usm-core

Universal Schema Model — the storage- and transport-agnostic core.

A reflective, Hasura-style data-modeling engine for Node.js. This package holds everything that doesn't depend on a database or an API protocol:

• Vocabulary — SCALAR_TYPES, OPERATORS, OPERATORS_BY_TYPE, coerce.
• Schema — CollectionSchema (a table descriptor) and SearchSchema (a registry that resolves relationships and vends searchers). SearchSchema is storage-agnostic: it takes a searcher factory supplied by an adapter.
• Model bases — abstract Collection → KeyedCollection (key normalization + TTL/LRU cache over an abstract batchLoadByKeyValues) → ModelCollection (hydrated getByKey + search/aggregate), plus ModelType.
• Searcher contract — Searcher (implemented by adapters).
• Subscriptions — SubscriptionManager (cohort multiplexing + change-driven or polling refetch, pushes only on change) and the ChangeSource interface.

It depends on nothing GraphQL- or SQL-specific, so it can back multiple adapters (Postgres today) and multiple API layers (GraphQL today).

Install

npm install usm-core

Companion packages

• usm-adapter-postgres — knex/Postgres adapter: concrete searcher (the where/order_by → SQL compiler), knex collections, a SearchSchema factory, and a LISTEN/NOTIFY ChangeSource.
• usm-api-graphql — turns a SearchSchema into Hasura-style GraphQL (queries, aggregates, live-query subscriptions).

Shape

                usm-core  (this package)
                   ▲
        ┌──────────┴───────────┐
 usm-api-graphql        usm-adapter-postgres

Adapters and API layers depend on core; never on each other.