First-time setup for Durable Streams. Install @durable-streams/client, create a stream with DurableStream.create(), read with stream(), subscribe to live updates, resume from saved offsets. Covers offset semantics ("-1", "now", opaque tokens), LiveMode (false, true, "long-poll", "sse"), and StreamResponse consumption (.json(), .text(), .subscribeJson()).

Production readiness checklist for durable streams. Switch from dev server to Caddy binary, configure CDN caching with offset-based URLs, Cache-Control and ETag headers, Stream-Cursor for cache collision prevention, TTL and Stream-Expires-At for stream lifecycle, HTTPS requirement, request collapsing for fan-out, CORS configuration. Load before deploying durable streams to production.

Running durable stream servers. DurableStreamTestServer for development (Node.js, @durable-streams/server, not for production), Caddy plugin for production with Caddyfile configuration, data_dir for file-backed persistence, max_file_handles tuning, long_poll_timeout, server binary downloads for macOS Linux Windows, @durable-streams/cli tool setup, conformance test runner.

Defining typed state schemas for @durable-streams/state. createStateSchema() with CollectionDefinition (schema, type, primaryKey), Standard Schema validators (Zod, Valibot, ArkType), event helpers insert/update/delete/upsert, ChangeEvent and ControlEvent types, State Protocol operations, transaction IDs (txid) for write confirmation. Load when defining entity types, choosing a schema validator, or creating typed change events.

Stream-backed reactive database with @durable-streams/state. createStreamDB() with schema and stream options, db.preload() lazy initialization, db.collections for TanStack DB collections, optimistic actions with onMutate and mutationFn, db.utils.awaitTxId() for transaction confirmation, control events (snapshot-start, snapshot-end, reset), db.close() cleanup, re-exported TanStack DB operators (eq, gt, and, or, count, sum, avg, min, max).

Writing data to durable streams. DurableStream.create() with contentType, DurableStream.append() for simple writes, IdempotentProducer for high-throughput exactly-once delivery with autoClaim, fire-and-forget append(), flush(), close(), StaleEpochError handling, JSON mode vs byte stream mode, stream closure. Load when writing, producing, or appending data to a durable stream.

Yjs CRDT sync over durable streams with @durable-streams/y-durable-streams. DurableStreamsProvider setup, document stream and awareness stream config, transport modes (SSE vs long-poll), provider lifecycle (connect, disconnect, destroy), synced/status/error events, lib0 VarUint8Array framing, awareness heartbeat. Requires yjs, y-protocols, lib0 peer dependencies. Load when integrating Yjs collaborative editing with durable streams.