Webhook Sink¶
Class: WebhookSinkBlockV1
Source: inference.core.workflows.core_steps.sinks.webhook.v1.WebhookSinkBlockV1
The Webhook Sink block enables sending a data from Workflow into external APIs by sending HTTP requests containing workflow results.
How This Block Works¶
It supports multiple HTTP methods (GET, POST, PUT) and can be configured to send:
-
JSON payloads
-
query parameters
-
multipart-encoded files
This block is designed to provide flexibility for integrating workflows with remote systems for data exchange, notifications, or other integrations.
Setting Query Parameters¶
You can easily set query parameters for your request:
query_parameters = {
"api_key": "$inputs.api_key",
}
will send request into the following URL: https://your-host/some/resource?api_key=<API_KEY_VALUE>
Setting headers¶
Setting headers is as easy as setting query parameters:
headers = {
"api_key": "$inputs.api_key",
}
Sending JSON payloads¶
You can set the body of your message to be JSON document that you construct specifying json_payload
and json_payload_operations properties. json_payload works similarly to query_parameters and
headers, but you can optionally apply UQL operations on top of JSON body elements.
Let's assume that you want to send number of bounding boxes predicted by object detection model
in body field named detections_number, then you need to specify configuration similar to the
following:
json_payload = {
"detections_number": "$steps.model.predictions",
}
json_payload_operations = {
"detections_number": [{"type": "SequenceLength"}]
}
Multipart-Encoded Files in POST requests¶
Your endpoint may also accept multipart requests. You can form them in a way which is similar to
JSON payloads - setting multi_part_encoded_files and multi_part_encoded_files_operations.
Let's assume you want to send the image in the request, then your configuration may be the following:
multi_part_encoded_files = {
"image": "$inputs.image",
}
multi_part_encoded_files_operations = {
"image": [{"type": "ConvertImageToJPEG"}]
}
Cooldown¶
The block accepts cooldown_seconds (which defaults to 5 seconds) to prevent unintended bursts of
notifications. Please adjust it according to your needs, setting 0 indicate no cooldown.
During cooldown period, consecutive runs of the step will cause throttling_status output to be set True
and no notification will be sent.
Cooldown limitations
Current implementation of cooldown is limited to video processing - using this block in context of a
Workflow that is run behind HTTP service (Roboflow Hosted API, Dedicated Deployment or self-hosted
inference server) will have no effect for processing HTTP requests.
Async execution¶
Configure the fire_and_forget property. Set it to True if you want the request to be sent in the background,
allowing the Workflow to proceed without waiting on data to be sent. In this case you will not be able to rely on
error_status output which will always be set to False, so we recommend setting the fire_and_forget=False for
debugging purposes.
Disabling notifications based on runtime parameter¶
Sometimes it would be convenient to manually disable the Webhook sink block. This is possible
setting disable_sink flag to hold reference to Workflow input. with such setup, caller would be
able to disable the sink when needed sending agreed input parameter.
Common Use Cases¶
- Use this block to [purpose based on block type]
Connecting to Other Blocks¶
The outputs from this block can be connected to other blocks in your workflow.
Type identifier¶
Use the following identifier in step "type" field: roboflow_core/webhook_sink@v1to add the block as
as step in your workflow.
