diff --git a/api.go b/api.go
index 9f7356cb8..f86a1db28 100644
--- a/api.go
+++ b/api.go
@@ -91,14 +91,14 @@ func (api *API) validate(f apiMethod) error {
 // Query parses a PQL query out of the request and executes it.
 func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
 	if err := api.validate(apiQuery); err != nil {
-		return QueryResponse{}, errors.Wrap(err, "validate api method")
+		return QueryResponse{}, errors.Wrap(err, "validating api method")
 	}
 
 	resp := QueryResponse{}
 
 	q, err := pql.NewParser(strings.NewReader(req.Query)).Parse()
 	if err != nil {
-		return resp, err
+		return resp, errors.Wrap(err, "parsing")
 	}
 	execOpts := &ExecOptions{
 		Remote:       req.Remote,
@@ -107,7 +107,7 @@ func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, er
 	}
 	results, err := api.Executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
 	if err != nil {
-		return resp, err
+		return resp, errors.Wrap(err, "executing")
 	}
 	resp.Results = results
 
@@ -126,7 +126,7 @@ func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, er
 		// Retrieve column attributes across all calls.
 		columnAttrSets, err := api.readColumnAttrSets(api.Holder.Index(req.Index), columnIDs)
 		if err != nil {
-			return resp, err
+			return resp, errors.Wrap(err, "reading column attrs")
 		}
 		resp.ColumnAttrSets = columnAttrSets
 	}
@@ -144,7 +144,7 @@ func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet
 		// Read attributes for column. Skip column if empty.
 		attrs, err := index.ColumnAttrStore().Attrs(id)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "getting attrs")
 		} else if len(attrs) == 0 {
 			continue
 		}
@@ -159,13 +159,13 @@ func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet
 // CreateIndex makes a new Pilosa index.
 func (api *API) CreateIndex(ctx context.Context, indexName string, options IndexOptions) (*Index, error) {
 	if err := api.validate(apiCreateIndex); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Create index.
 	index, err := api.Holder.CreateIndex(indexName, options)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "creating index")
 	}
 	// Send the create index message to all nodes.
 	err = api.Broadcaster.SendSync(
@@ -175,7 +175,7 @@ func (api *API) CreateIndex(ctx context.Context, indexName string, options Index
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending CreateIndex message: %s", err)
-		return nil, err
+		return nil, errors.Wrap(err, "sending CreateIndex message")
 	}
 	api.Holder.Stats.Count("createIndex", 1, 1.0)
 	return index, nil
@@ -184,7 +184,7 @@ func (api *API) CreateIndex(ctx context.Context, indexName string, options Index
 // Index retrieves the named index.
 func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 	if err := api.validate(apiIndex); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	index := api.Holder.Index(indexName)
@@ -198,13 +198,13 @@ func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 // nothing and returns no error.
 func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 	if err := api.validate(apiDeleteIndex); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Delete index from the holder.
 	err := api.Holder.DeleteIndex(indexName)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "deleting index")
 	}
 	// Send the delete index message to all nodes.
 	err = api.Broadcaster.SendSync(
@@ -213,7 +213,7 @@ func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending DeleteIndex message: %s", err)
-		return err
+		return errors.Wrap(err, "sending DeleteIndex message")
 	}
 	api.Holder.Stats.Count("deleteIndex", 1, 1.0)
 	return nil
@@ -222,7 +222,7 @@ func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 // CreateFrame makes the named frame in the named index with the given options.
 func (api *API) CreateFrame(ctx context.Context, indexName string, frameName string, options FrameOptions) (*Frame, error) {
 	if err := api.validate(apiCreateFrame); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Find index.
@@ -234,7 +234,7 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 	// Create frame.
 	frame, err := index.CreateFrame(frameName, options)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "creating frame")
 	}
 
 	// Send the create frame message to all nodes.
@@ -246,7 +246,7 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending CreateFrame message: %s", err)
-		return nil, err
+		return nil, errors.Wrap(err, "sending CreateFrame message")
 	}
 	api.Holder.Stats.CountWithCustomTags("createFrame", 1, 1.0, []string{fmt.Sprintf("index:%s", indexName)})
 	return frame, nil
@@ -257,7 +257,7 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 // action is taken.
 func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName string) error {
 	if err := api.validate(apiDeleteFrame); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Find index.
@@ -268,7 +268,7 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 
 	// Delete frame from the index.
 	if err := index.DeleteFrame(frameName); err != nil {
-		return err
+		return errors.Wrap(err, "deleting frame")
 	}
 
