Start with the actual file
The QuickBooks Online connector uploads supporting files to existing supported records. It does not provide Dropbox or Google Drive access. Your agent may have a separate authorized file integration that can retrieve the original document.
A sharing URL, local path, extracted text or another app’s file ID alone is not a native file attachment. Do not turn a sharing URL into a fabricated MCP file reference or make private files public just to upload them.
Choose the file source
- Dropbox or Google Drive: ask the agent to retrieve or download the original file using its available file integration. If that client cannot transfer the file, download it yourself and attach it to the chat or use the secure upload fallback below.
- Your computer: use a desktop agent with authorized access to the selected folder, or attach the file yourself. A path written in a message does not grant folder access.
- This conversation: use the actual file you attached, if the client supports native MCP file input.
The connector and file integration have separate permissions. A file being visible in one tool does not guarantee another tool can retrieve its bytes.
Upload and link it
- Confirm the QuickBooks company and the concrete transaction type and ID. An account register or report row must be resolved to the actual transaction; an Account is not an attachment target.
- If the client supplies a retrievable native file, use upload_attachment with that file and a stable operation ID.
- Otherwise, use create_attachment_upload or the secure browser_upload_url returned by the connector. Upload the original file, then continue with its payload_resource_id. Do not paste bytes or Base64 into a tool argument.
- Match supporting evidence to the right existing record using the document and transaction details; date and amount alone may be ambiguous.
The staged upload accepts 1 through 95,000,000 original bytes. Keep the original file unchanged unless you explicitly want it converted or compressed.
Give your agent the task
Name the source and existing target, and let the agent explain any file-transfer limitation.
Example prompt
Retrieve the original invoice PDF from the file source I have authorized, find the matching existing QuickBooks Online transaction and show me the intended attachment target. Attach the original file within my authorization. If this client cannot transfer it, give me the connector’s secure upload link instead of passing a sharing URL as a file.
Check the result
Use the connector’s confirmed upload result and inspect the attachment on the intended QuickBooks Online record when needed. Do not recreate the transaction to attach a file. If an upload’s outcome is uncertain, preserve its retry identifiers and resolve the outcome before starting a duplicate upload.