Configuration

SyncClientOptions reference for configuring the Strata Sync client.

Pass SyncClientOptions to createSyncClient.

Quick example


import { createSyncClient } from "@stratasync/client";

const client = createSyncClient({
  // Required adapters
  storage: storageAdapter,
  transport: transportAdapter,
  reactivity: reactivityAdapter,

  // Optional
  dbName: "my-app-sync",
  userId: "user-123",
  version: 1,
  userVersion: 1,
  groups: ["workspace-abc"],
  optimistic: true,
  batchMutations: true,
  batchDelay: 50,
  bootstrapMode: "auto",
  rebaseStrategy: "server-wins",
  fieldLevelConflicts: true,
});

Required adapters

storage

Type: StorageAdapter

Local persistence for model rows, metadata, the outbox, partial indexes, and sync actions.


import { createIndexedDbStorage } from "@stratasync/storage-idb";

const storage = createIndexedDbStorage();

The StorageAdapter interface defines methods for:

get, getAll, put, delete: basic CRUD for model rows
getByIndex: indexed lookups
getMeta, setMeta: sync metadata (last sync ID, schema hash, and more)
getOutbox, addToOutbox, removeFromOutbox: pending transaction persistence
hasPartialIndex, setPartialIndex: partial model index tracking
addSyncActions, getSyncActions, clearSyncActions: sync action log
writeBatch: batch write operations
clear, count: storage management

transport

Type: TransportAdapter

Server communication: bootstrap, delta subscriptions, batch mutations, and connection state.


import { createGraphQLTransport } from "@stratasync/transport-graphql";

const transport = createGraphQLTransport({
  endpoint: "https://api.example.com/graphql",
  syncEndpoint: "https://api.example.com/sync",
  wsEndpoint: "wss://api.example.com/sync/ws",
  auth: { getAccessToken: async () => "token" },
});

The TransportAdapter interface defines:

bootstrap(options): stream initial data as AsyncGenerator<ModelRow>
batchLoad(options): lazy-load models by index
mutate(batch): submit transaction batches
subscribe(options): real-time delta subscription
fetchDeltas(after, limit?): poll for missed deltas
getConnectionState(): current connection state
onConnectionStateChange(callback): subscribe to connection changes
close(): clean up resources

reactivity

Type: ReactivityAdapter

Makes identity map entries observable for UI re-rendering.


import { createMobXReactivity } from "@stratasync/mobx";

const reactivity = createMobXReactivity();

Simple options

All optional.

Option	Type	Default	Description
`dbName`	`string`	`"sync-db"`	Database name for storage. Each unique name creates a separate IndexedDB database.
`userId`	`string`	-	Logged-in user ID. Used for storage isolation in multi-user scenarios.
`version`	`number`	-	Client version for storage naming. Incrementing triggers a fresh bootstrap.
`userVersion`	`number`	-	Per-user version for storage naming. Incrementing triggers a fresh bootstrap.
`groups`	`string[]`	-	Sync groups for multi-tenancy. The client syncs only models belonging to the specified groups.
`optimistic`	`boolean`	`true`	Apply mutations to the identity map before the server confirms them. Rolls back on rejection.
`batchMutations`	`boolean`	`false`	Batch multiple mutations into a single network request.
`batchDelay`	`number` (ms)	-	Delay before sending a mutation batch. Only applies when `batchMutations` is `true`.
`bootstrapMode`	`"auto" \| "full" \| "local"`	`"auto"`	`auto`: use local storage if available and the schema matches, otherwise bootstrap from server. `full`: always bootstrap from server. `local`: never contact the server.
`schema`	`SchemaDefinition \| ModelRegistrySnapshot`	-	Explicit schema definition. If omitted, the client uses the global `ModelRegistry` populated by decorators.
`modelFactory`	`ModelFactory \| ModelFactoryFactory`	-	Custom factory for creating model instances from raw data. Defaults to `ModelRegistry` constructors with `_applyUpdate`.
`yjsTransport`	`YjsTransport`	-	Yjs transport for collaborative editing. Enables `client.yjs` with document and presence managers. See Y-Doc.

Conflict resolution

rebaseStrategy

Type: "server-wins" | "client-wins" | "merge": Default: "server-wins"

How the client resolves conflicts with concurrent server changes.

Strategy	Behavior
`"server-wins"`	Server changes take precedence. Client changes drop on conflict.
`"client-wins"`	Client changes take precedence. Server changes are overridden.
`"merge"`	Field-level merge. Non-conflicting fields from both sides are kept.

fieldLevelConflicts

Type: boolean: Default: true

Detect conflicts per-field rather than per-model. When enabled, non-overlapping field changes coexist without conflict.