dynamodb-reserved-words

The complete list of 573 DynamoDB reserved words, as data, with helpers to check attribute names and generate the ExpressionAttributeNames aliases that unblock them. Zero dependencies.

DynamoDB reserves 573 words (name, status, date, year, count, and 568 more) that you can't use directly as attribute names in expressions. Hit one and the request fails with a ValidationException ("Attribute name is a reserved keyword; reserved keyword: status"). The fix is always the same: alias the name with a #-prefixed placeholder and map it in ExpressionAttributeNames. This package is that list and that fix.

The list is verbatim from the AWS Reserved words in DynamoDB reference (captured 2026-07-13, re-verified byte-identical 2026-08-15) and the count is pinned by tests, twice: the deduplicated set size and the raw token count, so a duplicate or a drift from the AWS page fails the build.

Install

npm install @dynotable/dynamodb-reserved-words

ESM and CJS, browser-safe.

Thirty seconds

import {checkNames, expressionAttributeNames} from '@dynotable/dynamodb-reserved-words';

const checks = checkNames(['userId', 'status', 'name']);
// [
//   {name: 'userId', reserved: false, alias: '#userId'},
//   {name: 'status', reserved: true,  alias: '#status'},
//   {name: 'name',   reserved: true,  alias: '#name'}
// ]

expressionAttributeNames(checks);
// {'#status': 'status', '#name': 'name'}   ← paste into your query params

import {isReserved} from '@dynotable/dynamodb-reserved-words';

isReserved('status'); // true (case-insensitive)
isReserved('userId'); // false

API

| Export | What it does | | --- | --- | | isReserved(word) | Case-insensitive membership check against the 573-word list. | | checkNames(names) | Check a list of attribute names. Each result carries a unique, collision-safe # alias. Blanks dropped, duplicates de-duplicated, order preserved. | | expressionAttributeNames(checks) | The ExpressionAttributeNames map for the reserved names in a checkNames result. Empty object when nothing is reserved. | | splitNames(input) | Split a pasted blob (newlines, commas, spaces, semicolons) into names. | | RESERVED_WORDS | The list as a ReadonlySet<string>, upper-cased. | | RESERVED_WORDS_RAW | The verbatim captured block, for auditing against the AWS page. | | reservedWordsByLetter() | The list grouped by initial letter, for rendering a reference. |

Alias generation handles the awkward cases: non-word characters collapse to _, colliding aliases get numeric suffixes, a name that cleans to nothing falls back to #attr. The output is always a valid ExpressionAttributeNames key.

Check names without installing anything

The same checker runs in the browser at dynotable.com/tools/dynamodb-reserved-words-checker, with the full browsable list.

License

MIT © DynoTable