Rate Limiter

Class: RateLimiterBlockV1

Source: inference.core.workflows.core_steps.flow_control.rate_limiter.v1.RateLimiterBlockV1

The Rate Limiter block controls the execution frequency of a branch within a Workflow by enforcing a cooldown period. It ensures that the connected steps do not run more frequently than a specified interval, helping to manage resource usage and prevent over-execution.

Block usage

Rate Limiter is useful when you have two blocks that are directly connected, as shown below:

--- input_a --> ┌───────────┐ ┌───────────┐ --- input_b --> │ step_1 │ --> output_a --> │ step_2 │ --- input_c --> └───────────┘ └───────────┘

If you want to throttle the Step 2 execution rate - you should apply rate limiter in between:

• keep the existing blocks configuration as is (do not change connections)

• set depends_on reference of Rate Limiter into output_a

• set next_steps reference to be a list referring to [$steps.step_2]

• adjust cooldown_seconds to specify what is the number of seconds that must be awaited before next time when step_2 is fired

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.

Type identifier

Use the following identifier in step "type" field: roboflow_core/rate_limiter@v1to add the block as as step in your workflow.

Properties

Name	Type	Description	Refs
name	str	Enter a unique identifier for this step..	❌
cooldown_seconds	float	The minimum number of seconds between allowed executions..	❌

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 Rate Limiter in version v1.

• inputs: Byte Tracker, Distance Measurement, Time in Zone, Dot Visualization, Perspective Correction, Delta Filter, Blur Visualization, Clip Comparison, OpenAI, Keypoint Detection Model, EasyOCR, Stability AI Outpainting, VLM as Classifier, Twilio SMS Notification, Continue If, Google Vision OCR, Roboflow Dataset Upload, Email Notification, Instance Segmentation Model, Image Convert Grayscale, Detections Stabilizer, Bounding Box Visualization, Llama 3.2 Vision, Rate Limiter, Reference Path Visualization, Image Preprocessing, Local File Sink, First Non Empty Or Default, OpenAI, Image Slicer, Cosine Similarity, Detections Stitch, SIFT Comparison, Dominant Color, Velocity, Object Detection Model, Buffer, Stability AI Image Generation, SmolVLM2, Dimension Collapse, Cache Get, Roboflow Custom Metadata, SIFT Comparison, Model Comparison Visualization, Dynamic Zone, Line Counter, Time in Zone, QR Code Detection, Relative Static Crop, Polygon Visualization, Slack Notification, JSON Parser, Triangle Visualization, YOLO-World Model, Single-Label Classification Model, Detections Classes Replacement, Data Aggregator, Bounding Rectangle, Circle Visualization, Label Visualization, Google Gemini, VLM as Detector, Multi-Label Classification Model, Detections Merge, Path Deviation, CSV Formatter, Detections Consensus, Moondream2, Segment Anything 2 Model, Expression, LMM For Classification, Polygon Zone Visualization, VLM as Classifier, Identify Outliers, Morphological Transformation, Size Measurement, Corner Visualization, LMM, Pixel Color Count, Florence-2 Model, PTZ Tracking (ONVIF).md), Grid Visualization, Image Threshold, Florence-2 Model, Halo Visualization, Multi-Label Classification Model, CogVLM, Detection Offset, Detections Combine, Byte Tracker, Line Counter Visualization, Perception Encoder Embedding Model, Stitch OCR Detections, VLM as Detector, CLIP Embedding Model, Keypoint Detection Model, Identify Changes, Camera Focus, SIFT, Clip Comparison, Image Slicer, Keypoint Visualization, Template Matching, OCR Model, Line Counter, Instance Segmentation Model, Dynamic Crop, Roboflow Dataset Upload, Mask Visualization, Qwen2.5-VL, Background Color Visualization, Webhook Sink, Camera Calibration, Depth Estimation, QR Code Generator, Property Definition, Time in Zone, Trace Visualization, Detections Transformation, Contrast Equalization, Byte Tracker, Cache Set, Crop Visualization, Overlap Filter, Object Detection Model, Pixelate Visualization, Model Monitoring Inference Aggregator, Gaze Detection, Anthropic Claude, Barcode Detection, Image Contours, OpenAI, Path Deviation, Detections Filter, Classification Label Visualization, Image Blur, Absolute Static Crop, Stability AI Inpainting, Icon Visualization, Ellipse Visualization, Color Visualization, Environment Secrets Store, Single-Label Classification Model, Stitch Images
• outputs: None

Input and Output Bindings

The available connections depend on its binding kinds. Check what binding kinds Rate Limiter in version v1 has.

Bindings

• input

  • depends_on (*): Step immediately preceding this block..
  • next_steps (step): Steps to execute if allowed by the rate limit..
  • video_reference_image (image): Reference to a video frame to use for timestamp generation (if running faster than realtime on recorded video)..

• output

Example JSON definition of step Rate Limiter in version v1

{
    "name": "<your_step_name_here>",
    "type": "roboflow_core/rate_limiter@v1",
    "cooldown_seconds": 1.0,
    "depends_on": "$steps.model",
    "next_steps": [
        "$steps.upload"
    ],
    "video_reference_image": "$inputs.image"
}