fix(proxy): print startup messages once and without color codes off a terminal

litellm/_logging.py

@@ -598,6 +598,7 @@ _LOG_FORMAT_PREFIX: Final = "%(asctime)s - %(name)s:%(levelname)s"
 _LOG_FORMAT_SUFFIX: Final = ": %(filename)s:%(lineno)s - %(message)s"
 _PLAIN_LOG_FORMAT: Final = _LOG_FORMAT_PREFIX + _LOG_FORMAT_SUFFIX
 _COLOR_LOG_FORMAT: Final = f"\033[92m{_LOG_FORMAT_PREFIX}\033[0m{_LOG_FORMAT_SUFFIX}"
+_ANSI_ESCAPE: Final = re.compile(r"\x1b\[[0-9;]*m")
 
 
 def _stream_is_tty(stream: TextIO | None) -> bool:
@@ -612,15 +613,18 @@ def _stream_is_tty(stream: TextIO | None) -> bool:
         return False
 
 
-def _plain_log_format(stdout: TextIO | None, stderr: TextIO | None) -> str:
-    """The plain-text log format, colorized only when both streams are an interactive terminal.
+def _color_enabled(stream: TextIO | None) -> bool:
+    """True when ANSI colors written to the stream reach an interactive terminal.
 
     Honors the NO_COLOR convention from no-color.org: color is disabled when
     NO_COLOR is present with a non-empty value.
     """
-    if os.environ.get("NO_COLOR"):
-        return _PLAIN_LOG_FORMAT
-    return _COLOR_LOG_FORMAT if _stream_is_tty(stdout) and _stream_is_tty(stderr) else _PLAIN_LOG_FORMAT
+    return not os.environ.get("NO_COLOR") and _stream_is_tty(stream)
+
+
+def _plain_log_format(stdout: TextIO | None, stderr: TextIO | None) -> str:
+    """The plain-text log format, colorized only when both streams are an interactive terminal."""
+    return _COLOR_LOG_FORMAT if _color_enabled(stdout) and _color_enabled(stderr) else _PLAIN_LOG_FORMAT
 
 
 class LevelRoutingStreamHandler(logging.StreamHandler):
@@ -744,7 +748,7 @@ class JsonFormatter(Formatter):
         return dt.isoformat()
 
     def format(self, record):
-        message_str: Final = record.getMessage()
+        message_str: Final = _ANSI_ESCAPE.sub("", record.getMessage())
         json_record: Final[dict[str, object]] = {
             "message": message_str,
             "level": record.levelname,
@@ -800,12 +804,14 @@ class CorrelationPlainFormatter(logging.Formatter):
     """Appends trace_id/session_id to plain-text log lines stamped by CorrelationContextFilter.
 
     Mirrors JsonFormatter's handling of these two fields so request_correlation_in_logs
-    behaves the same whether or not json_logs is enabled.
+    behaves the same whether or not json_logs is enabled. Unless it was built with the color format,
+    it also drops the ANSI color codes a message carries, which a piped log would store as text.
     """
 
     def format(self, record: logging.LogRecord) -> str:
         rendered: Final = super().format(record)
-        formatted: Final = rendered if _is_redacted(record) else redact_string(rendered)
+        uncolored: Final = rendered if self._fmt == _COLOR_LOG_FORMAT else _ANSI_ESCAPE.sub("", rendered)
+        formatted: Final = uncolored if _is_redacted(record) else redact_string(uncolored)
         trace_id: Final = getattr(record, "trace_id", None)
         session_id: Final = getattr(record, "session_id", None)
         if not trace_id and not session_id:
@@ -899,23 +905,23 @@ verbose_proxy_logger.addFilter(_diagnostic_filter)
 verbose_proxy_stdout_logger.addFilter(_diagnostic_filter)
 verbose_logger.addFilter(_diagnostic_filter)
 
-_ANSI_ESCAPE: Final = re.compile(r"\x1b\[[0-9;]*m")
-
 
 def print_startup_message(message: str) -> None:
     """Write a boot-time message meant for the operator's terminal.
 
