I had the unfortunate need to understand the licensing model a little bit better recently for enabling editing in Office Web Apps. It's a little bit of a circuitous route so I thought I would just quickly detail it here. In short you want to:
So a complete PowerShell script for this would look something like this (assuming I'm using membership in an AD group called "OWA Editors" as the claim required to edit):
#NOTE: this is using an AD security group so I'm using the -SecurityGroup parameter#if I was using FBA, then instead I would use the -Role and -RoleProvider parameters#if I was using SAML, then instead I would use the -ClaimType, -OriginalProvider and #-Value parameters, or you can just use the -Claim with an SPClaim parameter$a = New-SPUserLicenseMapping -SecurityGroup "OWA Editors" –License OfficeWebAppsEdit$a | Add-SPUserLicenseMappingEnable-SPUserLicensingNew-OfficeWebAppsFarm -Verbose -InternalUrl https://<machinename> -ExternalUrl https://<fully.qualified.machine.name> -CertificateName <FriendlyNameOfCertificateFromPreviousStep> -ClipartEnabled -TranslationEnable -EditingEnabled
For more details on getting Office Web Apps set up in your farm you can also see my earlier post on it here: http://blogs.technet.com/b/speschka/archive/2012/07/23/configuring-office-web-apps-in-sharepoint-2013.aspx.