This schema of the data model excludes the meta-data, but you can also display a complete schema with meta-data.
schema AuthToken AuthToken enabled (Boolean) token (String) id (String) Blog Blog title (String) description (String) description_format (String) rss_url (String) BlogEntry BlogEntry title (String) content (String) content_format (String) BlogEntry->Blog entry_of 0..n 0..n Folder Folder name (String) description (String) description_format (String) BlogEntry->Folder filed_under 0..n 0..n UserAccount UserAccount name (String) BlogEntry->UserAccount has_creator 0..n 0..n Card Card title (String) synopsis (String) content (String) content_format (String) wikiid (String) Card->Folder filed_under 0..n 0..n Project Project name (String) summary (String) description (String) description_format (String) icon (Bytes) icon_format (String) homepage (String) downloadurl (String) Card->Project test_case_of 0..1 0..n Ticket Ticket title (String) description (String) description_format (String) priority (String) type (String) load (Float) load_left (Float) Card->Ticket test_case_for 0..1 0..n CheckResult CheckResult name (String) status (String) starttime (Datetime) endtime (Datetime) File File title (String) data (Bytes) data_format (String) data_encoding (String) data_name (String) data_sha1hex (String) description (String) description_format (String) CheckResult->File log_file 0..1 0..1 TestExecution TestExecution priority (Int) options (String) script (String) status (String) branch (String) keep_archive (Boolean) CheckResult->TestExecution during_execution 0..n CheckResultInfo CheckResultInfo type (String) label (String) value (String) CheckResultInfo->CheckResult for_check 0..n CheckResultInfo->TestExecution for_check 0..n Comment Comment content (String) content_format (String) Comment->BlogEntry comments 0..n Comment->Card comments 0..n Comment->Comment comments 0..n Email Email subject (String) date (Datetime) messageid (String) headers (String) Comment->Email comments 0..n Comment->Email generated_by 0..1 0..n Comment->File comments 0..n Link Link title (String) url (String) description (String) description_format (String) Comment->Link comments 0..n Task Task title (String) description (String) description_format (String) start (Datetime) stop (Datetime) Comment->Task comments 0..n TestInstance TestInstance name (String) Comment->TestInstance comments 0..n Comment->Ticket comments 0..n Email->Email cites 0..n 0..n Email->Email reply_to 0..1 0..n EmailPart EmailPart content (String) content_format (String) ordernum (Int) Email->EmailPart parts 0..n EmailThread EmailThread title (String) Email->EmailThread in_thread 0..1 0..n Email->File attachment 0..n 0..n MailingList MailingList name (String) mlid (String) description (String) description_format (String) email_address (String) archive (String) homepage (String) Email->MailingList sent_on 0..n 0..n EmailPart->EmailPart alternative EmailThread->EmailThread forked_from 0..1 0..n ExtProject ExtProject name (String) description (String) description_format (String) homepage (String) ExtProject->Folder filed_under 0..n 0..n File->Folder filed_under 0..n 0..n Folder->Folder filed_under 0..n 0..n InsertionPoint InsertionPoint lid (Int) Revision Revision description (String) author (String) changeset (String) branch (String) phase (String) vcstags (String) hidden (Boolean) InsertionPoint->Revision point_of 0..n InsertionPoint->Task has_activity 0..n 0..1 License License name (String) shortdesc (String) longdesc (String) longdesc_format (String) url (String) License->Project license_of 0..n 0..n Link->Folder filed_under 0..n 0..n MailingList->Project mailinglist_of 0..n 0..1 MicroBlog MicroBlog title (String) description (String) description_format (String) Patch Patch patch_name (String) Patch->Revision patch_revision 1..n 0..1 Patch->Task has_activity 0..n 0..1 Patch->Ticket patch_ticket 0..n 0..n Plan Plan priority (Int) options (String) script (String) Plan->File execution_log 0..1 0..1 Recipe Recipe name (String) script (String) Plan->Recipe execution_of 0..n Project->Card documented_by 0..n 0..n Project->File documented_by 0..n 0..n Project->File screenshot 0..n 0..n Project->Folder filed_under 0..n 0..n Project->Project subproject_of 0..1 0..n ProjectEnvironment ProjectEnvironment name (String) check_config (String) check_environment (String) vcs_path (String) Project->ProjectEnvironment has_apycot_environment 0..n 0..1 Repository Repository title (String) type (String) source_url (String) encoding (String) has_anonymous_access (Boolean) has_review (Boolean) use_global_groups (Boolean) Project->Repository source_repository 0..1 0..1 ProjectEnvironment->ProjectEnvironment refinement_of 0..1 0..n ProjectEnvironment->Repository local_repository 0..1 0..n Revision->Repository from_repository 0..n Revision->Revision obsoletes 0..n 0..n Revision->Revision parent_revision 0..n 0..n Tag Tag name (String) Tag->BlogEntry tags 0..n 0..n Tag->Card tags 0..n 0..n Tag->Email tags 0..n 0..n Tag->ExtProject tags 0..n 0..n Tag->File tags 0..n 0..n Tag->License tags 0..n 0..n Tag->Link tags 0..n 0..n Tag->MailingList tags 0..n 0..n Tag->Project tags 0..n 0..n Tag->Tag tags 0..n 0..n Tag->Ticket tags 0..n 0..n Version Version num (String) description (String) description_format (String) starting_date (Date) prevision_date (Date) publication_date (Date) progress_target (Float) progress_done (Float) progress_todo (Float) repository_branch (String) Tag->Version tags 0..n 0..n Task->Task depends_on 0..n 0..n TestConfig TestConfig name (String) label (String) start_mode (String) computed_start_mode (String) start_rev_deps (Boolean) check_config (String) check_environment (String) TestConfig->ProjectEnvironment use_environment 0..n 0..n TestConfig->Recipe use_recipe 0..1 0..n TestConfig->TestConfig refinement_of 0..1 0..n TestDependency TestDependency TestDependency->ProjectEnvironment for_environment 0..n TestDependency->ProjectEnvironment on_environment 0..n TestDependency->TestConfig for_testconfig 0..n TestExecution->File execution_archive 0..1 0..1 TestExecution->File execution_log 0..1 0..1 TestExecution->File log_file 0..1 0..1 TestExecution->Plan Parent class TestExecution->ProjectEnvironment using_environment 0..n TestExecution->Recipe execution_of 0..n TestExecution->Revision using_revision 0..n 0..n TestExecution->TestConfig using_config 0..n TestInstance->Card instance_of 0..n TestInstance->Ticket generate_bug 0..n 0..n TestInstance->Version for_version 0..n Ticket->File attachment 0..n 0..n Ticket->Project concerns 0..n Ticket->Revision closed_by 0..n 0..n Ticket->Revision introduced_by 0..n 0..n Ticket->Ticket depends_on 0..n 0..n Ticket->Ticket follow_up 0..1 0..1 Ticket->Ticket identical_to Ticket->Version done_in 0..1 0..n Version->Project version_of 0..n