 	// Send the delete frame message to all nodes.
@@ -279,7 +279,7 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 		})
 	if err != nil {
 		api.Logger.Printf("problem sending DeleteFrame message: %s", err)
-		return err
+		return errors.Wrap(err, "sending DeleteFrame message")
 	}
 	api.Holder.Stats.CountWithCustomTags("deleteFrame", 1, 1.0, []string{fmt.Sprintf("index:%s", indexName)})
 	return nil
@@ -289,7 +289,7 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 // CSV of the form <row>,<col>
 func (api *API) ExportCSV(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, w io.Writer) error {
 	if err := api.validate(apiExportCSV); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Validate that this handler owns the slice.
@@ -314,7 +314,7 @@ func (api *API) ExportCSV(ctx context.Context, indexName string, frameName strin
 			strconv.FormatUint(columnID, 10),
 		})
 	}); err != nil {
-		return err
+		return errors.Wrap(err, "writing CSV")
 	}
 
 	// Ensure data is flushed.
@@ -326,7 +326,7 @@ func (api *API) ExportCSV(ctx context.Context, indexName string, frameName strin
 // SliceNodes returns the node and all replicas which should contain a slice's data.
 func (api *API) SliceNodes(ctx context.Context, indexName string, slice uint64) ([]*Node, error) {
 	if err := api.validate(apiSliceNodes); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	return api.Cluster.SliceNodes(indexName, slice), nil
@@ -337,7 +337,7 @@ func (api *API) SliceNodes(ctx context.Context, indexName string, slice uint64)
 // the UnmarshalFragment API call.
 func (api *API) MarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) (io.WriterTo, error) {
 	if err := api.validate(apiMarshalFragment); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve fragment from holder.
@@ -353,7 +353,7 @@ func (api *API) MarshalFragment(ctx context.Context, indexName string, frameName
 // fragment's data.
 func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, reader io.ReadCloser) error {
 	if err := api.validate(apiUnmarshalFragment); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame.
@@ -365,18 +365,18 @@ func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameNa
 	// Retrieve view.
 	view, err := f.CreateViewIfNotExists(viewName)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "creating view")
 	}
 
 	// Retrieve fragment from frame.
 	frag, err := view.CreateFragmentIfNotExists(slice)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "creating fragment")
 	}
 
 	// Read fragment in from request body.
 	if _, err := frag.ReadFrom(reader); err != nil {
-		return err
+		return errors.Wrap(err, "reading fragment")
 	}
 	return nil
 }
@@ -386,7 +386,7 @@ func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameNa
 // ids from a "block" which is a subdivision of a fragment.
 func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte, error) {
 	if err := api.validate(apiFragmentBlockData); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	reqBytes, err := ioutil.ReadAll(body)
@@ -419,7 +419,7 @@ func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte,
 // FragmentBlocks returns the checksums and block ids for all blocks in the specified fragment.
 func (api *API) FragmentBlocks(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) ([]FragmentBlock, error) {
 	if err := api.validate(apiFragmentBlocks); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve fragment from holder.
@@ -437,7 +437,7 @@ func (api *API) FragmentBlocks(ctx context.Context, indexName string, frameName
 // from replicas in the cluster and restores that data to it.
 func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName string, host *URI) error {
 	if err := api.validate(apiRestoreFrame); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Create a client for the remote cluster.
@@ -446,7 +446,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	// Determine the maximum number of slices.
 	maxSlices, err := client.MaxSliceByIndex(ctx)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting max slice")
 	}
 
 	// Retrieve frame.
@@ -458,7 +458,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	// Retrieve list of all views.
 	views, err := client.FrameViews(ctx, indexName, frameName)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting views")
 	}
 
 	// Loop over each slice and import it if this node owns it.
@@ -473,19 +473,19 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 			// Create view.
 			v, err := f.CreateViewIfNotExists(view)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "creating view")
 			}
 
 			// Otherwise retrieve the local fragment.
 			frag, err := v.CreateFragmentIfNotExists(slice)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "creating fragment")
 			}
 
