Assuming that this part of the API is meant to be used like this: List<String> declIds = ); for( String declId: activation.getDeclarationIDs( ){ Object declVal = activation.getDeclarationValue( declId ); // ... } I'm using this during ActivationEvent logging. If, however, a fact is retracted, this code, when executed for an AfterActivationFiredEvent, throws a NPE when declId is a binding for a component of the retracted fact. The optimum solution would be to not get such useless bindings in the List<String> returned by getDeclarationIDs() which is in AgendaItem.java. I have added the if-statement: public List<String> getDeclarationIDs() { Declaration[] declArray = this.getRule().getDeclarations(); List<String> declarations = new ArrayList<String>(); for( Declaration decl : declArray ) { // return only "sound" declaration IDs if( this.tuple.get( decl ).getObject() != null ){ declarations.add( decl.getIdentifier() ); } } return Collections.unmodifiableList( declarations ); } This is untested! -W