LGTM
http://gwt-code-reviews.appspot.com/1177801/diff/1/3 File user/src/com/google/gwt/autobean/shared/AutoBeanCodex.java (right): http://gwt-code-reviews.appspot.com/1177801/diff/1/3#newcode299 user/src/com/google/gwt/autobean/shared/AutoBeanCodex.java:299: encodeValue(ctx.getElementType(), element).getPayload()); Ta da, all the info needed for polymorphism on the wire, no? http://gwt-code-reviews.appspot.com/1177801/diff/1/4 File user/src/com/google/gwt/autobean/shared/ValueCodex.java (right): http://gwt-code-reviews.appspot.com/1177801/diff/1/4#newcode37 user/src/com/google/gwt/autobean/shared/ValueCodex.java:37: return value instanceof BigDecimal; No tests of BigDecimal upcast? http://gwt-code-reviews.appspot.com/1177801/diff/1/4#newcode53 user/src/com/google/gwt/autobean/shared/ValueCodex.java:53: return value instanceof BigInteger; ditto http://gwt-code-reviews.appspot.com/1177801/diff/1/5 File user/src/com/google/gwt/autobean/shared/ValueCodexHelper.java (right): http://gwt-code-reviews.appspot.com/1177801/diff/1/5#newcode27 user/src/com/google/gwt/autobean/shared/ValueCodexHelper.java:27: static boolean canDecode(Class<?> clazz) { Should you have a GWT.isClient() check return false, s.t. dev mode client acts like web mode client? http://gwt-code-reviews.appspot.com/1177801/show -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
