Moving money between two ERPs safely

The problem

The sync engine copies POS sessions, journal entries and purchases from one Odoo database to another. Before trusting it with more of the books, I audited it end to end in July 2026.

What I found

• A write that timed out could be retried automatically, so the same entry could be posted twice.
• The closing-cash figure was counting card revenue.
• Some failed posts and reconciliations were reported as successful.
• Stacked rules compounded each other instead of applying once.

What I did

• Never retry a call that writes: a timed-out write is checked on the target before anything else happens.
• Added sign-in to the app, and every money write is recorded against the person who approved it.
• Failures are reported as failures, and aborted runs can be resumed.
• Rules are evaluated with state, so stacked rules apply once.
• Added CI, an integration test harness on a real PostgreSQL database, and a refactor that cut code-quality warnings from 187 to 23.