Properties¶
| Name | Type | Description | Refs |
|---|---|---|---|
name |
str |
Enter a unique identifier for this step.. | ❌ |
url |
str |
URL of the resource to make request. | ✅ |
method |
str |
HTTP method to be used. | ❌ |
query_parameters |
Dict[str, Union[List[Union[bool, float, int, str]], bool, float, int, str]] |
Request query parameters. | ✅ |
headers |
Dict[str, Union[bool, float, int, str]] |
Request headers. | ✅ |
json_payload |
Dict[str, Union[Dict[Any, Any], List[Any], bool, float, int, str]] |
Fields to put into JSON payload. | ✅ |
json_payload_operations |
Dict[str, List[Union[ClassificationPropertyExtract, ConvertDictionaryToJSON, ConvertImageToBase64, ConvertImageToJPEG, DetectionsFilter, DetectionsOffset, DetectionsPropertyExtract, DetectionsRename, DetectionsSelection, DetectionsShift, DetectionsToDictionary, Divide, ExtractDetectionProperty, ExtractFrameMetadata, ExtractImageProperty, LookupTable, Multiply, NumberRound, NumericSequenceAggregate, PickDetectionsByParentClass, RandomNumber, SequenceAggregate, SequenceApply, SequenceElementsCount, SequenceLength, SequenceMap, SortDetections, StringMatches, StringSubSequence, StringToLowerCase, StringToUpperCase, TimestampToISOFormat, ToBoolean, ToNumber, ToString]]] |
UQL definitions of operations to be performed on defined data w.r.t. each value of json_payload parameter. |
❌ |
multi_part_encoded_files |
Dict[str, Union[Dict[Any, Any], List[Any], bool, float, int, str]] |
Data to POST as Multipart-Encoded File. | ✅ |
multi_part_encoded_files_operations |
Dict[str, List[Union[ClassificationPropertyExtract, ConvertDictionaryToJSON, ConvertImageToBase64, ConvertImageToJPEG, DetectionsFilter, DetectionsOffset, DetectionsPropertyExtract, DetectionsRename, DetectionsSelection, DetectionsShift, DetectionsToDictionary, Divide, ExtractDetectionProperty, ExtractFrameMetadata, ExtractImageProperty, LookupTable, Multiply, NumberRound, NumericSequenceAggregate, PickDetectionsByParentClass, RandomNumber, SequenceAggregate, SequenceApply, SequenceElementsCount, SequenceLength, SequenceMap, SortDetections, StringMatches, StringSubSequence, StringToLowerCase, StringToUpperCase, TimestampToISOFormat, ToBoolean, ToNumber, ToString]]] |
UQL definitions of operations to be performed on defined data w.r.t. each value of multi_part_encoded_files parameter. |
❌ |
form_data |
Dict[str, Union[Dict[Any, Any], List[Any], bool, float, int, str]] |
Fields to put into form-data. | ✅ |
form_data_operations |
Dict[str, List[Union[ClassificationPropertyExtract, ConvertDictionaryToJSON, ConvertImageToBase64, ConvertImageToJPEG, DetectionsFilter, DetectionsOffset, DetectionsPropertyExtract, DetectionsRename, DetectionsSelection, DetectionsShift, DetectionsToDictionary, Divide, ExtractDetectionProperty, ExtractFrameMetadata, ExtractImageProperty, LookupTable, Multiply, NumberRound, NumericSequenceAggregate, PickDetectionsByParentClass, RandomNumber, SequenceAggregate, SequenceApply, SequenceElementsCount, SequenceLength, SequenceMap, SortDetections, StringMatches, StringSubSequence, StringToLowerCase, StringToUpperCase, TimestampToISOFormat, ToBoolean, ToNumber, ToString]]] |
UQL definitions of operations to be performed on defined data w.r.t. each value of form_data parameter. |
❌ |
request_timeout |
int |
Number of seconds to wait for remote API response. | ✅ |
fire_and_forget |
bool |
Boolean flag to run the block asynchronously (True) for faster workflows or synchronously (False) for debugging and error handling.. | ✅ |
disable_sink |
bool |
Boolean flag to disable block execution.. | ✅ |
cooldown_seconds |
int |
Number of seconds to wait until follow-up notification can be sent.. | ✅ |
The Refs column marks possibility to parametrise the property with dynamic values available
in workflow runtime. See Bindings for more info.
Available Connections¶
Compatible Blocks
Check what blocks you can connect to Webhook Sink in version v1.
