Schema Modes

Mnemonic supports optional schema versioning through the schemaMode prop on MnemonicProvider and an optional schemaRegistry. These features live on the schema-aware entrypoint:

import { MnemonicProvider } from "react-mnemonic/schema";

<MnemonicProvider namespace="app" schemaMode="default" schemaRegistry={registry}>
    <App />
</MnemonicProvider>

Available modes

default

Schemas are optional. Reads use a schema when one exists for the stored version, otherwise the hook codec. Writes use the highest registered schema for the key; if no schemas are registered, writes use an unversioned (v0) envelope.

This is the default mode — no configuration needed.

strict

Every stored version must have a registered schema. Reads without a matching schema fall back to defaultValue with a SchemaError. Writes require a registered schema when any schemas exist, but fall back to a v0 envelope when the registry has none.

<MnemonicProvider namespace="app" schemaMode="strict" schemaRegistry={registry}>
    <App />
</MnemonicProvider>

autoschema

Like default, but if no schema exists for a key, the first successful read infers and registers a v1 schema automatically. Subsequent reads/writes use that schema.

<MnemonicProvider namespace="app" schemaMode="autoschema" schemaRegistry={registry}>
    <App />
</MnemonicProvider>

Version zero

Version 0 is valid for schemas and migrations. Schemas at version 0 are treated like any other version. An unregistered key defaults to version 0.

Registry immutability

In default and strict modes, the schema registry is treated as immutable for the lifetime of the provider. The hook caches registry lookups to keep read and write hot paths fast. To ship new schemas or migrations, publish a new app version and remount the provider.

autoschema remains mutable because inferred schemas are registered at runtime.