in teamcity-invitations-plugin-server/src/main/java/org/jetbrains/teamcity/invitations/InvitationsFacadeApi.java [31:39]
public Invitation createJoinProjectInvitation(@NotNull SUser inviter, @NotNull String name, @NotNull SProject project,
@Nullable String roleId,
@Nullable String groupKey,
@NotNull String welcomeText,
boolean multiuser) {
String token = StringUtil.generateUniqueHash();
JoinProjectInvitationType.InvitationImpl created = joinProjectInvitationType.createNewInvitation(inviter, name, token, project, roleId, groupKey, multiuser, welcomeText);
return invitationsStorage.addInvitation(created);
}