[Inference Providers] add image-to-image support for fal.ai provider

docs/source/en/guides/inference.md

@@ -218,7 +218,7 @@ For more details, refer to the [Inference Providers pricing documentation](https
 | [`~InferenceClient.fill_mask`]                      | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |
 | [`~InferenceClient.image_classification`]           | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |
 | [`~InferenceClient.image_segmentation`]             | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |
-| [`~InferenceClient.image_to_image`]                 | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |
+| [`~InferenceClient.image_to_image`]                 | ❌                 | ❌        | ❌      | ✅      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |
 | [`~InferenceClient.image_to_text`]                  | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |
 | [`~InferenceClient.object_detection`]               | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |  | ❌ |
 | [`~InferenceClient.question_answering`]             | ❌                 | ❌        | ❌      | ❌      | ❌              | ❌            | ❌    | ✅            | ❌          | ❌                | ❌         | ❌         | ❌         | ❌        |

src/huggingface_hub/inference/_client.py

@@ -1338,6 +1338,7 @@ def image_to_image(
             api_key=self.token,
         )
         response = self._inner_post(request_parameters)
+        response = provider_helper.get_response(response, request_parameters)
         return _bytes_to_image(response)
 
     def image_to_text(self, image: ContentT, *, model: Optional[str] = None) -> ImageToTextOutput:

src/huggingface_hub/inference/_generated/_async_client.py

@@ -1384,6 +1384,7 @@ async def image_to_image(
             api_key=self.token,
         )
         response = await self._inner_post(request_parameters)
+        response = provider_helper.get_response(response, request_parameters)
         return _bytes_to_image(response)
 
     async def image_to_text(self, image: ContentT, *, model: Optional[str] = None) -> ImageToTextOutput:

src/huggingface_hub/inference/_providers/__init__.py

@@ -12,6 +12,7 @@
 from .cohere import CohereConversationalTask
 from .fal_ai import (
     FalAIAutomaticSpeechRecognitionTask,
+    FalAIImageToImageTask,
     FalAITextToImageTask,
     FalAITextToSpeechTask,
     FalAITextToVideoTask,
@@ -78,6 +79,7 @@
         "text-to-image": FalAITextToImageTask(),
         "text-to-speech": FalAITextToSpeechTask(),
         "text-to-video": FalAITextToVideoTask(),
+        "image-to-image": FalAIImageToImageTask(),
     },
     "featherless-ai": {
         "conversational": FeatherlessConversationalTask(),

src/huggingface_hub/inference/_providers/fal_ai.py

@@ -1,7 +1,8 @@
 import base64
 import time
 from abc import ABC
-from typing import Any, Dict, Optional, Union
+from pathlib import Path
+from typing import Any, BinaryIO, Dict, Optional, Union
 from urllib.parse import urlparse
 
 from huggingface_hub import constants
@@ -32,6 +33,60 @@ def _prepare_route(self, mapped_model: str, api_key: str) -> str:
         return f"/{mapped_model}"
 
 
+class FalAIQueueTask(TaskProviderHelper, ABC):
+    def __init__(self, task: str):
+        super().__init__(provider="fal-ai", base_url="https://queue.fal.run", task=task)
+
+    def _prepare_headers(self, headers: Dict, api_key: str) -> Dict:
+        headers = super()._prepare_headers(headers, api_key)
+        if not api_key.startswith("hf_"):
+            headers["authorization"] = f"Key {api_key}"
+        return headers
+
+    def _prepare_route(self, mapped_model: str, api_key: str) -> str:
+        if api_key.startswith("hf_"):
+            # Use the queue subdomain for HF routing
+            return f"/{mapped_model}?_subdomain=queue"
+        return f"/{mapped_model}"
+
+    def get_response(
+        self,
+        response: Union[bytes, Dict],
+        request_params: Optional[RequestParameters] = None,
+    ) -> Any:
+        response_dict = _as_dict(response)
+
+        request_id = response_dict.get("request_id")
+        if not request_id:
+            raise ValueError("No request ID found in the response")
+        if request_params is None:
+            raise ValueError(
+                f"A `RequestParameters` object should be provided to get {self.task} responses with Fal AI."
+            )
+
+        # extract the base url and query params
+        parsed_url = urlparse(request_params.url)
+        # a bit hacky way to concatenate the provider name without parsing `parsed_url.path`
+        base_url = f"{parsed_url.scheme}://{parsed_url.netloc}{'/fal-ai' if parsed_url.netloc == 'router.huggingface.co' else ''}"
+        query_param = f"?{parsed_url.query}" if parsed_url.query else ""
+
+        # extracting the provider model id for status and result urls
+        # from the response as it might be different from the mapped model in `request_params.url`
+        model_id = urlparse(response_dict.get("response_url")).path
+        status_url = f"{base_url}{str(model_id)}/status{query_param}"
+        result_url = f"{base_url}{str(model_id)}{query_param}"
+
+        status = response_dict.get("status")
+        logger.info("Generating the output.. this can take several minutes.")
+        while status != "COMPLETED":
+            time.sleep(_POLLING_INTERVAL)
+            status_response = get_session().get(status_url, headers=request_params.headers)
+            hf_raise_for_status(status_response)
+            status = status_response.json().get("status")
+
+        return get_session().get(result_url, headers=request_params.headers).json()
+
+
 class FalAIAutomaticSpeechRecognitionTask(FalAITask):
     def __init__(self):
         super().__init__("automatic-speech-recognition")
@@ -110,23 +165,10 @@ def get_response(self, response: Union[bytes, Dict], request_params: Optional[Re
         return get_session().get(url).content
 
