External applications can interact with the The Ark via a secure web services interface. The interface was initially developed with a focus on allowing external applications to utilise The Ark's pedigree modelling and visualisation capabilities. To date, the web services layer facilitates the following functions:

• Create and edit study subjects
• Create and delete pedigree relationships
• Create and delete twin relationships
• Configure pedigree modelling and visualisation functionality
• For a given proband persisted in The Ark, retrieve an inferred pedigree membership, complete with relationship labels
• Generate and retrieve a pedigree visualisation for a proband persisted in The Ark
• Irrespective of existing studies and subjects stored in The Ark, send pedigree data and retrieve a corresponding visualisation without saving this data in The Ark.

Work on The Ark web services interface continues, and greater coverage of the system’s functionality will arrive in future releases.