Zoho Campaigns EU Topics API returns HTTP 200 with empty topicDetails

Zoho Campaigns EU Topics API returns HTTP 200 with empty topicDetails

Hello, Our Zoho Campaigns EU organisation has two custom topics visible in the Campaigns UI, and contacts are subscribed to them. However, an OAuth request with ZohoCampaigns.contact.READ to https://campaigns.zoho.eu/api/v1.1/topics returns HTTP 200 with total_count 0 and an empty topicDetails array. The same happens with the v2 topics endpoint. The same OAuth token successfully reads our subscriber list and reports the expected contact, so authentication and organisation access otherwise appear correct. Could you please confirm: 1. Whether the Topics API is enabled for organisations on the current plan. 2. Whether there is a required EU endpoint, parameter, scope, or topic-management setting we are missing. 3. How to retrieve the topicId for an existing topic visible in the UI. 4. Whether Developer API access and topic-based campaigns remain available after a trial downgrades to Forever Free. We are holding off on any subscriber campaign until this is resolved. Regards, John