# Billing, finance and economic evidence Model commercial lifecycles, exact money and reviewable financial handoffs with provider and country boundaries kept explicit. Source snapshot: bcc79fcc27c4d801c2119bef81ddcce7b4e86498 ## Choose the correct domain boundary BillingSpec models commercial parties, catalog/pricing, quotes, orders, invoices, credit notes, payments, reconciliation and related evidence. BillingRuntime supplies deterministic projections over those contracts with an injected tax-calculation port and backend-neutral persistence interfaces. The separate country package and provider integrations handle their specific responsibilities. Start by identifying the exact lifecycle and jurisdictional composition required by the host; a country-neutral operation declaration is not proof of configured production invoicing or payment execution. Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/spec/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/runtime/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/finance/runtime/README.md ## Preserve economic history The billing truth surface normalizes facts into an append-only evidence lifecycle with revision and idempotency checks. Corrections supersede earlier facts while retaining history. FinanceOS validates exact money, entity/tenant isolation, balanced postings, segregation of duties and budget freshness. Consequential work becomes a digest-bound handoff for host approval and execution. This division makes an accounting review reproducible: the reviewer can follow the original fact, its correction lineage and the proposed posting instead of trusting a mutable total. Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/spec/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/runtime/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/finance/runtime/README.md ## Respect unit and execution constraints Finance consolidation is holding-bound and homogeneous in currency and scale. Mixed units need governed conversion evidence and are denied by default in the documented runtime. BillingRuntime defines invoice, credit-note, event-log and invoice-chain ports rather than selecting a database or payment provider. Keep a proposed handoff, an authorized action and a confirmed external effect distinct in product copy and telemetry. Adapter qualification should address replay and ambiguous provider outcomes as well as the successful path. Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/spec/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/runtime/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/finance/runtime/README.md ## Trace one commercial transition Start with a quote or invoice reference and follow the declared operation, lifecycle projection and evidence event. Identify the exact money representation, tenant/company scope and persistence port involved. Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/spec/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/runtime/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/finance/runtime/README.md ## Inspect a correction and handoff Follow a superseding correction into the resulting finance proposal. Check balanced units, required evidence and the Connect authorization reference before considering the handoff eligible for a host executor. Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/spec/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/runtime/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/finance/runtime/README.md ## Choose the external boundary Locate the country and provider adapter used by the intended product. Review its credential, submission, reconciliation and failure responsibilities separately from the portable runtime; qualify that composition in its owning environment. Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/spec/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/billing/runtime/README.md Source: https://github.com/lssm-tech/contractspec/blob/bcc79fcc27c4d801c2119bef81ddcce7b4e86498/packages/domains/finance/runtime/README.md ## Packages - [@lssm-tech/lib.cost-tracking](https://lssm.co/docs/packages/lib.cost-tracking/): API cost tracking and budgeting - [@lssm-tech/lib.billing-france](https://lssm.co/docs/packages/lib.billing-france/): France-specific BillingOS readiness contracts and deterministic e-invoicing/e-reporting checks. - [@lssm-tech/lib.crypto-payments-spec](https://lssm.co/docs/packages/lib.crypto-payments-spec/): Provider-neutral crypto wallet governance and HTTP-native agent payment protocol contracts. - [@lssm-tech/lib.metering](https://lssm.co/docs/packages/lib.metering/): Usage metering and billing core module for ContractSpec applications - [@lssm-tech/module.billing-os](https://lssm.co/docs/packages/module.billing-os/): CompanyOS composition module for governed BillingOS action plans, authority checks, autonomy classification, and operator inbox routing. - [@lssm-tech/lib.billing-runtime](https://lssm.co/docs/packages/lib.billing-runtime/): Pure backend-neutral BillingOS runtime helpers for deterministic quote-to-cash lifecycle projections. - [@lssm-tech/lib.billing-spec](https://lssm.co/docs/packages/lib.billing-spec/): Country-neutral BillingOS quote-to-cash contracts, invariants, and agent action governance types. - [@lssm-tech/module.finance-os](https://lssm.co/docs/packages/module.finance-os/): Governed FinanceOS application services producing Connect-authorized effect handoffs. - [@lssm-tech/lib.finance-os-runtime](https://lssm.co/docs/packages/lib.finance-os-runtime/): Deterministic provider-neutral FinanceOS planning, budget, posting, and evidence runtime. - [@lssm-tech/lib.finance-ops-spec](https://lssm.co/docs/packages/lib.finance-ops-spec/): Provider-neutral internal finance operations contracts beyond BillingOS quote-to-cash.