Error: missing required key 'key' in params dynamodb

Missing required key 'Key' in params means the request lacks the capitalized Key parameter required by GetItem, UpdateItem or DeleteItem. Supplying a field named key, or putting the identifier only inside Item, does not satisfy it.

import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, GetCommand } from "@aws-sdk/lib-dynamodb";

const db = DynamoDBDocumentClient.from(new DynamoDBClient({}));

const { Item } = await db.send(new GetCommand({
  TableName: "Orders",
  Key: { pk: "CUSTOMER#123", sk: "ORDER#42" },
}));
console.log(Item);

This table has a partition key and a sort key. Use the actual key names from DescribeTable and omit sk only if your table has no sort key. Make sure Key is not undefined after request construction or destructuring. A PutItem operation takes Item instead; Query uses a key condition rather than Key.

The original wording commonly appears in SDK v2 validation. The example uses SDK v3 and native values. Low-level GetItemCommand requires AttributeValue wrappers, while GetCommand does not.

See primary keys and AWS documentation.