fix(proxy): keep show_banner() SDK-free, pick the JSON banner in initialize()

Since #46803 the `lite` shell calls show_banner() against an uninitialized
litellm package, and reading litellm.json_logs inside it initialized the whole
SDK at the banner (0.14 s to 0.83 s for a bare `lite` here, the seconds that PR
removed on small VMs). show_banner() is back to its main version; the proxy's
initialize() now emits the JSON banner record itself and calls show_banner()
only in plain mode. The banner unit tests move to the initialize() call site.

litellm/proxy/common_utils/banner.py

@@ -11,12 +11,6 @@ LITELLM_BANNER: Final = """   ██╗     ██╗████████╗
 
 def show_banner():
     """Display the LiteLLM CLI banner."""
-    import litellm
-    from litellm._logging import print_startup_message
-
-    if litellm.json_logs:
-        print_startup_message(LITELLM_BANNER)
-        return
     try:
         import click
 

litellm/proxy/proxy_server.py

@@ -9550,9 +9550,14 @@ async def initialize(
         master_key, \
         user_custom_auth, \
         prisma_client
-    from litellm.proxy.common_utils.banner import show_banner
+    from litellm.proxy.common_utils.banner import LITELLM_BANNER, show_banner
 
-    show_banner()
+    # show_banner() also serves the `lite` shell, which runs against an uninitialized SDK (#46803), so
+    # the JSON-mode choice stays out of it.
+    if litellm.json_logs:
+        print_startup_message(LITELLM_BANNER)
+    else:
+        show_banner()
     if os.getenv("LITELLM_DONT_SHOW_FEEDBACK_BOX", "").lower() != "true":
         generate_feedback_box()
     user_model = model

tests/unit/proxy/common_utils/test_banner.py

@@ -1,36 +0,0 @@
-"""The CLI banner is terminal art in plain mode and one JSON record when json_logs is on."""
-
-import json
-import sys
-from typing import Final
-
-import litellm
-from litellm._logging import turn_on_json
-from litellm.proxy.common_utils.banner import LITELLM_BANNER, show_banner
-
-
-def test_show_banner_prints_the_banner_between_blank_lines_in_plain_mode(monkeypatch, capfd):
-    """Operators without JSON logs see the banner exactly as before."""
-    monkeypatch.setattr(litellm, "json_logs", False)
-
-    show_banner()
-
-    assert capfd.readouterr() == (f"\n{LITELLM_BANNER}\n\n", "")
-
-
-def test_show_banner_is_one_json_record_in_json_mode(monkeypatch, capfd):
-    """With JSON logs on, the six banner rows are one INFO record with their indentation kept, so the
-    first line a worker writes parses like every other."""
-    monkeypatch.setattr(litellm, "json_logs", True)
-    monkeypatch.setattr(sys, "excepthook", sys.excepthook)  # turn_on_json swaps it; put it back at teardown
-    turn_on_json()
-
-    show_banner()
-
-    out, err = capfd.readouterr()
-    assert err == ""
-    lines: Final = [raw for raw in out.splitlines() if raw.strip()]
-    assert len(lines) == 1, lines
-    record: Final = json.loads(lines[0])
-    assert record["message"] == LITELLM_BANNER
-    assert record["level"] == "INFO"

tests/unit/proxy/test_proxy_server_endpoints_and_startup.py

@@ -48,6 +48,7 @@ from litellm.proxy.auth.user_api_key_auth import user_api_key_auth
 from litellm.proxy.hooks.parallel_request_limiter_v3 import RequestRateLimiterStash
 from litellm.proxy.proxy_server import app, aws_error_type_exception_handler, initialize, openai_exception_handler
 from litellm.utils import _invalidate_model_cost_lowercase_map
+from litellm.proxy.common_utils.banner import LITELLM_BANNER
 from tests._master_key import MASTER_KEY
 
 PUBLICLY_KNOWN_KEY: Final = "sk-" + "1234"
@@ -15725,3 +15726,36 @@ def test_feedback_box_is_one_json_record_in_json_mode(monkeypatch, capfd):
     assert "Give Feedback / Get Help: https://github.com/BerriAI/litellm/issues/new" in record["message"]
     assert "Thank you for using LiteLLM! - Krrish & Ishaan" in record["message"]
     assert "\x1b[" not in record["message"]
+
+
+@pytest.mark.asyncio
+async def test_initialize_prints_the_banner_between_blank_lines_in_plain_mode(monkeypatch, capfd):
+    """Operators without JSON logs see the banner exactly as before, through show_banner()'s flushing
+    click.echo."""
+    monkeypatch.setattr(litellm, "json_logs", False)
+    monkeypatch.setenv("LITELLM_DONT_SHOW_FEEDBACK_BOX", "true")
+
+    await proxy_server_module.initialize()
+
+    out, err = capfd.readouterr()
+    assert err == ""
+    assert out.startswith(f"\n{LITELLM_BANNER}\n\n"), out
+
+
+@pytest.mark.asyncio
+async def test_initialize_prints_the_banner_as_one_json_record_in_json_mode(monkeypatch, capfd):
+    """With JSON logs on, the six banner rows are one INFO record with their indentation kept, so the
+    first line a worker writes parses like every other."""
+    monkeypatch.setattr(litellm, "json_logs", True)
+    monkeypatch.setattr(sys, "excepthook", sys.excepthook)  # turn_on_json swaps it; put it back at teardown
+    monkeypatch.setenv("LITELLM_DONT_SHOW_FEEDBACK_BOX", "true")
+    turn_on_json()
+
+    await proxy_server_module.initialize()
+
+    out, err = capfd.readouterr()
+    assert err == ""
+    records: Final = [json.loads(raw) for raw in out.splitlines() if raw.strip()]
+    banner_records: Final = [record for record in records if record["message"] == LITELLM_BANNER]
+    assert len(banner_records) == 1, records
+    assert banner_records[0]["level"] == "INFO"