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"
| 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 |
- 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.
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.
