Uploading attachments

The MCP server can attach a file (an invoice or a receipt) to Qonto without ever streaming the file bytes through the model’s context. It is a two-step handshake: the server hands your client a short-lived presigned upload URL, your client uploads the file straight to object storage, then the server forwards the staged file to Qonto. For reading, listing, or detaching attachments already on a transaction, see Transactions and statements.

The two-step flow

request_attachment_upload returns a short-lived presigned upload_url and an opaque blob_ref.
Your client uploads the file to upload_url with an HTTP PUT, sending the same Content-Type. The bytes go straight to object storage, never through the model.
upload_attachment takes the blob_ref and a target, reads the staged file, and pushes it to Qonto.

# Step 2: your client PUTs the raw bytes to the presigned URL
curl -X PUT \
  -H "Content-Type: application/pdf" \
  --upload-file invoice-2026-06.pdf \
  "$UPLOAD_URL"

Tools

Tool	What it does	Upstream
`request_attachment_upload`	Step 1. Returns a presigned `upload_url` (PUT), a `blob_ref`, the accepted `content_type`, the size limit, and an expiry. Accepts PDF, JPEG, and PNG up to 15 MB.	Object storage (presigned PUT)
`upload_attachment`	Step 2. Reads the staged `blob_ref` and forwards it to Qonto as the chosen `target`. The staged file is deleted once Qonto accepts it.	Depends on `target` (see below)

Targets

upload_attachment routes the file to one of four destinations via its target argument:

`target`	What it does	Returns	Upstream
`standalone`	Create a reusable attachment, not linked to anything yet.	`attachment_id`, to reference from a transfer, supplier invoice, or another `attachment_id` field.	Upload an attachment
`transaction`	Attach the file to a transaction (`transaction_id` required). Qonto processes it asynchronously, so it can take a few seconds to surface in `list_transaction_attachments`.	—	Upload an attachment to a transaction
`supplier_invoice`	Create a supplier invoice from the file. Qonto OCR then extracts the supplier, invoice number, dates, amounts, and VAT. The per-file limit is 10 MB.	The raw `response.supplier_invoices` and `response.errors` for the per-item outcome.	Create supplier invoices
`client_invoice`	Stage the file for a client invoice.	`upload_id`, to pass to `create_client_invoice` as `upload_id`.	Create a client invoice upload

Limits and formats

Formats: PDF, JPEG, PNG.
Size: up to 15 MB (10 MB for supplier_invoice).
Expiry: the presigned upload_url is valid for about 15 minutes. Request a fresh one if it lapses before the file is uploaded.

The presigned upload_url is a short-lived write credential to object storage. The server hands it to your client to upload the file; do not paste it into a chat where it may be logged or shared. Pass an idempotency_key to upload_attachment to make a retried upload safe.

Try it

Attach this receipt to my last Amazon transaction. Upload these supplier invoices and tell me the totals Qonto extracted. Create a draft client invoice for ACME from the attached PDF.

​The two-step flow

​Tools

​Targets

​Limits and formats

The two-step flow

Tools

Targets

Limits and formats