     LITELLM_SUPPRESS_STARTUP_OUTPUT or litellm_settings.suppress_startup_output turns every one of them
-    off. Plain mode prints it unchanged, colors and spacing included, and flushes it so a piped stdout
-    shows it at once. With JSON logs on, every line of stdout is read by a log pipeline, so the message
-    goes out as one INFO record of the proxy logger instead, on stdout like the print whatever handlers
-    the logging config gave that logger, with the ANSI color codes and surrounding blank lines removed,
-    located at the caller and emitted at any log level; a blank spacer produces no record.
+    off. Plain mode prints it with its spacing, keeping the ANSI colors only when stdout is a color
+    terminal by the same check as the plain log format, so a container log never stores escape codes.
+    With JSON logs on, every line of stdout is read by a log pipeline, so the message goes out as one
+    INFO record of the proxy logger instead, on stdout like the print whatever handlers the logging
+    config gave that logger, with the ANSI color codes and surrounding blank lines removed, located at
+    the caller and emitted at any log level; a blank spacer produces no record.
     """
     if litellm.suppress_startup_output is True:
         return
     if not litellm.json_logs:
-        print(message, flush=True)  # noqa: T201  # plain mode: this is the operator-terminal print it replaces
+        printed: Final = message if _color_enabled(sys.stdout) else _ANSI_ESCAPE.sub("", message)
+        print(printed, flush=True)  # noqa: T201  # plain mode: this is the operator-terminal print it replaces
         return
     text: Final = _ANSI_ESCAPE.sub("", message).strip("\n")
     if not text:

litellm/proxy/proxy_server.py

@@ -6378,13 +6378,8 @@ class ProxyConfig:
 
         search_tools_parsed: Final[list[SearchToolTypedDict]] = []
 
-        print_startup_message("\033[32mLiteLLM: Proxy initialized with Search Tools:\033[0m")
-
         for search_tool in search_tools_raw:
-            # Display loaded search tool
             search_tool_name = search_tool.get("search_tool_name", "")
-            search_provider = search_tool.get("litellm_params", {}).get("search_provider", "")
-            print_startup_message(f"\033[32m    {search_tool_name} ({search_provider})\033[0m")
 
             # Handle os.environ/ variables in litellm_params
             litellm_params = search_tool.get("litellm_params", {})
@@ -6560,7 +6555,7 @@ class ProxyConfig:
             reset_color_code: Final = "\033[0m"
             for key, value in litellm_settings.items():
                 if key == "cache" and value is True:
-                    print_startup_message(f"{blue_color_code}\nSetting Cache on Proxy")
+                    print_startup_message(f"\n{blue_color_code}Setting Cache on Proxy{reset_color_code}")
                     from litellm.caching.caching import Cache
 
                     cache_params = {}
@@ -7230,6 +7225,19 @@ class ProxyConfig:
 
         ## SEARCH TOOLS SETTINGS
         search_tools: Final[list[SearchToolTypedDict] | None] = self.parse_search_tools(config)
+        if search_tools:
+            print_startup_message(
+                "\n".join(
+                    (
+                        "\033[32mLiteLLM: Proxy initialized with Search Tools:\033[0m",
+                        *(
+                            f"\033[32m    {tool.get('search_tool_name', '')} "
+                            f"({tool.get('litellm_params', {}).get('search_provider', '')})\033[0m"
+                            for tool in search_tools
+                        ),
+                    )
+                )
+            )
 
