An example prompt for a ledger app

Build a shared expense ledger for a housing co-op. It needs: double-entry ledger, money representation, accounts and wallets, holds and authorisations, idempotency layer and transfers saga. Rule that must always hold: every movement is a journal entry with balanced debit and credit lines. Balances are a cache of the journal. Entries are append-only; mistakes are corrected by reversing entries. The database enforces balance with a deferred constraint trigger. Leave out for now: no floating point money, ever and no custody of customer funds outside a licensed partner; the app is not a bank or money transmitter.

Replace the first sentence with your own idea. The list of needs stays useful whatever the niche, because it comes from what a ledger app has to do.

• Build a small-business bookkeeping tool with double-entry accounts. Start with double-entry ledger and money representation, and add accounts and wallets once those work.
• Build a wallet and transfers app for a members' club. People should be able to reserve funds for pending actions (card auth, pending payout) without moving them.

Forge AI picks a reference architecture from how you describe the app. These phrases point to a ledger app: fintech, neobank, digital wallet, e-wallet, wallet app, double-entry, double entry and ledger.

• Double-entry immutable journal as the source of truth.
• Integer minor units with explicit currency.
• Strong consistency via row locks / SERIALIZABLE, idempotency keys on every money API.

This is a reference design for the category, not a promise that every item is generated today. Built-ins such as email, background jobs, file uploads and search are coming soon, so anything here that needs them is something you add yourself for now.

• Sanctions/PEP screening and transaction-monitoring service: provider-run, needed once volume or jurisdiction requires it.
• Read replicas for history and statements: primary handles phase-1 load.
• Message broker and outbox publisher (Kafka or similar): Postgres jobs and NOTIFY suffice until downstream consumers exist.
• HSM / managed KMS for field encryption keys: env-held keys are acceptable at low risk.

How detailed should a prompt for a ledger app be?

Name the users, the main objects, one rule that must always hold and one thing to leave out. The plan fills in the rest, and you can change it before generation.

Which words tell Forge64 this is a ledger app?

Phrases such as fintech, neobank, digital wallet and e-wallet point to this category.

Can I change the app after the first build?

Yes. Describe the change in plain English and Forge AI edits the app; the quality gate checks the code again.

• How to build a ledger app
• Ledger app architecture
• Ledger app security checklist
• Ledger app scaling checklist
• Often combined: marketplace
• Often combined: SaaS dashboard
• All app types