Cosigne by IT-TECH is a hosted connector that links ChatGPT or Claude to QuickBooks Online Canada.
Case Study: Cosigne
Overview
Cosigne connects ChatGPT or Claude to QuickBooks Online Canada. Ask questions about the books, check GST/HST, PST and QST on every transaction, and have the AI draft fixes. Nothing is written to QuickBooks without a person's approval. Data is stored in Canada (Québec), and Cosigne works in French and English.
Each person signs in from their own Claude or ChatGPT — Claude Code, Claude Desktop, or ChatGPT. There are no developer keys to manage and nothing to install.
What Cosigne Does
- Reads, searches and reports: profit and loss, balance sheet, aged receivables and payables, and a sales-tax review covering GST/HST, PST and QST.
- Drafts changes and explains them, then waits. Every change is approved by a person in the Cosigne web app before anything is written back.
- Firm controls: one login per bookkeeper, restrictions on which clients each person can reach, an activity log, and connections that can be revoked at any time.
What IT-TECH Built
- The hosted MCP server that exposes QuickBooks Online Canada to ChatGPT and Claude.
- The web app where drafted changes are reviewed and approved, with team management and billing.
- The bilingual marketing site, built and hosted on Cloudflare.
Hosting and Payments
Cosigne runs on OVHcloud in Beauharnois, Québec, so data stays in Canada. Payments are handled by Stripe.
QuickBooks and Intuit are trademarks of Intuit Inc. Claude is a trademark of Anthropic. ChatGPT is a trademark of OpenAI. Cosigne is an independent product and is not affiliated with, endorsed by, or sponsored by any of them.