LedgerLoom Chapter 10 — Accounts Payable Lifecycle

This chapter introduces Accounts Payable (A/P) as a control account + subledger pattern.

What you build

  • An opening balance carry-forward entry (same continuity idea as Chapter 08.5)

  • A tiny A/P operational flow:

    • vendor bills (A/P increases)

    • vendor credit memo (A/P decreases; reverses expense)

    • vendor payments (A/P decreases; cash decreases)

  • An open-items subledger with aging buckets

  • A control reconciliation: A/P control (G/L) equals sum(open items)

How to run

make ll-ch10

Artifacts

The chapter writes deterministic learning artifacts into outputs/ledgerloom/ch10:

  • vendor_bills_register.csv

  • vendor_credits_register.csv

  • cash_disbursements_register.csv

  • ap_open_items.csv (open items + aging)

  • ap_control_reconciliation.csv

Plus continuity artifacts (post-close snapshot, opening entry, reconciliation) and standard reports:

  • trial_balance_end_period.csv

  • income_statement_current_period.csv

  • balance_sheet_current_period.csv

Teachable checks

One bill is intentionally left unapproved so you can see how a checklist and invariants report can flag operational-policy violations.

See:

  • invariants.json → checks.all_bills_approved

  • ap_checklist.json → all_bills_approved