Local File Sink

Class: LocalFileSinkBlockV1

Source: inference.core.workflows.core_steps.sinks.local_file.v1.LocalFileSinkBlockV1

The Local File Sink block saves workflow data as files on a local file system. It allows users to configure how the data is stored, either:

• aggregating multiple entries into a single file

• or saving each entry as a separate file.

This block is useful for logging, data export, or preparing files for subsequent processing.

File Content, File Type and Output Mode

content is expected to be the output from another block producing string values of specific types denoted by file_type.

output_mode set into append_log will make the block appending single file with consecutive entries passed to content input up to max_entries_per_file. In this mode it is important that

file_type in append_log mode

Contrary to separate_files output mode, append_log mode may introduce subtle changes into the structure of the content to properly append it into existing file, hence setting proper file_type is crucial:

• file_type=json: in append_log mode, the block will create *.jsonl file in JSON Lines format - for that to be possible, each JSON document will be parsed and dumped to ensure that it will fit into single line.

• file_type=csv: in append_log mode, the block will deduct the first line from the content (making it required for CSV content to always be shipped with header row) of consecutive updates into the content of already created file.

Security considerations

The block has an ability to write to the file system. If you find this unintended in your system, you can disable the block setting environmental variable ALLOW_WORKFLOW_BLOCKS_ACCESSING_LOCAL_STORAGE=False in the environment which host Workflows Execution Engine.

If you want to restrict the directory which may be used to write data - set environmental variable WORKFLOW_BLOCKS_WRITE_DIRECTORY to the absolute path of directory which you allow to be used.

Type identifier

Use the following identifier in step "type" field: roboflow_core/local_file_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..	❌
file_type	str	Type of the file.	❌
output_mode	str	Decides how to organise the content of the file.	❌
target_directory	str	Target directory.	✅
file_name_prefix	str	File name prefix.	✅
max_entries_per_file	int	Defines how many datapoints can be appended to a single file.	✅

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 Local File Sink in version v1.

• inputs: Google Vision OCR, Keypoint Detection Model, LMM For Classification, Single-Label Classification Model, CSV Formatter, Roboflow Dataset Upload, Anthropic Claude, Florence-2 Model, Google Gemini, Google Gemini, Object Detection Model, EasyOCR, Email Notification, Anthropic Claude, Twilio SMS Notification, Llama 3.2 Vision, Clip Comparison, Email Notification, Slack Notification, VLM as Classifier, OpenAI, Model Monitoring Inference Aggregator, Local File Sink, OCR Model, Multi-Label Classification Model, OpenAI, LMM, Roboflow Dataset Upload, Webhook Sink, Instance Segmentation Model, OpenAI, OpenAI, Florence-2 Model, CogVLM, Roboflow Custom Metadata, VLM as Detector, Stitch OCR Detections
• outputs: Label Visualization, Blur Visualization, Background Color Visualization, Contrast Equalization, Reference Path Visualization, Stability AI Outpainting, Pixelate Visualization, Single-Label Classification Model, Perception Encoder Embedding Model, Seg Preview, Image Preprocessing, Color Visualization, SIFT Comparison, Email Notification, Cache Set, Circle Visualization, Object Detection Model, Moondream2, Model Monitoring Inference Aggregator, Path Deviation, LMM, Time in Zone, Morphological Transformation, Gaze Detection, Detections Consensus, Crop Visualization, OpenAI, Florence-2 Model, Classification Label Visualization, Segment Anything 2 Model, Time in Zone, YOLO-World Model, PTZ Tracking (ONVIF).md), Icon Visualization, Distance Measurement, Line Counter Visualization, Halo Visualization, Size Measurement, Dynamic Zone, Twilio SMS Notification, Time in Zone, Detections Stitch, Llama 3.2 Vision, Image Blur, Slack Notification, OpenAI, Multi-Label Classification Model, OpenAI, Dynamic Crop, Pixel Color Count, Mask Visualization, Google Vision OCR, LMM For Classification, Keypoint Visualization, Bounding Box Visualization, SAM 3, SAM 3, Object Detection Model, Path Deviation, Anthropic Claude, Polygon Zone Visualization, Ellipse Visualization, Line Counter, Email Notification, Clip Comparison, Roboflow Dataset Upload, SAM 3, CogVLM, Multi-Label Classification Model, Roboflow Custom Metadata, Keypoint Detection Model, Stitch OCR Detections, Keypoint Detection Model, Line Counter, Polygon Visualization, CLIP Embedding Model, Detections Classes Replacement, Cache Get, Triangle Visualization, Template Matching, Roboflow Dataset Upload, Anthropic Claude, Model Comparison Visualization, Corner Visualization, Florence-2 Model, Google Gemini, Google Gemini, Stability AI Image Generation, QR Code Generator, Dot Visualization, Local File Sink, Instance Segmentation Model, Stability AI Inpainting, Single-Label Classification Model, Webhook Sink, Instance Segmentation Model, Image Threshold, Perspective Correction, OpenAI, Trace Visualization

Input and Output Bindings

The available connections depend on its binding kinds. Check what binding kinds Local File Sink in version v1 has.

Bindings

• input

  • content (string): Content of the file to save.
  • target_directory (string): Target directory.
  • file_name_prefix (string): File name prefix.
  • max_entries_per_file (string): Defines how many datapoints can be appended to a single file.

• output

  • error_status (boolean): Boolean flag.
  • message (string): String value.

Example JSON definition of step Local File Sink in version v1

{
    "name": "<your_step_name_here>",
    "type": "roboflow_core/local_file_sink@v1",
    "content": "$steps.csv_formatter.csv_content",
    "file_type": "csv",
    "output_mode": "append_log",
    "target_directory": "some/location",
    "file_name_prefix": "my_file",
    "max_entries_per_file": 1024
}