 			// Stream backup from remote node.
 			rd, err := client.BackupSlice(ctx, indexName, frameName, view, slice)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "getting backup")
 			} else if rd == nil {
 				continue // slice doesn't exist
 			}
@@ -494,7 +494,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 			if err := func() error {
 				defer rd.Close()
 				if _, err := frag.ReadFrom(rd); err != nil {
-					return err
+					return errors.Wrap(err, "reading fragment")
 				}
 				return nil
 			}(); err != nil {
@@ -515,7 +515,7 @@ func (api *API) Hosts(ctx context.Context) []*Node {
 // CreateInputDefinition is deprecated and will be removed. Do not use it.
 func (api *API) CreateInputDefinition(ctx context.Context, indexName string, inputDefName string, inputDef InputDefinitionInfo) error {
 	if err := api.validate(apiCreateInputDefinition); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf(`CreateInputDefinition is deprecated and will be removed.
@@ -553,7 +553,7 @@ Please open an issue if you need to continue using it.`)
 // InputDefinition is deprecated and will be removed.
 func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefName string) (*InputDefinition, error) {
 	if err := api.validate(apiInputDefinition); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf(`InputDefinition is deprecated and will be removed.`)
@@ -573,7 +573,7 @@ func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefN
 // DeleteInputDefinition is deprecated and will be removed.
 func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inputDefName string) error {
 	if err := api.validate(apiDeleteInputDefinition); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf("DeleteInputDefinition is deprecated and will be removed.")
@@ -602,7 +602,7 @@ func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inp
 // WriteInput is deprecated and will be removed.
 func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName string, reqs []interface{}) error {
 	if err := api.validate(apiWriteInput); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	api.Logger.Printf("WriteInput is deprecated and will be removed.")
@@ -630,7 +630,7 @@ func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName s
 // RecalculateCaches forces all TopN caches to be updated. Used mainly for integration tests.
 func (api *API) RecalculateCaches(ctx context.Context) error {
 	if err := api.validate(apiRecalculateCaches); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	err := api.Broadcaster.SendSync(&internal.RecalculateCaches{})
@@ -645,7 +645,7 @@ func (api *API) RecalculateCaches(ctx context.Context) error {
 // the body and forwards it to the BroadcastHandler.
 func (api *API) ClusterMessage(ctx context.Context, reqBody io.Reader) error {
 	if err := api.validate(apiClusterMessage); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Read entire body.
@@ -681,7 +681,7 @@ func (api *API) Schema(ctx context.Context) []*IndexInfo {
 // CreateField creates a new BSI field in the given index and frame.
 func (api *API) CreateField(ctx context.Context, indexName string, frameName string, field *Field) error {
 	if err := api.validate(apiCreateField); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame by name.
@@ -692,7 +692,7 @@ func (api *API) CreateField(ctx context.Context, indexName string, frameName str
 
 	// Create new field.
 	if err := f.CreateField(field); err != nil {
-		return err
+		return errors.Wrap(err, "creating field")
 	}
 
 	// Send the create field message to all nodes.
@@ -705,13 +705,13 @@ func (api *API) CreateField(ctx context.Context, indexName string, frameName str
 	if err != nil {
 		api.Logger.Printf("problem sending CreateField message: %s", err)
 	}
-	return err
+	return errors.Wrap(err, "sending CreateField message")
 }
 
 // DeleteField deletes the given field.
 func (api *API) DeleteField(ctx context.Context, indexName string, frameName string, fieldName string) error {
 	if err := api.validate(apiDeleteField); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame by name.
@@ -722,7 +722,7 @@ func (api *API) DeleteField(ctx context.Context, indexName string, frameName str
 
 	// Delete field.
 	if err := f.DeleteField(fieldName); err != nil {
-		return err
+		return errors.Wrap(err, "deleting field")
 	}
 
 	// Send the delete field message to all nodes.
@@ -735,13 +735,13 @@ func (api *API) DeleteField(ctx context.Context, indexName string, frameName str
 	if err != nil {
 		api.Logger.Printf("problem sending DeleteField message: %s", err)
 	}
-	return err
+	return errors.Wrap(err, "sending DeleteField message")
 }
 
 // Fields returns the fields in the given frame.
 func (api *API) Fields(ctx context.Context, indexName string, frameName string) ([]*Field, error) {
 	if err := api.validate(apiFields); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	index := api.Holder.index(indexName)
@@ -760,7 +760,7 @@ func (api *API) Fields(ctx context.Context, indexName string, frameName string)
 // Views returns the views in the given frame.
 func (api *API) Views(ctx context.Context, indexName string, frameName string) ([]*View, error) {
 	if err := api.validate(apiViews); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve views.
@@ -777,7 +777,7 @@ func (api *API) Views(ctx context.Context, indexName string, frameName string) (
 // DeleteView removes the given view.
 func (api *API) DeleteView(ctx context.Context, indexName string, frameName string, viewName string) error {
 	if err := api.validate(apiDeleteView); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve frame.
@@ -790,7 +790,7 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 	if err := f.DeleteView(viewName); err != nil {
 		// Ignore this error because views do not exist on all nodes due to slice distribution.
 		if err != ErrInvalidView {
-			return err
+			return errors.Wrap(err, "deleting view")
 		}
 	}
 
