API V8 How to create a specific relationship when there is multiple of the same type

Hi there,

We’ve had to add a couple extra Account relationships to the Opportunities module for tracking 3rd party contractors on a few of our projects. Both of the new relationships are One-to-Many Accounts->Opportunities.

Now I’m trying to sync in opportunities from a secondary CRM using the JSON API.

path: {$API_PATH}/module/Opportunities/{$oppID}/relationships
data: Array (
    [data] => Array (
        [type] => Accounts
        [id] => {$accID}
    )
)

This all works fine and I’m getting a successful response message

response: Array (
    [meta] => stdClass Object (
        [message] => Account with id {$accID} has been added to Opportunity with id {$oppID}
    )
    [data] => Array (
    )
)

Except that it’s consistantly creating the relationship in the 3rd account. I need these relationships to always be created as the primary account but I can’t see any way to specify that via the API.