Kinesis Sink - Validation error detected on messages for tables with no PK

[corleyscotte]

Hey Sequin team,

I ran into an error when testing out the Kinesis Sink on a table with no primary keys.
Below is the error I am getting:

Failed to send message: [aws_kinesis]: Error from AWS: 5 validation errors detected: Value null at 'records.1.member.partitionKey' failed to satisfy constraint: Member must not be null; Value null at 'records.2.member.partitionKey' failed to satisfy constraint: Member must not be null; Value null at 'records.3.member.partitionKey' failed to satisfy constraint: Member must not be null; Value null at 'records.4.member.partitionKey' failed to satisfy constraint: Member must not be null; Value null at 'records.5.member.partitionKey' failed to satisfy constraint: Member must not be null (status=400)

Below is the message it was failing on (sanitized):

{
  "record": {
    "boolean_value": null,
    "case_id": 130619,
    "cell_id": 4079,
    "date_value": null,
    "edit_date": "2025-09-21T18:48:27.099761Z",
    "editor_puid": "pat:user:146",
    "field_id": 935,
    "float_value": null,
    "integer_value": null,
    "multi_select_value": [
      "b"
    ],
    "text_value": null,
    "transaction_id": "01996d9b-20e3-cacf-3f92-10ec7bc67e95",
    "transaction_source": "gql_mutation",
    "value_group_serial": 26209
  },
  "metadata": {
    "idempotency_key": "Mzk0NDE2OTEzNzQ4MDA6MQ==",
    "commit_lsn": 39441691374800,
    "commit_idx": 1,
    "record_pks": [],
    "commit_timestamp": "2025-09-21T18:48:27.116916Z",
    "table_name": "redacted_table_name",
    "table_schema": "public",
    "database_name": "redacted_dev",
    "transaction_annotations": null,
    "enrichment": null,
    "consumer": {
      "id": "b4faf43c-e3ea-463c-8a77-a80f77b84c1a",
      "name": "kinesis_redacted_topic_name",
      "annotations": {}
    },
    "database": {
      "id": "e3df10aa-4fed-46cd-abee-739bddbf3e9e",
      "name": "redacted_dev",
      "hostname": "redacted.us-east-1.rds.amazonaws.com",
      "annotations": {},
      "database": "redacted"
    }
  },
  "action": "insert",
  "changes": null
}

Let me know if you need additional information or testing to confirm this bug.

Thanks!