- inputs:
Moondream2,Image Threshold,Stitch Images,Byte Tracker,Size Measurement,Keypoint Detection Model,Path Deviation,QR Code Generator,VLM As Classifier,Google Gemini,Qwen3.5-VL,Slack Notification,OpenAI,Motion Detection,Email Notification,Rate Limiter,Instance Segmentation Model,Roboflow Dataset Upload,Depth Estimation,Label Visualization,Camera Focus,Polygon Zone Visualization,OpenAI,Dimension Collapse,Template Matching,Background Color Visualization,Object Detection Model,Clip Comparison,SIFT Comparison,Image Preprocessing,CSV Formatter,Twilio SMS/MMS Notification,Reference Path Visualization,LMM For Classification,Florence-2 Model,Perspective Correction,Stitch OCR Detections,OpenAI,Time in Zone,Circle Visualization,Seg Preview,Stability AI Outpainting,Text Display,Line Counter,Detections Combine,Local File Sink,Google Gemini,Image Slicer,Ellipse Visualization,Byte Tracker,Halo Visualization,Model Comparison Visualization,Absolute Static Crop,Classification Label Visualization,Dominant Color,Image Slicer,Detections Stitch,Camera Focus,Barcode Detection,Time in Zone,Background Subtraction,Cosine Similarity,SAM 3,Heatmap Visualization,SIFT,CogVLM,Line Counter,Cache Set,Bounding Box Visualization,Polygon Visualization,Roboflow Custom Metadata,Pixelate Visualization,Pixel Color Count,SIFT Comparison,Detections Classes Replacement,Morphological Transformation,Perception Encoder Embedding Model,Detection Offset,Detection Event Log,VLM As Classifier,SmolVLM2,Twilio SMS Notification,Google Gemini,Detections Merge,Velocity,VLM As Detector,Keypoint Visualization,Multi-Label Classification Model,Mask Visualization,Instance Segmentation Model,Crop Visualization,Detections Stabilizer,Clip Comparison,Continue If,Property Definition,Segment Anything 2 Model,Stability AI Image Generation,VLM As Detector,Overlap Filter,Object Detection Model,Dot Visualization,Detections List Roll-Up,Contrast Equalization,Cache Get,Stitch OCR Detections,Llama 3.2 Vision,Detections Filter,Color Visualization,Florence-2 Model,Model Monitoring Inference Aggregator,JSON Parser,Dynamic Crop,Line Counter Visualization,PTZ Tracking (ONVIF),Blur Visualization,Triangle Visualization,Gaze Detection,OCR Model,Trace Visualization,Email Notification,CLIP Embedding Model,Byte Tracker,Image Convert Grayscale,First Non Empty Or Default,Expression,Single-Label Classification Model,YOLO-World Model,EasyOCR,Detections Consensus,Multi-Label Classification Model,Detections Transformation,SAM 3,Anthropic Claude,Path Deviation,QR Code Detection,Relative Static Crop,OpenAI,Keypoint Detection Model,Bounding Rectangle,Distance Measurement,Anthropic Claude,Corner Visualization,Buffer,Environment Secrets Store,Identify Outliers,Image Contours,Grid Visualization,Qwen2.5-VL,Identify Changes,Roboflow Dataset Upload,Image Blur,Webhook Sink,Stability AI Inpainting,LMM,Icon Visualization,Qwen3-VL,Google Vision OCR,Data Aggregator,Polygon Visualization,Anthropic Claude,Mask Area Measurement,SAM 3,Single-Label Classification Model,Time in Zone,Delta Filter,Dynamic Zone,Halo Visualization,Camera Calibration - outputs:
Moondream2,Image Threshold,Multi-Label Classification Model,Size Measurement,Keypoint Detection Model,Mask Visualization,Instance Segmentation Model,Path Deviation,Crop Visualization,QR Code Generator,Clip Comparison,Segment Anything 2 Model,Stability AI Image Generation,Google Gemini,Object Detection Model,Slack Notification,Dot Visualization,OpenAI,Motion Detection,Email Notification,Instance Segmentation Model,Roboflow Dataset Upload,Depth Estimation,Contrast Equalization,Cache Get,Label Visualization,Stitch OCR Detections,Llama 3.2 Vision,Polygon Zone Visualization,Color