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: VLM as Detector, Byte Tracker, Google Vision OCR, SAM 3, Overlap Filter, Detections Stabilizer, Image Preprocessing, LMM For Classification, Ellipse Visualization, Stitch Images, Triangle Visualization, Detections Combine, QR Code Generator, VLM as Classifier, Image Slicer, Background Color Visualization, Model Monitoring Inference Aggregator, Segment Anything 2 Model, Template Matching, Distance Measurement, Dot Visualization, EasyOCR, Halo Visualization, Data Aggregator, Slack Notification, Byte Tracker, Color Visualization, JSON Parser, Llama 3.2 Vision, QR Code Detection, Expression, Line Counter, Size Measurement, Email Notification, Delta Filter, Corner Visualization, Mask Visualization, Continue If, Time in Zone, Roboflow Custom Metadata, Stability AI Outpainting, Barcode Detection, Dominant Color, Time in Zone, Crop Visualization, VLM as Detector, Grid Visualization, Perspective Correction, Clip Comparison, Single-Label Classification Model, Contrast Equalization, Polygon Zone Visualization, CLIP Embedding Model, Bounding Box Visualization, Camera Focus, Icon Visualization, Image Blur, Time in Zone, Path Deviation, Environment Secrets Store, Anthropic Claude, Cosine Similarity, Multi-Label Classification Model, Dynamic Crop, Bounding Rectangle, Path Deviation, Detections Consensus, Model Comparison Visualization, Rate Limiter, Cache Get, Local File Sink, Identify Changes, Classification Label Visualization, Circle Visualization, SIFT Comparison, Image Contours, Relative Static Crop, Detections Filter, VLM as Classifier, Stability AI Inpainting, Moondream2, Velocity, OCR Model, Florence-2 Model, SIFT, Morphological Transformation, Detections Transformation, Reference Path Visualization, Gaze Detection, SIFT Comparison, Buffer, Polygon Visualization, Florence-2 Model, Image Slicer, Detection Offset, Clip Comparison, Perception Encoder Embedding Model, Image Convert Grayscale, OpenAI, Instance Segmentation Model, Line Counter, PTZ Tracking (ONVIF).md), Keypoint Detection Model, Object Detection Model, Google Gemini, Label Visualization, Email Notification, Byte Tracker, Trace Visualization, Dynamic Zone, YOLO-World Model, OpenAI, CogVLM, Detections Stitch, Stitch OCR Detections, Cache Set, Blur Visualization, CSV Formatter, Single-Label Classification Model, OpenAI, Detections Classes Replacement, Twilio SMS Notification, Absolute Static Crop, Seg Preview, Roboflow Dataset Upload, Roboflow Dataset Upload, Property Definition, Stability AI Image Generation, Webhook Sink, Depth Estimation, Dimension Collapse, Line Counter Visualization, Instance Segmentation Model, Multi-Label Classification Model, Pixelate Visualization, Image Threshold, Detections Merge, Keypoint Detection Model, LMM, Google Gemini, Identify Outliers, Pixel Color Count, SmolVLM2, Qwen2.5-VL, First Non Empty Or Default, Camera Calibration, Keypoint Visualization, Object Detection Model
• 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"
}