diff --git a/main/src/com/google/refine/browsing/Engine.java b/main/src/com/google/refine/browsing/Engine.java
index 4feb97ec8..204e8a11e 100644
--- a/main/src/com/google/refine/browsing/Engine.java
+++ b/main/src/com/google/refine/browsing/Engine.java
@@ -41,6 +41,7 @@ import java.util.stream.Collectors;
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonValue;
 
@@ -69,8 +70,9 @@ public class Engine  {
     public final static String MODE_RECORD_BASED = "record-based";
 
     protected Project _project;
+    @JsonProperty("facets")
     protected List<Facet> _facets = new LinkedList<Facet>();
-    @JsonValue
+    @JsonIgnore
     protected EngineConfig _config = new EngineConfig(Collections.emptyList(), Mode.RowBased);
 
     static public String modeToString(Mode mode) {
@@ -84,6 +86,7 @@ public class Engine  {
         _project  = project;
     }
 
+    @JsonProperty("engine-mode")
     public Mode getMode() {
         return _config.getMode();
     }
diff --git a/main/src/com/google/refine/browsing/facets/ListFacet.java b/main/src/com/google/refine/browsing/facets/ListFacet.java
index 07ecf61f0..521af7858 100644
--- a/main/src/com/google/refine/browsing/facets/ListFacet.java
+++ b/main/src/com/google/refine/browsing/facets/ListFacet.java
@@ -231,16 +231,18 @@ public class ListFacet implements Facet {
     @JsonProperty("choiceCount")
     @JsonInclude(Include.NON_NULL)
     public Integer getChoiceCount() {
-        if (_errorMessage == null && _choices.size() > getLimit()) 
+        if (_errorMessage == null && _choices.size() > getLimit()) {
             return _choices.size();
+        }
         return null;
     }
     
     @JsonProperty("choices")
     @JsonInclude(Include.NON_NULL)
     public List<NominalFacetChoice> getChoices() {
-        if (getError() == null)
+        if (getError() == null) {
             return _choices;
+        }
         return null;
     }
     
diff --git a/main/src/com/google/refine/commands/GetPreferenceCommand.java b/main/src/com/google/refine/commands/GetPreferenceCommand.java
index cd1681b99..2d133c041 100644
--- a/main/src/com/google/refine/commands/GetPreferenceCommand.java
+++ b/main/src/com/google/refine/commands/GetPreferenceCommand.java
@@ -43,14 +43,19 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 
 import com.google.refine.ProjectManager;
 import com.google.refine.preference.PreferenceStore;
+import com.google.refine.preference.TopList;
 
 public class GetPreferenceCommand extends Command {
     protected static class PreferenceValue  {
         @JsonProperty("value")
-        protected Object pref;
+        protected Object value;
         
-        protected PreferenceValue(Object o) {
-            pref = o;
+        protected PreferenceValue(Object pref) {
+            if (pref == null || pref instanceof String || pref instanceof Number || pref instanceof Boolean || pref instanceof TopList) {
+                value = pref;
+            } else {
+                value = pref.toString();
+            }
         }
     }
     
diff --git a/main/src/com/google/refine/commands/HttpHeadersSupport.java b/main/src/com/google/refine/commands/HttpHeadersSupport.java
index 6bac9db5b..e7cd88b3e 100644
--- a/main/src/com/google/refine/commands/HttpHeadersSupport.java
+++ b/main/src/com/google/refine/commands/HttpHeadersSupport.java
@@ -37,6 +37,9 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 import com.google.refine.RefineServlet;
 
 abstract public class HttpHeadersSupport {
@@ -44,8 +47,11 @@ abstract public class HttpHeadersSupport {
     static final protected Map<String, HttpHeaderInfo> s_headers = new HashMap<String, HttpHeaderInfo>();
 
     static public class HttpHeaderInfo {
+        @JsonIgnore
         final public String                 name;
+        @JsonProperty("header")
         final public String                 header;
+        @JsonProperty("defaultValue")
         final public String                 defaultValue;
         
         HttpHeaderInfo(String header, String defaultValue) {
diff --git a/main/src/com/google/refine/expr/MetaParser.java b/main/src/com/google/refine/expr/MetaParser.java
index 274b8e0f8..03ec48949 100644
--- a/main/src/com/google/refine/expr/MetaParser.java
+++ b/main/src/com/google/refine/expr/MetaParser.java
@@ -39,6 +39,9 @@ import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 import com.google.refine.grel.Parser;
 
 import clojure.lang.IFn;
@@ -47,8 +50,11 @@ import clojure.lang.RT;
 abstract public class MetaParser {
 
     static public class LanguageInfo {
+        @JsonProperty("name")
         final public String                 name;
+        @JsonIgnore
         final public LanguageSpecificParser parser;
+        @JsonProperty("defaultExpression")
         final public String                 defaultExpression;
         