         ## SANDBOX TOOLS SETTINGS
         from litellm.sandbox.sandbox_tools import register_sandbox_tools

tests/integration/configuration/test_startup_output.py

@@ -2,9 +2,10 @@
 
 A container runtime reads the proxy's stdout through a pipe and keeps every line. This contract boots an owned
 proxy with a search tool configured and a one-second config reload interval, serves a chat request, lets the
-search tools reload job run several times and reads everything the proxy wrote. With
-LITELLM_SUPPRESS_STARTUP_OUTPUT or litellm_settings.suppress_startup_output on, none of the startup messages
-arrive, in plain and JSON mode alike.
+search tools reload job run several times and reads everything the proxy wrote. With the setting off, every
+startup message arrives, the search tools listing once per worker however many reloads ran, and no line
+carries an ANSI color code, since the output is a pipe and not a terminal. With LITELLM_SUPPRESS_STARTUP_OUTPUT
+or litellm_settings.suppress_startup_output on, none of them arrive, in plain and JSON mode alike.
 """
 
 from __future__ import annotations
@@ -34,6 +35,8 @@ STARTUP_MESSAGES: Final = (
     SEARCH_TOOLS_HEADER,
     "Postgres connection budget",
 )
+ANSI_ESCAPE: Final = "\x1b["
+WORKER_COUNTS: Final = (1, 2)
 CACHE_SETTINGS: Final[Mapping[str, JsonValue]] = {"cache": True, "cache_params": {"type": "redis"}}
 
 
@@ -108,6 +111,20 @@ def _boot_reload_and_stop(
     return log.read_text(), search_tool
 
 
+@pytest.mark.parametrize("workers", WORKER_COUNTS)
+def test_startup_messages_reach_a_piped_stdout_once_and_without_color_codes(
+    gateway: Gateway, tmp_path: Path, workers: int
+) -> None:
+    log, search_tool = _boot_reload_and_stop(gateway, tmp_path, CACHE_SETTINGS, {}, workers)
+
+    for message in STARTUP_MESSAGES:
+        assert message in log, (message, log)
+    assert _lines_with(log, SEARCH_TOOLS_HEADER) == workers, log
+    assert _lines_with(log, f"{search_tool} (tavily)") == workers, log
+    colored: Final = tuple(line for line in log.splitlines() if ANSI_ESCAPE in line)
+    assert colored == (), "lines with ANSI color codes on a piped stdout:\n" + "\n".join(colored)
+
+
 @pytest.mark.parametrize(
     ("litellm_settings", "overrides"),
     [

tests/unit/proxy/proxy_server/test_proxy_config.py

@@ -2088,6 +2088,36 @@ def test_ProxyConfig_parse_search_tools_missing_returns_none():
     assert pc.parse_search_tools({}) is None
 
 
+@pytest.mark.asyncio
+async def test_ProxyConfig_lists_search_tools_once_at_startup_not_on_every_reparse(
+    tmp_path: Path, monkeypatch: pytest.MonkeyPatch, capfd: pytest.CaptureFixture[str]
+):
+    """The search tools reload job and add_deployment re-parse search_tools every config reload interval, so
+    the startup listing belongs to load_config alone, or a container log repeats it every 30 seconds."""
+    config_file: Final = tmp_path / "search.yaml"
+    config_file.write_text(
+        "model_list: []\n"
+        "search_tools:\n"
+        "  - search_tool_name: web-search\n"
+        "    litellm_params:\n"
+        "      search_provider: tavily\n"
+    )
+    monkeypatch.setattr(litellm, "json_logs", False)
+    monkeypatch.setattr(litellm, "suppress_startup_output", False)
+    monkeypatch.setattr("litellm.proxy.proxy_server.prisma_client", None)
+    monkeypatch.setattr("litellm.proxy.proxy_server.store_model_in_db", False)
+    monkeypatch.delenv("LITELLM_CONFIG_BUCKET_NAME", raising=False)
+    proxy_config: Final = ProxyConfig()
+
+    await proxy_config.load_config(router=None, config_file_path=str(config_file))
+    for _ in range(3):
+        assert proxy_config.parse_search_tools(proxy_config.get_config_state()) is not None
+
+    out: Final = capfd.readouterr().out
+    assert out.count("Proxy initialized with Search Tools:") == 1, out
+    assert out.count("web-search (tavily)") == 1, out
+
+
 def test_ProxyConfig_merge_config_and_db_search_tools_returns_superset():
     config_tools = [
         {

tests/unit/test_logging.py

@@ -1408,6 +1408,32 @@ def test_plain_log_format_survives_hostile_streams(stdout, stderr):
     assert _plain_log_format(stdout, stderr) == _PLAIN_LOG_FORMAT
 
