QuickBooks Online

The connected company: CompanyName, Country, addresses. Also a cheap connection check.

No input parameters required.

Company preferences: CurrencyPrefs (HomeCurrency, MultiCurrencyEnabled), SalesFormsPrefs.CustomTxnNumbers (must be true to keep your own invoice number as DocNumber), TaxPrefs.

No input parameters required.

Run a read-only QuickBooks query, e.g. "select * from Invoice where DocNumber = '1001'", "select * from Customer where DisplayName = 'Acme Ltd'", "select * from TaxCode", "select * from Payment where MetaData.LastUpdatedTime > '2026-10-01T00:00:00Z'". Page with STARTPOSITION and MAXRESULTS (100 or less).

One customer by QuickBooks Id, including the SyncToken that update-customer needs.

Create a customer. DisplayName must be unique (customers, vendors and employees): look it up first with query. The same request_id returns the original result instead of a second customer, so a retry is safe. Other QuickBooks Customer fields pass through as given.

Update a customer; sparse, so only the fields you send change. Needs Id and the current SyncToken (get-customer); on a stale SyncToken read again and retry. Active false = inactive (no customer delete in QuickBooks).

One invoice by QuickBooks Id (not DocNumber): lines, TotalAmt, Balance (0 = paid), LinkedTxn (payments), SyncToken. Find one by your own number with query on DocNumber.

Create an invoice. Minimal: CustomerRef {"value": "<customer Id>"} and Line [{"DetailType": "SalesItemLineDetail", "Amount": 120.00, "Description": "...", "SalesItemLineDetail": {"ItemRef": {"value": "<item Id>"}, "Qty": 1, "UnitPrice": 120.00, "TaxCodeRef": {"value": "<tax code>"}}}]. Amounts are decimals, not cents; Amount = Qty x UnitPrice. DocNumber (your invoice number, max 21) is only kept when SalesFormsPrefs.CustomTxnNumbers is on; check with query that it is not used yet. The same request_id returns the original invoice instead of a second one. Other Invoice fields pass through as given.

Update an invoice; sparse, so only the fields you send change (a Line array replaces all lines). Needs Id and the current SyncToken (get-invoice); on a stale SyncToken read again and retry.

One payment by QuickBooks Id: TotalAmt, TxnDate, CustomerRef, PaymentMethodRef and Line[].LinkedTxn (the invoices it pays, TxnType Invoice).

Objects changed since a moment, e.g. entities "Invoice,Payment" and changed_since "2026-10-01T00:00:00Z". At most 30 days back and at most 1000 objects per entity; deleted objects come back with status "Deleted". Answer: CDCResponse[0].QueryResponse[] per entity.