Docs overview

The docs explain how SAPA behaves and how its pieces fit together. For a step-by-step first use, begin with the Guide. For exact exported signatures, use the API reference.

Core topics

• Mental model — definitions, accepted facts, derived state, and capabilities.
• Architecture — public facade, application contracts, storage, adapters, and composition roots.
• Domain glossary — the exact meaning of SAPA terms.
• Offers and purchases — immutable commercial terms and composable benefits.
• Exact money — minor-unit bigint values and JSON codecs.
• Idempotency — retry rules for every durable command.
• Runtime composition — services, Layers, and host-owned adapters.
• Errors and boundaries — validation, typed failures, and safe external handling.

Workflow guides

• Checkout and payments
• Subscriptions and metered billing
• Seats and prepaid credits
• Downloads and licensing
• Access checks and explanations

Build from an example

Use recipes for end-to-end product flows, integrations for host boundaries, and use cases for choosing a product shape.

Documentation contract

Narrative pages use public @byfungsi/sapa vocabulary. The generated reference starts from the package’s single public entrypoint. Internal workspace packages, storage rows, provider payloads, and deployment implementation details are not consumer APIs.