 
+def _router_success_record() -> logging.LogRecord:
+    return logging.LogRecord(
+        "LiteLLM Router", logging.INFO, "router.py", 1, "litellm.acompletion(model=%s)\033[32m 200 OK\033[0m", ("gpt-5.6",), None
+    )
+
+
+@pytest.mark.parametrize(
+    ("log_format", "want_suffix"),
+    [
+        (_COLOR_LOG_FORMAT, "litellm.acompletion(model=gpt-5.6)\033[32m 200 OK\033[0m"),
+        (_PLAIN_LOG_FORMAT, "router.py:1 - litellm.acompletion(model=gpt-5.6) 200 OK"),
+    ],
+)
+def test_plain_formatter_keeps_message_colors_only_with_the_color_format(log_format: str, want_suffix: str):
+    """A message that embeds color codes keeps them on a color terminal. Piped, or under NO_COLOR, the plain
+    format is chosen and the codes go too, so a container log never stores them as text."""
+    assert CorrelationPlainFormatter(log_format).format(_router_success_record()).endswith(want_suffix)
+
+
+def test_json_formatter_drops_color_codes_from_the_message():
+    """A JSON log line is read by a log pipeline, never a terminal, so a colored message arrives as plain text."""
+    assert json.loads(JsonFormatter().format(_router_success_record()))["message"] == (
+        "litellm.acompletion(model=gpt-5.6) 200 OK"
+    )
+
+
 def test_level_routing_handler_falls_back_to_stderr_when_stdout_is_unusable(monkeypatch, capsys):
     logger = logging.getLogger("test_level_routing_fallback")
     logger.handlers.clear()
@@ -1827,15 +1853,39 @@ def test_print_verbose_formats_args_only_when_set_verbose_is_on(monkeypatch, cap
     assert capsys.readouterr().out == "key k1 value cached-vector\n"
 
 
-def test_print_startup_message_prints_plain_mode_text_unchanged(monkeypatch, capfd):
-    """Operators without JSON logs keep the colored, spaced terminal output exactly as before."""
+class _CapturedStream(StringIO):
+    def __init__(self, tty: bool) -> None:
+        super().__init__()
+        self._tty = tty
+
+    def isatty(self) -> bool:
+        return self._tty
+
+
+@pytest.mark.parametrize(
+    "stdout_tty, no_color, want_color",
+    [(True, None, True), (False, None, False), (True, "1", False)],
+)
+def test_print_startup_message_keeps_colors_only_on_a_color_terminal(
+    monkeypatch: pytest.MonkeyPatch, stdout_tty: bool, no_color: str | None, want_color: bool
+):
+    """Operators without JSON logs keep the colored, spaced output on a terminal. A container runtime reads
+    stdout through a pipe and stores the escape codes as text, so there, and under NO_COLOR, the colors go."""
     monkeypatch.setattr(litellm, "json_logs", False)
+    if no_color is None:
+        monkeypatch.delenv("NO_COLOR", raising=False)
+    else:
+        monkeypatch.setenv("NO_COLOR", no_color)
+    stdout: Final = _CapturedStream(stdout_tty)
+    monkeypatch.setattr(sys, "stdout", stdout)
 
     print_startup_message("\n\033[1;32mLiteLLM: Proxy initialized with Config, Set models:\033[0m\n")
 
-    out, err = capfd.readouterr()
-    assert out == "\n\033[1;32mLiteLLM: Proxy initialized with Config, Set models:\033[0m\n\n"
-    assert err == ""
+    assert stdout.getvalue() == (
+        "\n\033[1;32mLiteLLM: Proxy initialized with Config, Set models:\033[0m\n\n"
+        if want_color
+        else "\nLiteLLM: Proxy initialized with Config, Set models:\n\n"
+    )
 
 
 @pytest.mark.parametrize("json_logs", [False, True])