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See Migrating to the Retail API from beta in the new documentation.

Method: projects.locations.catalogs.eventStores.userEvents.collect

Writes a single user event from the browser. This uses a GET request to due to browser restriction of POST-ing to a 3rd party domain.

This method is used only by the Recommendations AI JavaScript pixel. Users should not call this method directly.

HTTP request


The URL uses gRPC Transcoding syntax.

Path parameters



Required. The parent eventStore name, such as projects/1234/locations/global/catalogs/default_catalog/eventStores/default_event_store.

Query parameters



Required. URL encoded UserEvent proto.



Optional. The url including cgi-parameters but excluding the hash fragment. The URL must be truncated to 1.5K bytes to conservatively be under the 2K bytes. This is often more useful than the referer url, because many browsers only send the domain for 3rd party requests.


string (int64 format)

Optional. The event timestamp in milliseconds. This prevents browser caching of otherwise identical get requests. The name is abbreviated to reduce the payload bytes.

Request body

The request body must be empty.

Response body

If successful, the response is a generic HTTP response whose format is defined by the method.

Message that represents an arbitrary HTTP body. It should only be used for payload formats that can't be represented as JSON, such as raw binary or an HTML page.

This message can be used both in streaming and non-streaming API methods in the request as well as the response.

It can be used as a top-level request field, which is convenient if one wants to extract parameters from either the URL or HTTP template into the request fields and also want access to the raw HTTP body.


message GetResourceRequest {
  // A unique request id.
  string requestId = 1;

  // The raw HTTP body is bound to this field.
  google.api.HttpBody http_body = 2;


service ResourceService {
  rpc GetResource(GetResourceRequest)
    returns (google.api.HttpBody);
  rpc UpdateResource(google.api.HttpBody)
    returns (google.protobuf.Empty);


Example with streaming methods:

service CaldavService {
  rpc GetCalendar(stream google.api.HttpBody)
    returns (stream google.api.HttpBody);
  rpc UpdateCalendar(stream google.api.HttpBody)
    returns (stream google.api.HttpBody);


Use of this type only changes how the request and response bodies are handled, all other features will continue to work unchanged.

JSON representation
  "contentType": string,
  "data": string,
  "extensions": [
      "@type": string,
      field1: ...,


The HTTP Content-Type header value specifying the content type of the body.


string (bytes format)

The HTTP request/response body as raw binary.

A base64-encoded string.



Application specific response metadata. Must be set in the first response for streaming APIs.

An object containing fields of an arbitrary type. An additional field "@type" contains a URI identifying the type. Example: { "id": 1234, "@type": "" }.

Authorization Scopes

Requires the following OAuth scope:


For more information, see the Authentication Overview.