Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The SharedStorageRunOperation interface of the Shared Storage API represents a Run output gate operation.

Instance methods

run() Experimental

Defines the structure to which the run() method defined inside a Run output gate operation should conform.


In this example, a class called ReachMeasurementOperation is defined in a worklet and is registered using SharedStorageWorkletGlobalScope.register() with the name reach-measurement. SharedStorageRunOperation defines the structure to which this class must conform, essentially defining the parameters required for the run() method. Other than this requirement, the functionality of the class can be defined flexibly.

// reach-measurement-worklet.js
const SCALE_FACTOR = 65536;

function convertContentIdToBucket(contentId) {
  return BigInt(contentId);

class ReachMeasurementOperation {
  async run(data) {
    const { contentId } = data;

    // Read from Shared Storage
    const key = "has-reported-content";
    const hasReportedContent = (await this.sharedStorage.get(key)) === "true";

    // Do not report if a report has been sent already
    if (hasReportedContent) {

    // Generate the aggregation key and the aggregatable value
    const bucket = convertContentIdToBucket(contentId);
    const value = 1 * SCALE_FACTOR;

    // Send an aggregatable report via the Private Aggregation API
    privateAggregation.sendHistogramReport({ bucket, value });

    // Set the report submission status flag
    await this.sharedStorage.set(key, true);

// Register the operation
register("reach-measurement", ReachMeasurementOperation);

Note: It is possible to define and register multiple operations in the same shared storage worklet module script with different names. See SharedStorageOperation for an example.

In the main browsing context, the reach-measurement operation is invoked using the method:

async function measureUniqueReach() {
  // Load the Shared Storage worklet
  await window.sharedStorage.worklet.addModule("reach-measurement-worklet.js");

  // Run the reach measurement operation
  await"reach-measurement", {
    data: { contentId: "1234" },


For more details about this example, see Unique reach measurement. See Shared Storage API for more examples.


Shared Storage API
# sharedstoragerunoperation

Browser compatibility

BCD tables only load in the browser

See also