@@ -805,13 +805,13 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 		api.Logger.Printf("problem sending DeleteView message: %s", err)
 	}
 
-	return err
+	return errors.Wrap(err, "sending DeleteView message")
 }
 
 // IndexAttrDiff
 func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []AttrBlock) (map[uint64]map[string]interface{}, error) {
 	if err := api.validate(apiIndexAttrDiff); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve index from holder.
@@ -823,7 +823,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 	// Retrieve local blocks.
 	localBlocks, err := index.ColumnAttrStore().Blocks()
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "getting blocks")
 	}
 
 	// Read all attributes from all mismatched blocks.
@@ -832,7 +832,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 		// Retrieve block data.
 		m, err := index.ColumnAttrStore().BlockData(blockID)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "getting block")
 		}
 
 		// Copy to index-wide struct.
@@ -845,7 +845,7 @@ func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []At
 
 func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName string, blocks []AttrBlock) (map[uint64]map[string]interface{}, error) {
 	if err := api.validate(apiFrameAttrDiff); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	// Retrieve index from holder.
@@ -857,7 +857,7 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 	// Retrieve local blocks.
 	localBlocks, err := f.RowAttrStore().Blocks()
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "getting blocks")
 	}
 
 	// Read all attributes from all mismatched blocks.
@@ -866,7 +866,7 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 		// Retrieve block data.
 		m, err := f.RowAttrStore().BlockData(blockID)
 		if err != nil {
-			return nil, err
+			return nil, errors.Wrap(err, "getting block")
 		}
 
 		// Copy to index-wide struct.
@@ -880,12 +880,12 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 // Import bulk imports data into a particular index,frame,slice.
 func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	if err := api.validate(apiImport); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting frame")
 	}
 
 	// Convert timestamps to time.Time.
@@ -903,18 +903,18 @@ func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	if err != nil {
 		api.Logger.Printf("import error: index=%s, frame=%s, slice=%d, bits=%d, err=%s", req.Index, req.Frame, req.Slice, len(req.ColumnIDs), err)
 	}
-	return err
+	return errors.Wrap(err, "importing")
 }
 
 // ImportValue bulk imports values into a particular field.
 func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest) error {
 	if err := api.validate(apiImportValue); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "getting frame")
 	}
 
 	// Import into fragment.
@@ -922,7 +922,7 @@ func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest
 	if err != nil {
 		api.Logger.Printf("import error: index=%s, frame=%s, slice=%d, field=%s, bits=%d, err=%s", req.Index, req.Frame, req.Slice, req.Field, len(req.ColumnIDs), err)
 	}
-	return err
+	return errors.Wrap(err, "importing")
 }
 
 // MaxSlices returns the maximum slice number for each index in a map.
@@ -1050,7 +1050,7 @@ func (api *API) inputJSONDataParser(req map[string]interface{}, index *Index, na
 // SetCoordinator makes a new Node the cluster coordinator.
 func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode *Node, err error) {
 	if err := api.validate(apiSetCoordinator); err != nil {
-		return nil, nil, errors.Wrap(err, "validate api method")
+		return nil, nil, errors.Wrap(err, "validating api method")
 	}
 
 	oldNode = api.Cluster.NodeByID(api.Cluster.Coordinator)
@@ -1080,7 +1080,7 @@ func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode
 // removing the given node.
 func (api *API) RemoveNode(id string) (*Node, error) {
 	if err := api.validate(apiRemoveNode); err != nil {
-		return nil, errors.Wrap(err, "validate api method")
+		return nil, errors.Wrap(err, "validating api method")
 	}
 
 	removeNode := api.Cluster.nodeByID(id)
@@ -1099,7 +1099,7 @@ func (api *API) RemoveNode(id string) (*Node, error) {
 // ResizeAbort stops the current resize job.
 func (api *API) ResizeAbort() error {
 	if err := api.validate(apiResizeAbort); err != nil {
-		return errors.Wrap(err, "validate api method")
+		return errors.Wrap(err, "validating api method")
 	}
 
