Oracle AI Agent Studio - Same Variables Resolve in Header but Not in Nested JSON Payload

Hi Community,

We are facing an issue with payload generation in Oracle AI Agent Studio while invoking a REST API from an agent workflow.

Our agent uses multiple tools to fetch business data (such as customer details, addresses, payment terms, etc.). The fetched values are then mapped to a JSON payload through prompt instructions before invoking the target REST API.

For example:

• One tool fetches PartyId.
• Another tool fetches PaymentTermsCode.
• In the prompt, we explicitly instruct the agent to reuse these fetched values in multiple locations within the payload.

Example payload template:

{
"BuyingPartyId": {PartyId},
"PaymentTermsCode": "{PaymentTermsCode}",
"billToCustomer": [
{
"PartyId": {PartyId}
}
],
"shipToCustomer": [