 
-class FalAITextToVideoTask(FalAITask):
+class FalAITextToVideoTask(FalAIQueueTask):
     def __init__(self):
         super().__init__("text-to-video")
 
-    def _prepare_base_url(self, api_key: str) -> str:
-        if api_key.startswith("hf_"):
-            return super()._prepare_base_url(api_key)
-        else:
-            logger.info(f"Calling '{self.provider}' provider directly.")
-            return "https://queue.fal.run"
-
-    def _prepare_route(self, mapped_model: str, api_key: str) -> str:
-        if api_key.startswith("hf_"):
-            # Use the queue subdomain for HF routing
-            return f"/{mapped_model}?_subdomain=queue"
-        return f"/{mapped_model}"
-
     def _prepare_payload_as_dict(
         self, inputs: Any, parameters: Dict, provider_mapping_info: InferenceProviderMapping
     ) -> Optional[Dict]:
@@ -137,36 +179,54 @@ def get_response(
         response: Union[bytes, Dict],
         request_params: Optional[RequestParameters] = None,
     ) -> Any:
-        response_dict = _as_dict(response)
+        output = super().get_response(response, request_params)
+        url = _as_dict(output)["video"]["url"]
+        return get_session().get(url).content
 
-        request_id = response_dict.get("request_id")
-        if not request_id:
-            raise ValueError("No request ID found in the response")
-        if request_params is None:
-            raise ValueError(
-                "A `RequestParameters` object should be provided to get text-to-video responses with Fal AI."
-            )
 
-        # extract the base url and query params
-        parsed_url = urlparse(request_params.url)
-        # a bit hacky way to concatenate the provider name without parsing `parsed_url.path`
-        base_url = f"{parsed_url.scheme}://{parsed_url.netloc}{'/fal-ai' if parsed_url.netloc == 'router.huggingface.co' else ''}"
-        query_param = f"?{parsed_url.query}" if parsed_url.query else ""
+class FalAIImageToImageTask(FalAIQueueTask):
+    def __init__(self):
+        super().__init__("image-to-image")
 
-        # extracting the provider model id for status and result urls
-        # from the response as it might be different from the mapped model in `request_params.url`
-        model_id = urlparse(response_dict.get("response_url")).path
-        status_url = f"{base_url}{str(model_id)}/status{query_param}"
-        result_url = f"{base_url}{str(model_id)}{query_param}"
+    def _prepare_payload_as_dict(
+        self, inputs: Any, parameters: Dict, provider_mapping_info: InferenceProviderMapping
+    ) -> Optional[Dict]:
+        if isinstance(inputs, str) and inputs.startswith(("http://", "https://")):
+            image_url = inputs
+        else:
+            image_bytes: bytes
+            if isinstance(inputs, (str, Path)):
+                with open(inputs, "rb") as f:
+                    image_bytes = f.read()
+            elif isinstance(inputs, bytes):
+                image_bytes = inputs
+            elif isinstance(inputs, BinaryIO):
+                image_bytes = inputs.read()
+            else:
+                raise TypeError(f"Unsupported input type for image: {type(inputs)}")
+
+            image_b64 = base64.b64encode(image_bytes).decode()
+            content_type = "image/png"
+            image_url = f"data:{content_type};base64,{image_b64}"
+        payload: Dict[str, Any] = {
+            "image_url": image_url,
+            **filter_none(parameters),
+        }
+        if provider_mapping_info.adapter_weights_path is not None:
+            lora_path = constants.HUGGINGFACE_CO_URL_TEMPLATE.format(
+                repo_id=provider_mapping_info.hf_model_id,
+                revision="main",
+                filename=provider_mapping_info.adapter_weights_path,
+            )
+            payload["loras"] = [{"path": lora_path, "scale": 1}]
 
