Response format
Every successful response from leadx-api goes through one helper, so the envelope is the same everywhere.
Pagination & sorting
Every list endpoint that goes through the shared query builder accepts the same parameters.
Searching & filtering
Three mechanisms, stackable. All are query-string parameters on list endpoints.
Bulk operations
LeadX has three distinct bulk mechanisms. Picking the right one matters — they have different limits and different failure behaviour.
Custom fields & formData
Leads, contacts and product/services all accept writes through a single formData object that mixes system fields and custom fields. Understanding how the two are told apart is the key to the whole write API.
Errors
Shape