diff --git a/syncbase/src/main/java/io/v/syncbase/Collection.java b/syncbase/src/main/java/io/v/syncbase/Collection.java
index 8742522..a6251e5 100644
--- a/syncbase/src/main/java/io/v/syncbase/Collection.java
+++ b/syncbase/src/main/java/io/v/syncbase/Collection.java
@@ -75,9 +75,9 @@
             if (vError.id.equals(VError.NO_EXIST)) {
                 return null;
             }
-            chainThrow("getting value from collection", mId, vError);
+            chainThrow("getting value from collection", mId.getName(), vError);
         } catch (VException e) {
-            chainThrow("decoding value retrieved from collection", mId, e);
+            chainThrow("decoding value retrieved from collection", mId.getName(), e);
         }
         throw new AssertionError("never happens");
     }
@@ -91,7 +91,7 @@
             return mCoreCollection.row(key).exists();
 
         } catch (VError e) {
-            chainThrow("checking if value exists in collection", mId, e);
+            chainThrow("checking if value exists in collection", mId.getName(), e);
             throw new AssertionError("never happens");
         }
     }
@@ -105,9 +105,9 @@
             mCoreCollection.put(key, VomUtil.encode(value, value.getClass()));
 
         } catch (VError e) {
-            chainThrow("putting value into collection", mId, e);
+            chainThrow("putting value into collection", mId.getName(), e);
         } catch (VException e) {
-            chainThrow("putting value into collection", mId, e);
+            chainThrow("putting value into collection", mId.getName(), e);
         }
     }
 
@@ -120,7 +120,7 @@
             mCoreCollection.delete(key);
 
         } catch (VError e) {
-            chainThrow("deleting collection", mId, e);
+            chainThrow("deleting collection", mId.getName(), e);
         }
     }
 
@@ -134,7 +134,7 @@
             return new AccessList(mCoreCollection.getPermissions());
 
         } catch (VError e) {
-            chainThrow("getting access list of collection", mId, e);
+            chainThrow("getting access list of collection", mId.getName(), e);
             throw new AssertionError("never happens");
         }
     }
@@ -155,7 +155,7 @@
                             coreCollection.getPermissions(), delta);
                     coreCollection.setPermissions(newPermissions);
                 } catch (VError vError) {
-                    chainThrow("setting permissions in collection", id, vError);
+                    chainThrow("setting permissions in collection", id.getName(), vError);
                 }
             }
         };
diff --git a/syncbase/src/main/java/io/v/syncbase/Database.java b/syncbase/src/main/java/io/v/syncbase/Database.java
index 00c0858..724d866 100644
--- a/syncbase/src/main/java/io/v/syncbase/Database.java
+++ b/syncbase/src/main/java/io/v/syncbase/Database.java
@@ -144,7 +144,7 @@
             return syncgroups.iterator();
 
         } catch (VError e) {
-            chainThrow("getting syncgroups of database", mCoreDatabase.id(), e);
+            chainThrow("getting syncgroups of database", mCoreDatabase.id().name, e);
             throw new AssertionError("never happens");
         }
     }
@@ -338,7 +338,7 @@
             }, opts.toCore());
 
         } catch (VError e) {
-            chainThrow("running batch operation in database", mCoreDatabase.id(), e);
+            chainThrow("running batch operation in database", mCoreDatabase.id().name, e);
         }
     }
 
@@ -383,7 +383,7 @@
             return new BatchDatabase(mCoreDatabase.beginBatch(opts.toCore()));
 
         } catch (VError e) {
-            chainThrow("creating batch in database", mCoreDatabase.id(), e);
+            chainThrow("creating batch in database", mCoreDatabase.id().name, e);
             throw new AssertionError("never happens");
         }
     }
diff --git a/syncbase/src/main/java/io/v/syncbase/DatabaseHandle.java b/syncbase/src/main/java/io/v/syncbase/DatabaseHandle.java
index 90a8761..07c05f9 100644
--- a/syncbase/src/main/java/io/v/syncbase/DatabaseHandle.java
+++ b/syncbase/src/main/java/io/v/syncbase/DatabaseHandle.java
@@ -94,7 +94,7 @@
             return collections.iterator();
 
         } catch (VError e) {
-            chainThrow("getting collections in database", mCoreDatabaseHandle.id(), e);
+            chainThrow("getting collections in database", mCoreDatabaseHandle.id().name, e);
             throw new AssertionError("never happens");
         }
     }
diff --git a/syncbase/src/main/java/io/v/syncbase/Syncgroup.java b/syncbase/src/main/java/io/v/syncbase/Syncgroup.java
index ef41110..ec0415e 100644
--- a/syncbase/src/main/java/io/v/syncbase/Syncgroup.java
+++ b/syncbase/src/main/java/io/v/syncbase/Syncgroup.java
@@ -91,7 +91,7 @@
             // return new AccessList(mCoreSyncgroup.getSpec().syncgroupSpec.permissions);
 
