Question: Support for bulk / batch transfers without using DAR files (Using Loop SDK)?

[Lakszy]

Loop SDK – Bulk / Batch Transfers

Docs:
https://docs.fivenorth.io/loop-sdk/overview/

I’m trying to bulk / batch transfers are possible using Loop SDK

My Setup

• I am NOT using any custom or third party DAR files

• I am interacting only through the Loop SDK APIs

• I have a DSO

• I understand that:

  • loop.wallet.transfer() supports only single transfers

My Question
Is it possible (or planned) to execute multiple transfers in one single transaction by submitting multiple commands in one DAML transaction?

Example (Concept)

provider.submitTransaction({
  commands: [
    { ExerciseCommand: { /* transfer 1 */ } },
    { ExerciseCommand: { /* transfer 2 */ } },
    { ExerciseCommand: { /* transfer 3 */ } },
  ]
});

Note: Using above approach, multiple transactions are sometimes supported in pop-ups, but sometimes they are not.

1. Multiple Commands

   • Is submitting multiple ExerciseCommands in one submitTransaction call supported by the Loop wallet flow?

2. Wallet Signing

   • Will the wallet prompt and sign only once for the full transaction?

3. SDK-Only Usage

   • Are there any limitations when doing this without using any DAR files directly?

Thanks in advance! 🙏

[Lakszy]

@tiffanytnpham @v9n @dinadeljanin
Please have a look when you get some time

[tiffanytnpham]

Hello,
Canton currently doesn't support a true atomic bulk transfer in a single ledger transaction. So multiple commands can't be passed in a single submitTransaction; that will return {"code":"FAILED_TO_PREPARE_TRANSACTION","cause":"The participant failed to prepare the transaction: Preparing multiple commands is currently not supported"...}.

To execute multiple transfers, each needs to be submitted as its own transaction. We are currently working on a helper to make running multiple transfers easier but it will still execute them sequentially (not as a single transaction).

[tiffanytnpham]

To follow up my earlier response:

• multiple ExcerciseCommands in a single submitTransaction are not supported for external parties right now.
• atomic bulk transfer is possible to run in a single transaction but only via our Bulk Transfer contract/helper
• we don't have public docs yet, but we're planning to add SDK support/documentation for this soon.

[Lakszy]

@tiffanytnpham
Thanks, understood
I can also see open PR for handling queued txn popups: #51
Thanks for your support!