Outbound List Import 500 Error via REST API

General Discussion
1

Why does this config cause a server error during list creation?

Attempting to automate outbound list ingestion via the Genesys Cloud REST API. The goal is to push CSV data directly into a new list using POST /api/v2/outbound/lists. The request returns 500 Internal Server Error. No specific error message in the response body. Just a generic failure.

Environment details:

  • Region: AU1
  • API Version: v2
  • Auth: OAuth Bearer Token (Service Account with outbound:outbound:read and outbound:outbound:write scopes)
  • Payload Format: JSON with base64 encoded CSV string

Snippet of the cURL command:

curl -X POST "https://api.au1.genesyscloud.com/api/v2/outbound/lists" \
 -H "Authorization: Bearer <TOKEN>" \
 -H "Content-Type: application/json" \
 -d '{
 "name": "TestList_Automation",
 "listData": {
 "data": "<BASE64_CSV>",
 "encoding": "base64"
 }
 }'

The list name is unique. The CSV format matches standard Genesys requirements. Manual upload via UI works fine. Is there a limitation on base64 payload size via API? Or is this a known issue in AU1?

2

Check your payload structure because the v2 endpoint expects a JSON object, not raw CSV data. Use the bulk contact import API (/api/v2/outbound/bulk/contacts) instead for CSV ingestion.