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    4.0.5 • Public • Published


    Simple key-value storage with support for multiple backends

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    Keyv provides a consistent interface for key-value storage across multiple backends via storage adapters. It supports TTL based expiry, making it suitable as a cache or a persistent key-value store.


    There are a few existing modules similar to Keyv, however Keyv is different because it:

    • Isn't bloated
    • Has a simple Promise based API
    • Suitable as a TTL based cache or persistent key-value store
    • Easily embeddable inside another module
    • Works with any storage that implements the Map API
    • Handles all JSON types plus Buffer
    • Supports namespaces
    • Wide range of efficient, well tested storage adapters
    • Connection errors are passed through (db failures won't kill your app)
    • Supports the current active LTS version of Node.js or higher


    Install Keyv.

    npm install --save keyv

    By default everything is stored in memory, you can optionally also install a storage adapter.

    npm install --save @keyv/redis
    npm install --save @keyv/mongo
    npm install --save @keyv/sqlite
    npm install --save @keyv/postgres
    npm install --save @keyv/mysql

    Create a new Keyv instance, passing your connection string if applicable. Keyv will automatically load the correct storage adapter.

    const Keyv = require('keyv');
    // One of the following
    const keyv = new Keyv();
    const keyv = new Keyv('redis://user:pass@localhost:6379');
    const keyv = new Keyv('mongodb://user:pass@localhost:27017/dbname');
    const keyv = new Keyv('sqlite://path/to/database.sqlite');
    const keyv = new Keyv('postgresql://user:pass@localhost:5432/dbname');
    const keyv = new Keyv('mysql://user:pass@localhost:3306/dbname');
    // Handle DB connection errors
    keyv.on('error', err => console.log('Connection Error', err));
    await keyv.set('foo', 'expires in 1 second', 1000); // true
    await keyv.set('foo', 'never expires'); // true
    await keyv.get('foo'); // 'never expires'
    await keyv.delete('foo'); // true
    await keyv.clear(); // undefined


    You can namespace your Keyv instance to avoid key collisions and allow you to clear only a certain namespace while using the same database.

    const users = new Keyv('redis://user:pass@localhost:6379', { namespace: 'users' });
    const cache = new Keyv('redis://user:pass@localhost:6379', { namespace: 'cache' });
    await users.set('foo', 'users'); // true
    await cache.set('foo', 'cache'); // true
    await users.get('foo'); // 'users'
    await cache.get('foo'); // 'cache'
    await users.clear(); // undefined
    await users.get('foo'); // undefined
    await cache.get('foo'); // 'cache'

    Custom Serializers

    Keyv uses json-buffer for data serialization to ensure consistency across different backends.

    You can optionally provide your own serialization functions to support extra data types or to serialize to something other than JSON.

    const keyv = new Keyv({ serialize: JSON.stringify, deserialize: JSON.parse });

    Warning: Using custom serializers means you lose any guarantee of data consistency. You should do extensive testing with your serialisation functions and chosen storage engine.

    Official Storage Adapters

    The official storage adapters are covered by over 150 integration tests to guarantee consistent behaviour. They are lightweight, efficient wrappers over the DB clients making use of indexes and native TTLs where available.

    Database Adapter Native TTL
    Redis @keyv/redis Yes
    MongoDB @keyv/mongo Yes
    SQLite @keyv/sqlite No
    PostgreSQL @keyv/postgres No
    MySQL @keyv/mysql No

    Third-party Storage Adapters

    You can also use third-party storage adapters or build your own. Keyv will wrap these storage adapters in TTL functionality and handle complex types internally.

    const Keyv = require('keyv');
    const myAdapter = require('./my-storage-adapter');
    const keyv = new Keyv({ store: myAdapter });

    Any store that follows the Map api will work.

    new Keyv({ store: new Map() });

    For example, quick-lru is a completely unrelated module that implements the Map API.

    const Keyv = require('keyv');
    const QuickLRU = require('quick-lru');
    const lru = new QuickLRU({ maxSize: 1000 });
    const keyv = new Keyv({ store: lru });

    The following are third-party storage adapters compatible with Keyv:

    Add Cache Support to your Module

    Keyv is designed to be easily embedded into other modules to add cache support. The recommended pattern is to expose a cache option in your modules options which is passed through to Keyv. Caching will work in memory by default and users have the option to also install a Keyv storage adapter and pass in a connection string, or any other storage that implements the Map API.

    You should also set a namespace for your module so you can safely call .clear() without clearing unrelated app data.

    Inside your module:

    class AwesomeModule {
    	constructor(opts) {
    		this.cache = new Keyv({
    			uri: typeof opts.cache === 'string' && opts.cache,
    			store: typeof opts.cache !== 'string' && opts.cache,
    			namespace: 'awesome-module'

    Now it can be consumed like this:

    const AwesomeModule = require('awesome-module');
    // Caches stuff in memory by default
    const awesomeModule = new AwesomeModule();
    // After npm install --save keyv-redis
    const awesomeModule = new AwesomeModule({ cache: 'redis://localhost' });
    // Some third-party module that implements the Map API
    const awesomeModule = new AwesomeModule({ cache: some3rdPartyStore });


    new Keyv([uri], [options])

    Returns a new Keyv instance.

    The Keyv instance is also an EventEmitter that will emit an 'error' event if the storage adapter connection fails.


    Type: String
    Default: undefined

    The connection string URI.

    Merged into the options object as options.uri.


    Type: Object

    The options object is also passed through to the storage adapter. Check your storage adapter docs for any extra options.


    Type: String
    Default: 'keyv'

    Namespace for the current instance.


    Type: Number
    Default: undefined

    Default TTL. Can be overridden by specififying a TTL on .set().


    Type: Function
    Default: JSONB.stringify

    A custom serialization function.


    Type: Function
    Default: JSONB.parse

    A custom deserialization function.

    Type: Storage adapter instance
    Default: new Map()

    The storage adapter instance to be used by Keyv.


    Type: String
    Default: undefined

    Specify an adapter to use. e.g 'redis' or 'mongodb'.


    Keys must always be strings. Values can be of any type.

    .set(key, value, [ttl])

    Set a value.

    By default keys are persistent. You can set an expiry TTL in milliseconds.

    Returns a promise which resolves to true.

    .get(key, [options])

    Returns a promise which resolves to the retrieved value.


    Type: Boolean
    Default: false

    If set to true the raw DB object Keyv stores internally will be returned instead of just the value.

    This contains the TTL timestamp.


    Deletes an entry.

    Returns a promise which resolves to true if the key existed, false if not.


    Delete all entries in the current namespace.

    Returns a promise which is resolved when the entries have been cleared.


    MIT © Jared Wray & Luke Childs


    npm i keyv

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