         LanguageInfo(String name, LanguageSpecificParser parser, String defaultExpression) {
diff --git a/main/src/com/google/refine/importing/ImportingJob.java b/main/src/com/google/refine/importing/ImportingJob.java
index 4f52f6c3b..27b0c65e9 100644
--- a/main/src/com/google/refine/importing/ImportingJob.java
+++ b/main/src/com/google/refine/importing/ImportingJob.java
@@ -42,6 +42,9 @@ import org.apache.commons.io.FileUtils;
 import org.json.JSONArray;
 import org.json.JSONObject;
 
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.annotation.JsonRawValue;
+
 import com.google.refine.ProjectManager;
 import com.google.refine.model.Project;
 import com.google.refine.model.metadata.ProjectMetadata;
@@ -77,6 +80,11 @@ public class ImportingJob  {
         dir.mkdirs();
     }
     
+    @JsonProperty("config")
+    @JsonRawValue
+    public String getJsonConfig() {
+        return config.toString();
+    }
     
     public JSONObject getOrCreateDefaultConfig() {
         return config;
diff --git a/main/src/com/google/refine/operations/recon/ReconOperation.java b/main/src/com/google/refine/operations/recon/ReconOperation.java
index 34593b77c..976b1acb3 100644
--- a/main/src/com/google/refine/operations/recon/ReconOperation.java
+++ b/main/src/com/google/refine/operations/recon/ReconOperation.java
@@ -149,9 +149,9 @@ public class ReconOperation extends EngineDependentOperation {
                 "{\n" + 
                 "  \"action\" : \"createFacet\",\n" + 
                 "  \"facetConfig\" : {\n" + 
-                "  \"columnName\" : \"researcher\",\n" + 
+                "  \"columnName\" : \"" + _columnName + "\",\n" + 
                 "  \"expression\" : \"forNonBlank(cell.recon.judgment, v, v, if(isNonBlank(value), \\\"(unreconciled)\\\", \\\"(blank)\\\"))\",\n" + 
-                "    \"name\" : \"researcher: judgment\"\n" + 
+                "    \"name\" : \"" + _columnName + ": judgment\"\n" + 
                 "    },\n" + 
                 "    \"facetOptions\" : {\n" + 
                 "      \"scroll\" : false\n" + 
@@ -162,10 +162,10 @@ public class ReconOperation extends EngineDependentOperation {
                 "{\n" + 
                 "  \"action\" : \"createFacet\",\n" + 
                 "  \"facetConfig\" : {\n" + 
-                "    \"columnName\" : \"researcher\",\n" + 
+                "    \"columnName\" : \"" + _columnName + "\",\n" + 
                 "    \"expression\" : \"cell.recon.best.score\",\n" + 
                 "    \"mode\" : \"range\",\n" + 
-                "    \"name\" : \"researcher: best candidate's score\"\n" + 
+                "    \"name\" : \"" + _columnName + ": best candidate's score\"\n" + 
                 "         },\n" + 
                 "         \"facetType\" : \"range\"\n" + 
                 "}";
diff --git a/main/src/com/google/refine/preference/PreferenceStore.java b/main/src/com/google/refine/preference/PreferenceStore.java
index 3e64a4a77..25a27fba2 100644
--- a/main/src/com/google/refine/preference/PreferenceStore.java
+++ b/main/src/com/google/refine/preference/PreferenceStore.java
@@ -79,7 +79,7 @@ public class PreferenceStore  {
     
     private Object wrapJSONArray(Object value) {
         ObjectMapper mapper = new ObjectMapper();
-        if(value != null && value instanceof JSONArray) {
+        if(value != null && (value instanceof JSONArray || value instanceof JSONObject)) {
             try {
                 return mapper.readValue(value.toString(), JsonNode.class);
             } catch (IOException e) {
diff --git a/main/src/com/google/refine/util/Pool.java b/main/src/com/google/refine/util/Pool.java
index 0ac44ab0e..ddb9ea39e 100644
--- a/main/src/com/google/refine/util/Pool.java
+++ b/main/src/com/google/refine/util/Pool.java
@@ -107,6 +107,7 @@ public class Pool  {
         
         for (Recon recon : recons2) {
             ParsingUtilities.saveWriter.writeValue(writer, recon);
+            writer.write('\n');
         }
     }
     
diff --git a/main/tests/server/src/com/google/refine/tests/browsing/facets/ListFacetTests.java b/main/tests/server/src/com/google/refine/tests/browsing/facets/ListFacetTests.java
index 6a18c1782..92a77bf63 100644
--- a/main/tests/server/src/com/google/refine/tests/browsing/facets/ListFacetTests.java
+++ b/main/tests/server/src/com/google/refine/tests/browsing/facets/ListFacetTests.java
@@ -33,7 +33,7 @@ public class ListFacetTests extends RefineTest {
             + "\"expression\":\"value+\\\"bar\\\"\","
             + "\"columnName\":\"Column A\","
             + "\"invert\":false,"
-            + "\"error\":\"No column named Column A\"}\" are not equal as JSON strings.\n" + 
+            + "\"error\":\"No column named Column A\"" + 
             "}";
     
     private static String jsonFacet = "{"