Error: error retrieving dynamodb table item serializationexception

A SerializationException while retrieving an item can mean DynamoDB could not decode the request, rather than that the stored item is corrupt. Check the complete exception and the request’s value format. Low-level and document APIs accept different shapes.

import boto3

db = boto3.client("dynamodb", region_name="us-west-2")
response = db.get_item(
    TableName="Orders",
    Key={"pk": {"S": "ORDER#123"}, "sk": {"S": "DETAIL"}},
)

# The resource interface uses native Python values instead.
table = boto3.resource("dynamodb", region_name="us-west-2").Table("Orders")
response = table.get_item(Key={"pk": "ORDER#123", "sk": "DETAIL"})

Do not pass a JSON-encoded string where the SDK expects a map, or wrap native resource values twice. Low-level Number values use numeric strings, BOOL uses a boolean, and Binary SDK input uses bytes. Check every table key against DescribeTable.

If the service read succeeds but mapping the response fails, inspect the application model and converter for the actual stored attribute type. Non-key attributes have no table-wide schema to repair. Authentication changes do not resolve malformed serialization.

See DynamoDB JSON formats and AWS documentation.