Implementation:Apache Druid LocalStorage Keys

Knowledge Sources	Apache_Druid
Domains	Web_Console, State_Persistence
Last Updated	2026-02-10 10:00 GMT

Overview

Defines a typed registry of localStorage keys and provides safe accessor functions for persisting web console state in the browser.

Description

The LocalStorage Keys module exports a `LocalStorageKeys` constant object mapping named identifiers (e.g., `QUERY_KEY`, `WORKBENCH_QUERIES`, `EXPLORE_STATE`) to their corresponding localStorage string keys. It also provides type-safe getter, setter, and removal functions that handle JSON serialization via `json-bigint-native`, gracefully degrade when localStorage is unavailable, and support an optional namespace prefix for key isolation.

Usage

Used throughout the web console to persist user preferences, query state, workbench configurations, table column selections, refresh rates, and explore view state across browser sessions.

Code Reference

Source Location

• Repository: Apache Druid
• File: web-console/src/utils/local-storage-keys.tsx
• Lines: 1-121

Signature

export const LocalStorageKeys: {
  CAPABILITIES_OVERRIDE: 'capabilities-override';
  INGESTION_SPEC: 'ingestion-spec';
  QUERY_KEY: 'druid-console-query';
  QUERY_CONTEXT: 'query-context';
  WORKBENCH_QUERIES: 'workbench-queries';
  EXPLORE_STATE: 'explore-state';
  WEB_CONSOLE_CONFIGS: 'web-console-configs';
  // ... and many more
};
export type LocalStorageKeys = (typeof LocalStorageKeys)[keyof typeof LocalStorageKeys];

export function setLocalStorageNamespace(namespace: string): void;
export function localStorageSet(key: LocalStorageKeys, value: string): void;
export function localStorageSetJson(key: LocalStorageKeys, value: any): void;
export function localStorageGet(key: LocalStorageKeys): string | undefined;
export function localStorageGetJson(key: LocalStorageKeys): any;
export function localStorageRemove(key: LocalStorageKeys): void;

Import

import { LocalStorageKeys, localStorageGet, localStorageSetJson } from './utils/local-storage-keys';

I/O Contract

Inputs

Name	Type	Required	Description
key	LocalStorageKeys	Yes	A typed localStorage key identifier from the LocalStorageKeys registry
value	any	Yes	The value to store; plain string for localStorageSet, any serializable value for localStorageSetJson
namespace	string	Yes	An optional prefix namespace to isolate localStorage keys

Outputs

Name	Type	Description
(return)	undefined	The raw stored string value, or undefined if not found (localStorageGet)
(return)	any	The JSON-parsed value, or undefined if not found or parse fails (localStorageGetJson)

Usage Examples

Store and retrieve a JSON value

import { LocalStorageKeys, localStorageSetJson, localStorageGetJson } from './utils/local-storage-keys';

localStorageSetJson(LocalStorageKeys.QUERY_CONTEXT, { sqlOuterLimit: 1000 });
const ctx = localStorageGetJson(LocalStorageKeys.QUERY_CONTEXT);
// ctx = { sqlOuterLimit: 1000 }

Use namespace isolation

import { setLocalStorageNamespace, localStorageSet, localStorageGet } from './utils/local-storage-keys';

setLocalStorageNamespace('my-instance');
localStorageSet(LocalStorageKeys.QUERY_KEY, 'SELECT 1');
// Stored under key 'my-instance:druid-console-query'

Related Pages

• Environment:Apache_Druid_Web_Console_Development