General ledger
Balanced entries, source-owned journals, role-based posting, and corrections by reversal.
Open-source accounting for small businesses
Close the books with confidence.
Business Finlynq is a modular ERP foundation for teams that need multicurrency books, strong period controls, and a history that cannot quietly disappear.
- U.S. & Canada foundation
- Multicurrency by design
- Audit-first
- AGPL open source
Each browser receives an isolated synthetic business for the day. Try the accounting workflows, return after logout if needed, and expect the seeded setup to return nightly.
One accounting core
A clean foundation, expanded in modules.
Start with the workflows a small business needs today. Add inventory, projects, manufacturing, insurance, or other vertical modules without redesigning the ledger.
Receivables
Customer accounts, invoices, open items, tax decisions, and traceable subledger events.
Payables
Supplier bills, due-date visibility, control accounts, and a shared party address book.
Modular tax
Versioned jurisdiction packs designed first for Ontario and Washington, without hardwiring one country.
Control without bureaucracy
The system remembers what happened.
Entries are drafts until an authorized role posts them. Posted history is corrected through linked reversals. Closed periods narrow the path further, preserving evidence instead of relying on hidden delete buttons.
01Source ownershipAP entries return to AP. AR entries return to AR.
02Period stateOpen, adjustment-only, hard-closed, and sealed behavior.
03Corrections, not erasureVoid and reversal preserve who changed what and why.
Multicurrency that stays explainable
Never silently add unlike currencies.
Every posting keeps transaction and functional amounts, the applied rate, and its source. Current reports keep unlike currencies separate; policy-driven translation is planned as a later module.
- Entity-level functional currency
- Versioned exchange-rate provenance
- Realized and unrealized gain/loss policy
AI with the same permission boundary
Useful automation. Governed access.
Business Finlynq is being designed for future MCP access without creating a second security model. No public MCP endpoint is active in this preview. When enabled, reads and draft proposals will remain bounded by the user’s organization permissions, while posting, period close, and key administration stay explicit privileges.
ReadDraftValidatePost · privileged
Open by default
Own the code. Own the deployment path.
Business Finlynq is published under AGPL-3.0-or-later. The application, PostgreSQL database, encryption secrets, and edge configuration stay isolated so the service can move to another host without untangling it from Finlynq.
See the control model in context
Walk through a focused synthetic business.
No registration and no credentials to type. Sessions last up to one hour with a 15-minute idle limit; the same browser can reopen its private synthetic business until the nightly reset.