Estimate streaming payload size

Learn more about estimating the size of a streaming event payload for a destination and whether the object is classified as a large object.

Use the Streaming Payload Estimate to determine the event payload size for an entity or relation sent to a specific streaming destination and whether it exceeds that size limit. Estimating the payload size helps you identify and avoid unexpected size-limit failures before events are sent to the destination.

The Streaming Payload Estimate requires read privileges on entities, the same authorization as other data-read endpoints.

HTTP method and endpoint

Use the following HTTP method and endpoint path to submit the request for estimating the streaming payload size for an entity or relation on a given destination.

POST /{tenantId}/streaming/payloadEstimate

The following table describes the endpoint path parameters.


Parameter	Type	Required	Description
`tenantId`	String	Yes	The unique identifier of the tenant. Specifies the tenant context for the request.

Request headers

The following request headers must be included.


Header	Value	Required
`Authorization`	Bearer `<access_token>`	Yes
`Content-Type`	application/json	Yes

Request body

The following table describes the request body parameters, including accepted values and defaults.


Parameter	Type	Required	Description	Accepted values / Default
`objectUri`	String	Yes	URI of an existing entity or relation.	Example: `entities/{id}` or `relations/{id}`
`destinationName`	String	Yes	Name of a streaming destination configured for the tenant (queue or topic). Works even if the destination is currently disabled.	Example: `queue.MyTenant.allEvents`

Example request

Use the following example to see how a complete request is structured with headers and a JSON body.

POST /{tenantId}/streaming/payloadEstimate
Authorization: Bearer <access_token>
Content-Type: application/json
{
  "objectUri": "entities/ABC123",
  "destinationName": "my-destination"
}

Response body

The following table describes the fields returned in the response body.


Parameter	Type	Description
`payloadSizeBytes`	Number	Size (in bytes) of the message that would be sent to the destination for this object.
`isLargeObject`	Boolean	`true` if the estimated payload exceeds the destination's message-size limit. Note: If no publisher or connection is available for the destination, `payloadSizeBytes` falls back to the serialized body length and `isLargeObject` defaults to false.
`maxMessageSize`	Number	Maximum message size (in bytes) supported by the destination.

Example response

The following example shows a response with the estimated payload size and large-object classification.

{
    "payloadSizeBytes": 5718,
    "maxMessageSize": 1048576,
    "isLargeObject": false
}

Error codes and recommended actions

The following table lists the possible error responses returned by this API.


HTTP status	Description	Recommended action
400 Bad Request	Missing `objectUri` or `destinationName`, malformed object URI, URI does not point to an entity or relation, or unknown destination name.	Review the request payload, verify that `objectUri` and `destinationName` are valid, and resend the request.
404 Not Found	Object does not exist.	Verify that the entity or relation URI exists for the tenant, then resend the request.
503 Service Unavailable	Destination's messaging broker is unreachable.	Retry the request when the destination messaging broker is available.
500 Internal Server Error	An unexpected error occurred while processing the request.	Retry the request. If the issue persists, contact Reltio Support.

Payload estimate behavior and limitations

The endpoint evaluates the entity or relation as a full *_CREATED event (worst-case, full-object payload). For destinations configured with payloadType: DELTA, the reported size is a conservative upper bound, not the exact delta size.
The destination's objectFilter is not evaluated. The endpoint checks payload size only, not whether the entity or relation would actually be streamed to the destination.
The Streaming Payload Estimate differs from the Statistics API (GET entities/{id}/statistic with the is_large_object field), which measures internal queue-serialization size independent of any destination. The Streaming Payload Estimate API measures the resolved payload for a specific destination, accounting for destination-specific configuration such as payloadType, ovOnly, JMSEventsFilteringFields, and largeObjectsSupport.

Unify and manage your data