OSS-first docs
These docs teach the open system first: contracts, generated surfaces, runtimes, governance, and incremental adoption. Studio shows up as the operating layer on top, not as the source of truth.
Contracts Runtime Core
The framework-neutral, in-house engine for the canonical ContractSpec data-fetching protocol. It owns caching, the durable offline queue, conflict resolution, and the ports (Transport, Storage, reachability) — with no `@tanstack/*` dependency and no React coupling. It depends only on `@lssm-tech/lib.contracts-spec` and `@lssm-tech/lib.observability`.
Installation
bun add @lssm-tech/lib.contracts-runtime-coreWhat it provides
Transport port
One `execute(envelope, ctx)` port (+ optional `subscribe()` realtime seam). REST, MCP, WebSocket, and in-memory are interchangeable adapters behind it.
Query + cache engine
In-house cache store keyed by `createQueryKey`, request dedup, retry/backoff, background revalidation, GC, and the canonical `QueryState` machine.
Offline + conflict
Durable mutation queue with replay-on-reconnect, optimistic apply/rollback, etag conflict detection, and a per-contract conflict-resolver registry (server-wins default; CRDT via crdt-loro injection).
Storage + reachability
Storage port with secure-by-default platform variants (`/storage/indexeddb` web, `/storage/async-storage` native) and a reachability input port the engine reads but never imports integrations for.
Engine setup
import {
createDataEngine,
createDataEngineFromEnv,
createMemoryStorage,
createStaticReachabilitySource,
type Transport,
type DataEngine,
} from '@lssm-tech/lib.contracts-runtime-core';
const engine: DataEngine = createDataEngine({
transport, // required: a Transport adapter (REST/MCP/in-memory)
localOffline, // optional: 'online-only' | 'memory-cache' | 'offline-capable'
env, // optional: host env (e.g. process.env); reads CONTRACTSPEC_LOCAL_OFFLINE
flag, // optional: feature-flag override (wins over env + default)
advanced: { // optional: low-level hatches used inside the selected mode
storage, // durable Storage port (defaults to in-memory)
reachability, // ReachabilitySource (defaults to always-online)
contextProvider, // fresh auth/correlation ctx per replay
refreshAuth, // () => Promise<boolean> for auth-expiry resume
},
});
// On/off trigger from the host environment in a single call. Precedence is
// flag > env > localOffline default; the core never reads global process.env
// itself — createDataEngineFromEnv is the only seam that injects it:
// CONTRACTSPEC_LOCAL_OFFLINE=offline-capable | memory-cache | online-only | on | off
const fromEnv: DataEngine = createDataEngineFromEnv({ transport });
// Surface: query / getState / subscribe / invalidateTags / refresh /
// emitConflict / mutate / drain / resume / dispose (+ events, maintenance)Related reading
For the full protocol, client hooks, server adapters, and rendering story, read the Data Fetching spec.
Libraries overview
Navigate the core libraries, runtimes, and system packages that make up the open foundation.
DataViews runtime
Render list, grid, and table DataViews with shared collection defaults, toolbar controls, data depth, and personalization bridges.
Why ContractSpec
Keep educational and comparison content reachable without letting it define the primary OSS learning path.