Hey Michael,

I think the best way to get this same functionality is to use the SymXchange File API. Upload your file then call your poweron with the letter file name you uploaded.

While this query is not in the SDK yet it something we should get added. Below is something you could use to get you started.

import base64
import logging
import uuid
from typing import Type

from lxml.builder import E, ElementMaker
from q2_cores.SymXchange.models import namespaces
from q2_cores.SymXchange.models import Credentials, DeviceInformation
from q2_cores.SymXchange.queries.base_query import SymXchangeBaseQuery


class FileManagementQuery(SymXchangeBaseQuery):
    def __init__(
        self,
        logger: logging.Logger,
        file_name: str,
        file_contents: str,
        credentials: Type[Credentials],
        device_info: DeviceInformation,
        mock_failure: bool = False,
    ):
        self.file_name = file_name
        self.file_contents = file_contents
        super().__init__(logger, credentials, device_info, mock_failure)

    @property
    def service(self) -> str:
        return "filemanagement"
    
    def build(self) -> str:
        file = ElementMaker(
            namespace=namespaces.SYMXCHANGE_FILEMANAGEMENT,
            nsmap={"file": namespaces.SYMXCHANGE_FILEMANAGEMENT, "dto": namespaces.SYMXCHANGE_FILEMANAGEMENT_DTO}
        )
        file_dto = ElementMaker(
            namespace=namespaces.SYMXCHANGE_FILEMANAGEMENT_DTO
        )

        file_upload = file.uploadLetterFile(
            E.Request(
                {f'{{{namespaces.SYMXCHANGE_COMMON}}}MessageId' : str(uuid.uuid4())},
                self.create_credentials(),
                self.create_device_info(),
                file_dto.FileName(self.file_name),
                E.Data(base64.b64encode(self.file_contents.encode()).decode()),
                E.noNewline(str(False).lower())
            )
        )

        envelope = self.create_envelope(file_upload)

        return super().serialize(envelope)