Hello Harel's API uses a concept of shared references to keep track of resources used by external applications. This allows you to ignore Hello Harel's internal IDs and use your own instead.
For example, when you create an order for the first time using POST /api/v1/orders, you can identify the associated contact with:

"contact": { "externalReferenceId": "my_own_id", "firstName": "Jean", "lastName": "Martin", "email": "jean.martin@helloharel.com" },
Subsequent uses of this externalReferenceId will be associated with the same contact automatically.

If the Hello Harel instance provides a list of shared resources (obtained through e.g. GET /api/v1/contact_references), you can provide the internal ID for the shared resource through the (integer) internalReferenceId property:

"contact": { "internalReferenceId": <hello_harel_id>, "firstName": "Jean", "lastName": "Martin", "email": "jean.martin@helloharel.com" },

Affected resources are:

  • Contacts

  • Packagings

  • Shipping methods.