QuickBooks API: API Design & Integration Surface
Docs-backedREST API at quickbooks.api.intuit.com/v3/company/{realmId}/{resource}. QuickBooks Query Language (QQL) — SQL-like queries for reading data (SELECT * FROM Invoice WHERE DueDate < '2024-01-01'). Create/Update via POST with full entity JSON. Batch API supports up to 30 operations per request. CDC (change data capture) API for incremental sync. Webhook support for entity change events. Consistent response envelope: {QueryResponse: {...}} for queries.