Begin Data is a durable and fast key/value document store built on top of DynamoDB

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Begin Data


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Begin Data is an easy to use, fast, and durable key/value and document store built on top of DynamoDB. Originally built for Begin serverless apps, Begin Data’s core API has three simple methods: get, set, and destroy.


Begin Data organizes itself into tables. A table contain documents which are just collections of plain Objects. Documents stored in Begin Data always have the properties table and key.
Optionally a document can also have a ttl property with a UNIX epoch value representing the expiry time for the document.


Begin Data operates on one DynamoDB table named data with a partition key scopeID and a sort key of dataID (and, optionally, a ttl for expiring documents).
Example app.arc:

  scopeID *String
  dataID **String
  ttl TTL

Or equivalent CloudFormation YAML:
AWSTemplateFormatVersion: "2010-09-09"
        Type: "AWS::DynamoDB::Table"
            TableName: "data"
            BillingMode: "PAY_PER_REQUEST"
                AttributeName: "scopeID"
                KeyType: "HASH"
                AttributeName: "dataID"
                KeyType: "RANGE"
                Enabled: "false"
                AttributeName: "ttl"
                Enabled: "TRUE"

Note: projects not based on Architect will need a BEGIN_DATA_TABLE_NAME environment variable. You can also use this env var to override and name the table anything you want. This also allows for multiple apps to share a single table.


let data = require('@begin/data')

The core API is three methods:
  • data.get(params[, callback])[Promise] for retreiving data
  • data.set(params[, callback])[Promise] for writing data
  • data.destroy(params[, callback])[Promise] for removing data

Additional helper methods are also made available:
  • data.incr(params[, callback])[Promise] increment an attribute on a document
  • data.decr(params[, callback])[Promise] decrement an attribute on a document
  • data.count(params[, callback])[Promise] get the number of documents for a given table

All methods accept a params object and, optionally, a Node-style errback. If no errback is supplied, a Promise is returned. All methods support async/await.


Save a document in a table by key. Remember: table is required; key is optional.
let taco = await data.set({
  table: 'tacos',
  key: 'al-pastor'

All documents have a key. If no key is given, set will generate a unique key.
let token = await data.set({
  table: 'tokens',
// {table:'tokens', key:'LCJkYX9jYWwidW50RhSU'}

Batch save multiple documents at once by passing an Array of Objects.
let collection = await data.set([
  {table: 'ppl', name:'brian', email:'b@brian.io'},
  {table: 'ppl', name:'sutr0', email:'sutr0@brian.io'},
  {table: 'tacos', key:'pollo'},
  {table: 'tacos', key:'carnitas'},


Read a document by key:
let yum = await data.get({
  table: 'tacos',
  key: 'baja'

Batch read by passing an Array of Objects. With these building blocks you can construct secondary indexes and joins, like one-to-many and many-to-many.
await data.get([
  {table:'tacos', key:'carnitas'},
  {table:'tacos', key:'al-pastor'},


Delete a document by key.
await data.destroy({
  table: 'tacos',
  key: 'pollo'

Batch delete documents by passing an Array of Objects.
await data.destroy([
  {table:'tacos', key:'carnitas'},
  {table:'tacos', key:'al-pastor'},


Large sets of data can not be retrieved in one call because the underlying get api paginates results. In this case use the for await syntax with a limit set to get paginated data.
let pages = data.page({ table:'ppl', limit:25 })
let count = 0  
for await (let page of pages) {

Additional Superpowers

  • Documents can be expired by setting ttl to an UNIX epoch in the future.
  • Atomic counters: data.incr and data.decr

See the tests for more examples!


Coming soon! Detailed guides for various data persistence tasks:
  • Denormalizing
  • Pagination
  • Counters
  • Secondary indexes
  • One to many
  • Many to many