] == "no-cache"
+            assert r.headers["connection"] == "keep-alive"
+            assert r.headers["x-accel-buffering"] == "no"
+            body = b"".join(r.iter_bytes()).decode()
+
+    # First event must be `connected` per contract.
+    assert body.startswith('event: connected\ndata: {"session_id": "ses_test"}\n\n')
+    # Each event in order, separated by blank line.
+    assert (
+        "event: message.started\n"
+        'data: {"message_id": "msg_a", "role": "assistant"}\n\n'
+    ) in body
+    assert "event: message.completed\n" in body
+    assert body.endswith("\n\n")
+
+
+# ---------------------------------------------------------------------------
+# 404 — session missing (status code returned BEFORE streaming starts)
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_404_when_session_missing() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return None
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        r = client.get("/v2/sessions/ses_missing/events")
+
+    assert r.status_code == 404
+    assert "ses_missing" in r.json()["detail"]
+    assert r.headers["content-type"].startswith("application/json")
+
+
+# ---------------------------------------------------------------------------
+# 503 — session is still provisioning (status code BEFORE streaming starts)
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_503_when_session_provisioning() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    provisioning_row = _ready_session_row()
+    provisioning_row["status"] = "provisioning"
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return provisioning_row
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        r = client.get("/v2/sessions/ses_test/events")
+
+    assert r.status_code == 503
+    assert r.json()["detail"] == "Session not ready"
+    # Retry-After hint per contract §7 failure modes table.
+    assert r.headers.get("retry-after") == "5"
+
+
+# ---------------------------------------------------------------------------
+# 404 — terminated session is treated as not-found (per contract §7)
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_404_when_session_terminated() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    terminated_row = _ready_session_row()
+    terminated_row["status"] = "terminated"
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return terminated_row
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        r = client.get("/v2/sessions/ses_test/events")
+
+    assert r.status_code == 404
+
+
+# ---------------------------------------------------------------------------
+# Mid-stream SandboxUnreachableError → inline `error` event (status is 200)
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_unreachable_after_stream_started_emits_error_event() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    fake_adapter = _FakeAdapter(
+        events=[
+            ("connected", {"session_id": "ses_test"}),
+            ("message.started", {"message_id": "msg_a", "role": "assistant"}),
+        ],
+        raise_after=2,  # raise immediately after both events stream.
+    )
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return _ready_session_row()
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch(
+            "litellm.managed_agents.endpoints.events.get_adapter",
+            return_value=fake_adapter,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        with client.stream("GET", "/v2/sessions/ses_test/events") as r:
+            # Status was already 200 by the time the adapter raised.
+            assert r.status_code == 200
+            body = b"".join(r.iter_bytes()).decode()
+
+    assert "event: connected\n" in body
+    assert "event: message.started\n" in body
+    # Error becomes an inline SSE event with the canonical message.
+    assert 'event: error\ndata: {"error": "Sandbox unreachable"}\n\n' in body
+
+
+# ---------------------------------------------------------------------------
+# Pre-stream SandboxUnreachableError → still 200 with error event
+# (the adapter raises on the very first iteration, before any events stream).
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_unreachable_on_first_iteration_emits_error_only() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    # raise_after=0 means: raise before yielding anything.
+    fake_adapter = _FakeAdapter(events=[], raise_after=0)
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return _ready_session_row()
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch(
+            "litellm.managed_agents.endpoints.events.get_adapter",
+            return_value=fake_adapter,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        with client.stream("GET", "/v2/sessions/ses_test/events") as r:
+            # StreamingResponse always returns 200 once it's been constructed —
+            # the streaming generator hasn't run yet at that point.
+            assert r.status_code == 200
+            body = b"".join(r.iter_bytes()).decode()
+
+    assert body == 'event: error\ndata: {"error": "Sandbox unreachable"}\n\n'
+
+
+# ---------------------------------------------------------------------------
+# 500 — corrupt session row (missing sandbox state)
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_500_when_session_row_missing_sandbox_state() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    bad_row = _ready_session_row()
+    bad_row["sandbox_url"] = None  # corrupt: ready session must have a url.
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return bad_row
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        r = client.get("/v2/sessions/ses_test/events")
+
+    assert r.status_code == 500
+
+
+# ---------------------------------------------------------------------------
+# JSON-string sandbox_metadata is parsed defensively
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_handles_json_string_sandbox_metadata() -> None:
+    """Some Prisma clients return JSON columns as strings — handle that."""
+    app = _build_app()
+    client = TestClient(app)
+
+    row = _ready_session_row()
+    row["sandbox_metadata"] = '{"opencode_session_id": "oc_sid_abc"}'
+
+    fake_adapter = _FakeAdapter(events=[("connected", {"session_id": "ses_test"})])
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        return row
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch(
+            "litellm.managed_agents.endpoints.events.get_adapter",
+            return_value=fake_adapter,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        with client.stream("GET", "/v2/sessions/ses_test/events") as r:
+            assert r.status_code == 200
+            body = b"".join(r.iter_bytes()).decode()
+
+    assert "event: connected\n" in body
+
+
+# ---------------------------------------------------------------------------
+# 500 — prisma client not initialized
+# ---------------------------------------------------------------------------
+
+
+def test_stream_events_500_when_prisma_client_not_initialized() -> None:
+    app = _build_app()
+    client = TestClient(app)
+
+    with patch("litellm.proxy.proxy_server.prisma_client", None):
+        r = client.get("/v2/sessions/ses_test/events")
+
+    assert r.status_code == 500
+
+
+# ---------------------------------------------------------------------------
+# Caller scoping is enforced — _load_ready_session passes user_id through.
+# ---------------------------------------------------------------------------
+
+
+@pytest.mark.asyncio
+async def test_stream_events_scopes_by_caller_user_id() -> None:
+    """The handler must pass `user_api_key_dict.user_id` as `created_by`.
+
+    Without scoping, callers could read other users' sessions.
+    """
+    app = _build_app()
+    client = TestClient(app)
+
+    captured: Dict[str, Any] = {}
+
+    async def _fake_get_session(prisma_client, *, session_id, created_by):
+        captured["session_id"] = session_id
+        captured["created_by"] = created_by
+        return None  # 404 — but we only care that scoping was used.
+
+    with (
+        patch(
+            "litellm.managed_agents.endpoints.events.get_session",
+            side_effect=_fake_get_session,
+        ),
+        patch("litellm.proxy.proxy_server.prisma_client", object()),
+    ):
+        r = client.get("/v2/sessions/ses_test/events")
+
+    assert r.status_code == 404
+    assert captured["session_id"] == "ses_test"
+    assert captured["created_by"] == CALLER_USER_ID