Active Contract Set Service returns a Stream Arrays/List: how big can the arrays/List be per event in the stream?

Continuation of Java Bindings: ledgerClient.activeContractSetClient.getActiveContracts returns flowable but is it actually a stream? - #8 by Stephen

The ACS API returns a list of contracts in each event in the stream: Ledger API Reference — Daml SDK 2.2.0 documentation

But how big can each list be? What is the max number of contracts that will be returned per event?

Hi @StephenOTT,

Considering this sentence from the documentation you linked to:

The list of contracts that were introduced by the workflow with workflow_id

While the Ledger API does not guarantee this, in practice this means that each individual response message contains the number of CreatedEvents of a transaction, that were still active at the time of the request. So the maximum number of contracts in this list is the same as the number of contracts created in a transaction, that haven’t been archived yet.

Update: Keep in mind that the specific Ledger API implementation is also free to send one CreatedEvent per GetActiveContractsResponse. The comment above is about the upper bound of the list.

@gerolf thanks for that details. WorkflowID == transactionId ?

No, the workflowID can be used to associate multiple transactions to the same business workflow. This is a user/application provided field in the Commands message.

@gerolf so based on your previous two comments:

1. If workflow id was used /provided then the api call returns the contracts associated with that id (across multiple transactions)

2. If workflow id was not provided then the api returns contracts per transaction

?

In practice across recent releases of the Daml SDK, you will actually always get a single contract in each GetActiveContractsResponse.

@gerolf thanks!