Name	Description
`runCartAdapterContract`	Vitest-bound contract suite that every
`analytics`	Built-in middleware that calls the host-supplied
`compose`	Koa-style middleware composer: each layer wraps the next in registration order. With
`createCart`	Builds a cart kernel bound to one adapter. The kernel is the host-facing surface: it routes typed
`createEventBus`	In-process event bus used by the cart kernel to broadcast lifecycle events to UI layers (React store, analytics, tab sync). Delivery is fire-and-forget via
`idempotency`	Built-in middleware that deduplicates mutations sharing the same
`logger`	Built-in middleware that logs mutation lifecycle events via
`memoryIdempotencyStore`	In-memory
`retry`	Built-in middleware that retries transport / provider failures with linear backoff. Errors matched by
`tracing`	Built-in middleware that wraps each mutation in an OTel-shaped span. Span name is
`createMockCartAdapter`	Builds an in-memory cart adapter for host tests and contract self-tests. State lives in a

Classes

Name	Description
`CartCapabilityUnsupportedError`	Thrown by the kernel when a mutation requires a capability the active adapter doesn't advertise (e.g. gift cards on a provider without them).
`CartError`	Base class for every cart-core domain error. Consumers match on
`CartNotFoundError`	Thrown by adapters when a cart id is resolvable in the request but no cart exists upstream — distinct from a transport failure.
`CartProviderError`	Thrown for transport / upstream-API failures (network, 5xx, malformed payloads). Retry middleware treats this as retryable.
`CartUserError`	Thrown when the upstream provider rejects a mutation due to caller-supplied input (e.g. invalid discount code, quantity exceeds stock). Retry middleware does NOT retry these.

Interfaces

Name	Description
`RunCartAdapterContractOpts`	Options accepted by
`CartAdapter`	Contract that every cart provider implementation satisfies. Adapters expose required CRUD operations and declare their optional capabilities so the kernel can gate advanced mutations without probing method presence.
`CartEventBus`	In-process pub/sub channel through which the kernel broadcasts cart lifecycle events. Returned by
`CartKernel`	Host-facing surface returned by
`CreateCartOpts`	Configuration bag passed to
`IdempotencyStore`	Backing store contract for the
`ILogger`	Minimal structured-logging interface threaded through
`ITracer`	Minimal tracing interface accepted by the
`CreateMockCartAdapterOpts`	Options for

Types

Name	Description
`AdapterCtx`	Immutable context threaded into every adapter call by the kernel. Carries shop identity, locale, logger, and optional per-request signals so adapters never reach for global state.
`AnalyticsEmit`	Callback injected into the
`BuyerIdentity`	Optional contact details attached to an active cart to identify the buyer. Pass to
`Cart`	Full cart state returned by the kernel after every read or mutation. The
`CartActionFailureReason`	Machine-readable failure code surfaced on the
`CartActionResult`	Discriminated result returned by a
`CartCapabilities`	Feature flags advertised by every
`CartEvent`	Discriminated union of every lifecycle event the cart kernel can emit. Consumers subscribe via
`CartEventHandler`	Callback signature for a subscriber to a specific
`CartEventType`	Union of the string literal type discriminants for every
`CartExt`	Extension slot that lets adapter authors attach arbitrary provider-specific data to
`CartLine`	A single line item in a
`CartLineMerchandise`	Snapshot of the variant-level product data attached to a cart line. Captured at add-to-cart time so the cart displays correct titles and prices even when the variant is later modified or removed in the catalog.
`CartMiddleware`	Higher-order function that wraps a
`CartMutation`	Discriminated union of every operation the kernel can route to an adapter. Pass to
`CartUserErrorEntry`	A single field-scoped validation error returned by the upstream provider. Consumers display these to users;
`CurrencyCode`	ISO 4217 alphabetic currency code (e.g.
`CustomMutationHandler`	Handler registered on a
`KV`	Generic key-value pair used for cart attributes and line item attributes. Adapters map these to provider-specific metadata fields.
`LocaleTuple`	Language-country-currency triple that parameterizes every adapter call. Ensures currency is always co-located with locale so adapters never have to infer it from context.
`Money`	Decimal-string money amount paired with its currency code, matching the shape returned by most provider APIs. Pass to
`MoneyCents`	Integer-cents money representation used for all arithmetic inside the cart kernel. Avoids floating-point rounding by working in the currency's minor units. Convert back to
`MutationEnvelope`	Wraps a
`MutationFn`	Core mutation primitive: an async function that accepts a
`NewCartLine`	Minimal input needed to add a variant to a cart. Passed to
`ProductSnapshot`	Denormalized product data captured at add-to-cart time and carried on the
`SubmitMutation`	Server-action signature that transport layers (Next.js, Remix, tRPC) implement to accept a

Variables

Name	Description
`consoleLogger`	Default
`money`	Namespace of pure arithmetic helpers for

cart / core

Functions

Classes

Interfaces

Types

Variables

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