Visualization,OpenAI,Template Matching,Florence-2 Model,Model Monitoring Inference Aggregator,Dynamic Crop,Background Color Visualization,Object Detection Model,Line Counter Visualization,Image Preprocessing,PTZ Tracking (ONVIF),Blur Visualization,Triangle Visualization,Gaze Detection,Trace Visualization,Email Notification,Twilio SMS/MMS Notification,CLIP Embedding Model,Reference Path Visualization,Single-Label Classification Model,YOLO-World Model,LMM For Classification,Florence-2 Model,Perspective Correction,Stitch OCR Detections,OpenAI,Time in Zone,Circle Visualization,Detections Consensus,Seg Preview,Multi-Label Classification Model,SAM 3,Stability AI Outpainting,Text Display,Anthropic Claude,Line Counter,Path Deviation,OpenAI,Local File Sink,Google Gemini,Keypoint Detection Model,Distance Measurement,Ellipse Visualization,Halo Visualization,Anthropic Claude,Model Comparison Visualization,Corner Visualization,Classification Label Visualization,Detections Stitch,Time in Zone,SAM 3,Heatmap Visualization,CogVLM,Line Counter,Cache Set,Roboflow Dataset Upload,Polygon Visualization,Bounding Box Visualization,Pixelate Visualization,Roboflow Custom Metadata,Pixel Color Count,Image Blur,SIFT Comparison,Detections Classes Replacement,Webhook Sink,Stability AI Inpainting,Morphological Transformation,Perception Encoder Embedding Model,LMM,Icon Visualization,Twilio SMS Notification,Google Vision OCR,Polygon Visualization,Google Gemini,Anthropic Claude,Time in Zone,SAM 3,Single-Label Classification Model,Dynamic Zone,Halo Visualization,Camera Calibration,Keypoint Visualization
Input and Output Bindings¶
The available connections depend on its binding kinds. Check what binding kinds
Webhook Sink in version v1 has.
Bindings
-
input
url(string): URL of the resource to make request.query_parameters(Union[roboflow_project,integer,float_zero_to_one,boolean,float,roboflow_api_key,top_class,string,roboflow_model_id,list_of_values]): Request query parameters.headers(Union[roboflow_project,integer,float_zero_to_one,boolean,float,roboflow_api_key,top_class,string,roboflow_model_id]): Request headers.json_payload(*): Fields to put into JSON payload.multi_part_encoded_files(*): Data to POST as Multipart-Encoded File.form_data(*): Fields to put into form-data.request_timeout(integer): Number of seconds to wait for remote API response.fire_and_forget(boolean): Boolean flag to run the block asynchronously (True) for faster workflows or synchronously (False) for debugging and error handling..disable_sink(boolean): Boolean flag to disable block execution..cooldown_seconds(integer): Number of seconds to wait until follow-up notification can be sent..
-
output
Example JSON definition of step Webhook Sink in version v1
{
"name": "<your_step_name_here>",
"type": "roboflow_core/webhook_sink@v1",
"url": "<block_does_not_provide_example>",
"method": "<block_does_not_provide_example>",
"query_parameters": {
"api_key": "$inputs.api_key"
},
"headers": {
"api_key": "$inputs.api_key"
},
"json_payload": {
"field": "$steps.model.predictions"
},
"json_payload_operations": {
"predictions": [
{
"property_name": "class_name",
"type": "DetectionsPropertyExtract"
}
]
},
"multi_part_encoded_files": {
"image": "$steps.visualization.image"
},
"multi_part_encoded_files_operations": {
"predictions": [
{
"property_name": "class_name",
"type": "DetectionsPropertyExtract"
}
]
},
"form_data": {
"field": "$inputs.field_value"
},
"form_data_operations": {
"predictions": [
{
"property_name": "class_name",
"type": "DetectionsPropertyExtract"
}
]
},
"request_timeout": "$inputs.request_timeout",
"fire_and_forget": "$inputs.fire_and_forget",
"disable_sink": false,
"cooldown_seconds": "$inputs.cooldown_seconds"
}