-        status = response_dict.get("status")
-        logger.info("Generating the video.. this can take several minutes.")
-        while status != "COMPLETED":
-            time.sleep(_POLLING_INTERVAL)
-            status_response = get_session().get(status_url, headers=request_params.headers)
-            hf_raise_for_status(status_response)
-            status = status_response.json().get("status")
+        return payload
 
-        response = get_session().get(result_url, headers=request_params.headers).json()
-        url = _as_dict(response)["video"]["url"]
+    def get_response(
+        self,
+        response: Union[bytes, Dict],
+        request_params: Optional[RequestParameters] = None,
+    ) -> Any:
+        output = super().get_response(response, request_params)
+        url = _as_dict(output)["images"][0]["url"]
         return get_session().get(url).content

tests/test_inference_providers.py

@@ -21,6 +21,7 @@
 from huggingface_hub.inference._providers.fal_ai import (
     _POLLING_INTERVAL,
     FalAIAutomaticSpeechRecognitionTask,
+    FalAIImageToImageTask,
     FalAITextToImageTask,
     FalAITextToSpeechTask,
     FalAITextToVideoTask,
@@ -404,6 +405,73 @@ def test_text_to_video_response(self, mocker):
         mock_sleep.assert_called_once_with(_POLLING_INTERVAL)
         assert response == b"video_content"
 
+    def test_image_to_image_payload(self):
+        helper = FalAIImageToImageTask()
+        mapping_info = InferenceProviderMapping(
+            provider="fal-ai",
+            hf_model_id="stabilityai/sdxl-refiner-1.0",
+            providerId="fal-ai/sdxl-refiner",
+            task="image-to-image",
+            status="live",
+        )
+        payload = helper._prepare_payload_as_dict("https://example.com/image.png", {"prompt": "a cat"}, mapping_info)
+        assert payload == {"image_url": "https://example.com/image.png", "prompt": "a cat"}
+
+        payload = helper._prepare_payload_as_dict(
+            b"dummy_image_data", {"prompt": "replace the cat with a dog"}, mapping_info
+        )
+        assert payload == {
+            "image_url": f"data:image/png;base64,{base64.b64encode(b'dummy_image_data').decode()}",
+            "prompt": "replace the cat with a dog",
+        }
+
+    def test_image_to_image_response(self, mocker):
+        helper = FalAIImageToImageTask()
+        mock_session = mocker.patch("huggingface_hub.inference._providers.fal_ai.get_session")
+        mock_sleep = mocker.patch("huggingface_hub.inference._providers.fal_ai.time.sleep")
+        mock_session.return_value.get.side_effect = [
+            # First call: status
+            mocker.Mock(json=lambda: {"status": "COMPLETED"}, headers={"Content-Type": "application/json"}),
+            # Second call: get result
+            mocker.Mock(json=lambda: {"images": [{"url": "image_url"}]}, headers={"Content-Type": "application/json"}),
+            # Third call: get image content
+            mocker.Mock(content=b"image_content"),
+        ]
+        api_key = helper._prepare_api_key("hf_token")
+        headers = helper._prepare_headers({}, api_key)
+        url = helper._prepare_url(api_key, "username/repo_name")
+
+        request_params = RequestParameters(
+            url=url,
+            headers=headers,
+            task="image-to-image",
+            model="username/repo_name",
+            data=None,
+            json=None,
+        )
+        response = helper.get_response(
+            b'{"request_id": "test_request_id", "status": "PROCESSING", "response_url": "https://queue.fal.run/username_provider/repo_name_provider/requests/test_request_id", "status_url": "https://queue.fal.run/username_provider/repo_name_provider/requests/test_request_id/status"}',
+            request_params,
+        )
+
+        # Verify the correct URLs were called
+        assert mock_session.return_value.get.call_count == 3
+        mock_session.return_value.get.assert_has_calls(
+            [
+                mocker.call(
+                    "https://router.huggingface.co/fal-ai/username_provider/repo_name_provider/requests/test_request_id/status?_subdomain=queue",
+                    headers=request_params.headers,
+                ),
+                mocker.call(
+                    "https://router.huggingface.co/fal-ai/username_provider/repo_name_provider/requests/test_request_id?_subdomain=queue",
+                    headers=request_params.headers,
+                ),
+                mocker.call("image_url"),
+            ]
+        )
+        mock_sleep.assert_called_once_with(_POLLING_INTERVAL)
+        assert response == b"image_content"
+
 
 class TestFeatherlessAIProvider:
     def test_prepare_route_chat_completionurl(self):