fix(proxy): exit when DATABASE_URL is set but the Prisma toolchain is missing (#44207)

With DATABASE_URL set and no way to run the Prisma CLI (not on PATH, not importable), run_server used to print a plain notice and keep booting. The server then crashed later inside the DB exception handler with an unrelated ModuleNotFoundError traceback, and the migration-only entrypoint (--skip_server_startup) exited 0 without migrating. It now exits 1 with a red one-line message naming the missing toolchain and how to install it. The no-DATABASE_URL path is unchanged.

Co-authored-by: yassin <yassin@berri.ai>
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/proxy_cli.py

@@ -1447,9 +1447,11 @@ def run_server(
                         sys.exit(1)
             else:
                 print(
-                    "Unable to connect to DB. DATABASE_URL found in environment, but the prisma CLI is neither on "
-                    "PATH nor importable as a package."
+                    "\033[1;31mLiteLLM Proxy: a database URL is set but the prisma CLI is neither on PATH nor importable "
+                    "as a package, so the database cannot be set up. Install it with `pip install 'litellm[extra_proxy]'` "
+                    "or run a shipped LiteLLM image.\033[0m"
                 )
+                sys.exit(1)
         pgbouncer_settings: Final = PgBouncerSettings()
         upstream_database_url: Final = os.getenv("DATABASE_URL")
         if pgbouncer_settings.enabled and upstream_database_url is not None:

tests/unit/proxy/test_proxy_cli.py

@@ -2265,6 +2265,63 @@ class TestRunServerDbSetup:
         assert "prisma CLI is neither on PATH" not in capsys.readouterr().out
         mock_setup_database.assert_called_once_with(use_migrate=True, use_v2_resolver=True)
 
+    @pytest.mark.parametrize(
+        ("database_url", "exits"),
+        (("postgresql://test:test@localhost:5432/test", True), (None, False)),
+        ids=("database-url-set", "no-database-url"),
+    )
+    @patch("atexit.register")
+    def test_startup_exits_when_the_prisma_toolchain_is_missing_only_if_a_database_is_configured(
+        self,
+        mock_atexit_register,
+        database_url,
+        exits,
+        tmp_path,
+        capsys,
+    ):
+        """A DATABASE_URL with no way to run the Prisma CLI is fatal; no DATABASE_URL needs no Prisma at all."""
+        from litellm_proxy_extras import prisma_toolchain
+
+        from litellm.proxy.proxy_cli import run_server
+
+        empty_bin = tmp_path / "emptybin"
+        empty_bin.mkdir()
+        real_find_spec = prisma_toolchain.importlib.util.find_spec
+
+        def hide_prisma(name, package=None):
+            return None if name == "prisma" else real_find_spec(name, package)
+
+        mock_proxy_module = MagicMock(
+            app=MagicMock(),
+            ProxyConfig=MagicMock(),
+            KeyManagementSettings=MagicMock(),
+            save_worker_config=MagicMock(),
+        )
+        clean_env = {k: v for k, v in os.environ.items() if k not in ("DATABASE_URL", "DIRECT_URL")}
+        clean_env["PATH"] = str(empty_bin)
+        if database_url is not None:
+            clean_env["DATABASE_URL"] = database_url
+
+        with (
+            patch.dict(os.environ, clean_env, clear=True),
+            patch.dict(
+                "sys.modules",
+                {"proxy_server": mock_proxy_module, "litellm.proxy.proxy_server": mock_proxy_module},
+            ),
+            patch.object(prisma_toolchain.importlib.util, "find_spec", side_effect=hide_prisma),
+            pytest.raises(SystemExit) if exits else nullcontext() as exit_info,
+        ):
+            run_server.main(["--local", "--skip_server_startup"], standalone_mode=False)
+
+        out = capsys.readouterr().out
+        if exits:
+            assert exit_info.value.code == 1
+            assert "a database URL is set but the prisma CLI is neither on PATH nor importable" in out
+            assert "pip install 'litellm[extra_proxy]'" in out
+        else:
+            assert "prisma CLI" not in out
+            assert "Setup complete" in out
+
     @patch("subprocess.run")
     @patch("atexit.register")
     @patch("litellm.proxy.db.prisma_client.PrismaManager.setup_database")