         } catch (VError e) {
-            chainThrow("getting access list of syncgroup", getId(), e);
+            chainThrow("getting access list of syncgroup", getId().getName(), e);
             throw new AssertionError("never happens");
         }
     }
@@ -187,7 +187,7 @@
             });
 
         } catch (VError e) {
-            chainThrow("updating access list of syncgroup", getId(), e);
+            chainThrow("updating access list of syncgroup", getId().getName(), e);
         }
     }
 }
diff --git a/syncbase/src/main/java/io/v/syncbase/WatchChange.java b/syncbase/src/main/java/io/v/syncbase/WatchChange.java
index b8ab288..1d007e5 100644
--- a/syncbase/src/main/java/io/v/syncbase/WatchChange.java
+++ b/syncbase/src/main/java/io/v/syncbase/WatchChange.java
@@ -78,7 +78,8 @@
         try {
             return (T) VomUtil.decode(mValue, cls);
         } catch (VException e) {
-            chainThrow("getting value from a WatchChange of collection",  mCollectionId, e);
+            chainThrow(
+                    "getting value from a WatchChange of collection",  mCollectionId.getName(), e);
             throw new AssertionError("never happens");
         }
     }
diff --git a/syncbase/src/main/java/io/v/syncbase/exception/Exceptions.java b/syncbase/src/main/java/io/v/syncbase/exception/Exceptions.java
index c01821c..5c08a38 100644
--- a/syncbase/src/main/java/io/v/syncbase/exception/Exceptions.java
+++ b/syncbase/src/main/java/io/v/syncbase/exception/Exceptions.java
@@ -7,7 +7,6 @@
 import java.util.NoSuchElementException;
 import java.util.concurrent.CancellationException;
 
-import io.v.syncbase.Id;
 import io.v.syncbase.core.VError;
 import io.v.v23.verror.VException;
 import io.v.v23.verror.VException.ActionCode;
@@ -119,28 +118,54 @@
         chainThrow("while " + javaMessage + " got error " + goMessage, v23ErrorId, action, cause);
     }
 
+    /**
+     * Throw an exception that wraps a low-level exception.
+     *
+     * @param javaMessage gives context from where the low-level exception was caught
+     * @param cause       the low-level exception, possibly originating in native code
+     * @throws SyncbaseException always
+     */
     public static void chainThrow(String javaMessage, VError cause) throws SyncbaseException {
         ActionCode action = fromValue((int) cause.actionCode);
         chainThrow(javaMessage, cause.message, cause.id, action, cause);
     }
 
+    /**
+     * Throw an exception that wraps a low-level exception.
+     *
+     * @param javaMessage gives context from where the low-level exception was caught
+     * @param cause       the low-level exception, possibly originating in native code
+     * @throws SyncbaseException always
+     */
     public static void chainThrow(String javaMessage, VException cause) throws SyncbaseException {
         chainThrow(javaMessage, cause.getMessage(), cause.getID(), cause.getAction(),
                 cause);
     }
 
-    public static void chainThrow(String doing, Id where, VError cause) throws SyncbaseException {
-        chainThrow(doing + " " + where.getName(), cause);
+    /**
+     * Throw an exception that wraps a low-level exception.
+     *
+     * @param doing what the high-level code was doing when the exception was caught
+     * @param name  a Vanadoum name, i.e the name field of an Id object
+     * @param cause the low-level exception, possibly originating in native code
+     * @throws SyncbaseException always
+     */
+    public static void chainThrow(String doing, String name, VError cause) throws
+            SyncbaseException {
+        chainThrow(doing + " " + name, cause);
     }
 
-    public static void chainThrow(String doing, Id where, VException cause) throws
+    /**
+     * Throw an exception that wraps a low-level exception.
+     *
+     * @param doing what the high-level code was doing when the exception was caught
+     * @param name  a Vanadoum name, i.e the name field of an Id object
+     * @param cause the low-level exception, possibly originating in native code
+     * @throws SyncbaseException always
+     */
+    public static void chainThrow(String doing, String name, VException cause) throws
             SyncbaseException {
-        chainThrow(doing + " " + where.getName(), cause);
-    }
-
-    public static void chainThrow(String doing, io.v.syncbase.core.Id where, VError cause) throws
-            SyncbaseException {
-        chainThrow(doing + " " + where.name, cause);
+        chainThrow(doing + " " + name, cause);
     }
 
     private static <T extends Exception> T withCause(T e, Exception cause) {