 	err := api.Cluster.CompleteCurrentJob(ResizeJobStateAborted)
diff --git a/handler_test.go b/handler_test.go
index 4187b3303..9dfb801af 100644
--- a/handler_test.go
+++ b/handler_test.go
@@ -624,7 +624,7 @@ func TestHandler_Query_Err_JSON(t *testing.T) {
 	h.ServeHTTP(w, test.MustNewHTTPRequest("POST", "/index/i/query", strings.NewReader(`Bitmap(id=100)`)))
 	if w.Code != http.StatusBadRequest {
 		t.Fatalf("unexpected status code: %d", w.Code)
-	} else if body := w.Body.String(); body != `{"error":"marker"}`+"\n" {
+	} else if body := w.Body.String(); body != `{"error":"executing: marker"}`+"\n" {
 		t.Fatalf("unexpected body: %q", body)
 	}
 }
@@ -652,7 +652,7 @@ func TestHandler_Query_Err_Protobuf(t *testing.T) {
 	var resp internal.QueryResponse
 	if err := proto.Unmarshal(w.Body.Bytes(), &resp); err != nil {
 		t.Fatal(err)
-	} else if s := resp.Err; s != `marker` {
+	} else if s := resp.Err; s != `executing: marker` {
 		t.Fatalf("unexpected error: %s", s)
 	}
 }
@@ -684,7 +684,7 @@ func TestHandler_Query_ErrParse(t *testing.T) {
 	h.ServeHTTP(w, test.MustNewHTTPRequest("POST", "/index/idx0/query?slices=0,1", strings.NewReader("bad_fn(")))
 	if w.Code != http.StatusBadRequest {
 		t.Fatalf("unexpected status code: %d", w.Code)
-	} else if body := w.Body.String(); body != `{"error":"expected comma, right paren, or identifier, found \"\" occurred at line 1, char 8"}`+"\n" {
+	} else if body := w.Body.String(); body != `{"error":"parsing: expected comma, right paren, or identifier, found \"\" occurred at line 1, char 8"}`+"\n" {
 		t.Fatalf("unexpected body: %s", body)
 	}
 }
@@ -894,7 +894,7 @@ func TestHandler_Frame_AddField(t *testing.T) {
 		)
 		if err != nil {
 			t.Fatal(err)
-		} else if body := MustReadAll(resp.Body); string(body) != `invalid field type`+"\n" {
+		} else if body := MustReadAll(resp.Body); string(body) != `creating field: invalid field type`+"\n" {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
@@ -916,7 +916,7 @@ func TestHandler_Frame_AddField(t *testing.T) {
 		)
 		if err != nil {
 			t.Fatal(err)
-		} else if body := MustReadAll(resp.Body); string(body) != `invalid field range`+"\n" {
+		} else if body := MustReadAll(resp.Body); string(body) != `creating field: invalid field range`+"\n" {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
@@ -940,7 +940,7 @@ func TestHandler_Frame_AddField(t *testing.T) {
 		)
 		if err != nil {
 			t.Fatal(err)
-		} else if body := MustReadAll(resp.Body); string(body) != `field already exists`+"\n" {
+		} else if body := MustReadAll(resp.Body); string(body) != `creating field: field already exists`+"\n" {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
@@ -1006,7 +1006,7 @@ func TestHandler_Frame_DeleteField(t *testing.T) {
 			t.Fatal(err)
 		} else if body, err := ioutil.ReadAll(resp.Body); err != nil {
 			t.Fatal(err)
-		} else if strings.TrimSpace(string(body)) != `field not found` {
+		} else if strings.TrimSpace(string(body)) != `deleting field: field not found` {
 			t.Fatalf("unexpected body: %q", body)
 		} else if err := resp.Body.Close(); err != nil {
 			t.Fatal(err)
diff --git a/server/server_test.go b/server/server_test.go
index 75e0e2242..b78e8b79f 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -52,10 +52,10 @@ func TestMain_Set_Quick(t *testing.T) {
 
 		// Execute SetBit() commands.
 		for _, cmd := range cmds {
-			if err := client.CreateIndex(context.Background(), "i", pilosa.IndexOptions{}); err != nil && err != pilosa.ErrIndexExists {
+			if err := client.CreateIndex(context.Background(), "i", pilosa.IndexOptions{}); err != nil && !strings.Contains(err.Error(), "index already exists") {
 				t.Fatal(err)
 			}
-			if err := client.CreateFrame(context.Background(), "i", cmd.Frame, pilosa.FrameOptions{}); err != nil && err != pilosa.ErrFrameExists {
+			if err := client.CreateFrame(context.Background(), "i", cmd.Frame, pilosa.FrameOptions{}); err != nil && !strings.Contains(err.Error(), "frame already exists") {
 				t.Fatal(err)
 			}
 			if _, err := m.Query("i", "", fmt.Sprintf(`SetBit(row=%d, frame=%q, col=%d)`, cmd.ID, cmd.Frame, cmd.ColumnID)); err != nil {