fix(images): forward max_retries to the OpenAI image generation handler

image_generation() keeps `max_retries` out of `non_default_params` (it is
in `openai_params`), and the OpenAI branch never passed it on, so
OpenAIChatCompletion.image_generation always fell back to
`data.pop("max_retries", 2)`. A caller's (or a Router's) max_retries was
ignored and every image request could make 3 upstream attempts. Forward
it in optional_params, where the handler already reads it; with nothing
set, the handler keeps its default.

Fixes #47431

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

litellm/images/main.py

@@ -491,6 +491,12 @@ def image_generation(
         ):
             if extra_headers is not None:
                 optional_params["extra_headers"] = extra_headers
+            # `max_retries` is kept out of `non_default_params` (it is in
+            # `openai_params`), so forward it explicitly: the handler reads it
+            # from `optional_params` and otherwise defaults to 2 retries.
+            max_retries: Final = kwargs.get("max_retries", None)
+            if max_retries is not None:
+                optional_params["max_retries"] = max_retries
             # Forward OpenAI organization if present (set by proxy pre-call utils)
             organization: Final[str | None] = kwargs.get("organization", None)
             model_response = openai_chat_completions.image_generation(

tests/unit/images/test_image_generation_max_retries.py

@@ -0,0 +1,77 @@
+"""`max_retries` passed to image_generation() reaches the OpenAI image handler.
+
+It used to be filtered out with the other OpenAI client params and never
+forwarded, so the handler always fell back to its default of 2 retries.
+"""
+
+from unittest.mock import patch
+
+import pytest
+
+import litellm
+from litellm.images.main import image_generation
+
+
+def _optional_params(mock_openai_chat_completions) -> dict:
+    call_kwargs = mock_openai_chat_completions.image_generation.call_args
+    return call_kwargs.kwargs["optional_params"]
+
+
+@pytest.mark.parametrize("max_retries", [0, 1, 5])
+@patch("litellm.images.main.openai_chat_completions")
+def test_max_retries_is_forwarded_to_the_openai_image_handler(mock_openai_chat_completions, max_retries):
+    mock_openai_chat_completions.image_generation.return_value = litellm.utils.ImageResponse(
+        created=1234567890, data=[{"url": "https://example.com/image.png"}]
+    )
+
+    image_generation(model="openai/dall-e-3", prompt="A red circle", max_retries=max_retries)
+
+    assert _optional_params(mock_openai_chat_completions)["max_retries"] == max_retries
+
+
+@patch("litellm.images.main.openai_chat_completions")
+def test_max_retries_is_absent_when_not_provided(mock_openai_chat_completions):
+    """The handler keeps its own default when the caller sets nothing."""
+    mock_openai_chat_completions.image_generation.return_value = litellm.utils.ImageResponse(
+        created=1234567890, data=[{"url": "https://example.com/image.png"}]
+    )
+
+    image_generation(model="openai/dall-e-3", prompt="A red circle")
+
+    assert "max_retries" not in _optional_params(mock_openai_chat_completions)
+
+
+def test_max_retries_zero_makes_one_upstream_request():
+    """End to end through the real OpenAI handler, against a local stub that 503s."""
+    import threading
+    from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
+
+    hits = []
+
+    class Stub(BaseHTTPRequestHandler):
+        def log_message(self, *args):
+            pass
+
+        def do_POST(self):
+            self.rfile.read(int(self.headers.get("content-length", 0) or 0))
+            hits.append(self.path)
+            self.send_response(503)
+            self.send_header("content-type", "application/json")
+            self.end_headers()
+            self.wfile.write(b'{"error": {"message": "unavailable", "type": "server_error"}}')
+
+    server = ThreadingHTTPServer(("127.0.0.1", 0), Stub)
+    threading.Thread(target=server.serve_forever, daemon=True).start()
+    try:
+        with pytest.raises(Exception):
+            image_generation(
+                model="openai/dall-e-3",
+                prompt="A red circle",
+                api_base=f"http://127.0.0.1:{server.server_address[1]}/v1",
+                api_key="sk-test",
+                max_retries=0,
+            )
+    finally:
+        server.shutdown()
+
+    assert len(hits) == 1