diff --git a/api.go b/api.go
index 82ab3a4ce..f57d159f2 100644
--- a/api.go
+++ b/api.go
@@ -19,6 +19,7 @@ import (
 	"encoding/csv"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"reflect"
 	"strconv"
@@ -31,6 +32,8 @@ import (
 	"github.com/pkg/errors"
 )
 
+// API provides the top level programmatic interface to Pilosa. It is usually
+// wrapped by a handler which provides an external interface (e.g. HTTP).
 type API struct {
 	Holder *Holder
 	// The execution engine for running queries.
@@ -46,6 +49,7 @@ type API struct {
 	Logger           Logger
 }
 
+// NewAPI returns a new API instance.
 func NewAPI() *API {
 	return &API{
 		Broadcaster: NopBroadcaster,
@@ -55,7 +59,8 @@ func NewAPI() *API {
 	}
 }
 
-func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
+// Query parses a PQL query out of the request and executes it.
+func (api *API) Query(ctx context.Context, req *QueryRequest) (QueryResponse, error) {
 	resp := QueryResponse{}
 
 	q, err := pql.NewParser(strings.NewReader(req.Query)).Parse()
@@ -67,7 +72,7 @@ func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryRespons
 		ExcludeAttrs: req.ExcludeAttrs,
 		ExcludeBits:  req.ExcludeBits,
 	}
-	results, err := a.Executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
+	results, err := api.Executor.Execute(ctx, req.Index, q, req.Slices, execOpts)
 	if err != nil {
 		return resp, err
 	}
@@ -86,7 +91,7 @@ func (a *API) ExecuteQuery(ctx context.Context, req *QueryRequest) (QueryRespons
 		}
 
 		// Retrieve column attributes across all calls.
-		columnAttrSets, err := a.readColumnAttrSets(a.Holder.Index(req.Index), columnIDs)
+		columnAttrSets, err := api.readColumnAttrSets(api.Holder.Index(req.Index), columnIDs)
 		if err != nil {
 			return resp, err
 		}
@@ -118,6 +123,7 @@ func (api *API) readColumnAttrSets(index *Index, ids []uint64) ([]*ColumnAttrSet
 	return ax, nil
 }
 
+// CreateIndex makes a new Pilosa index.
 func (api *API) CreateIndex(ctx context.Context, indexName string, options IndexOptions) (*Index, error) {
 	// Create index.
 	index, err := api.Holder.CreateIndex(indexName, options)
@@ -138,7 +144,8 @@ func (api *API) CreateIndex(ctx context.Context, indexName string, options Index
 	return index, nil
 }
 
-func (api *API) ReadIndex(ctx context.Context, indexName string) (*Index, error) {
+// Index retrieves the named index.
+func (api *API) Index(ctx context.Context, indexName string) (*Index, error) {
 	index := api.Holder.Index(indexName)
 	if index == nil {
 		return nil, ErrIndexNotFound
@@ -146,6 +153,8 @@ func (api *API) ReadIndex(ctx context.Context, indexName string) (*Index, error)
 	return index, nil
 }
 
+// DeleteIndex removes the named index. If the index is not found it does
+// nothing and returns no error.
 func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 	// Delete index from the holder.
 	err := api.Holder.DeleteIndex(indexName)
@@ -165,6 +174,7 @@ func (api *API) DeleteIndex(ctx context.Context, indexName string) error {
 	return nil
 }
 
+// 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) {
 	// Find index.
 	index := api.Holder.Index(indexName)
@@ -193,6 +203,9 @@ func (api *API) CreateFrame(ctx context.Context, indexName string, frameName str
 	return frame, nil
 }
 
+// DeleteFrame removes the named frame from the named index. If the index is not
+// found, an error is returned. If the frame is not found, it is ignored and no
+// action is taken.
 func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName string) error {
 	// Find index.
 	index := api.Holder.Index(indexName)
@@ -219,9 +232,11 @@ func (api *API) DeleteFrame(ctx context.Context, indexName string, frameName str
 	return nil
 }
 
+// ExportCSV encodes the fragment designated by the index,frame,view,slice as
+// 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 {
 	// Validate that this handler owns the slice.
-	if !api.Cluster.OwnsFragment(api.LocalID(), indexName, slice) {
+	if !api.Cluster.OwnsSlice(api.LocalID(), indexName, slice) {
 		api.Logger.Printf("host does not own slice %s-%s slice:%d", api.URI, indexName, slice)
 		return ErrClusterDoesNotOwnSlice
 	}
@@ -251,11 +266,20 @@ func (api *API) ExportCSV(ctx context.Context, indexName string, frameName strin
 	return nil
 }
 
-func (api *API) FragmentNodes(ctx context.Context, indexName string, slice uint64) []*Node {
-	return api.Cluster.FragmentNodes(indexName, slice)
+// 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 {
+	return api.Cluster.SliceNodes(indexName, slice)
 }
 
-func (api *API) FragmentData(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) (*Fragment, error) {
+// WriterTo is an interface for any Object which knows how to serialize itself to an io.Writer
+type WriterTo interface {
+	WriteTo(w io.Writer) (n int64, err error)
+}
+
+// MarshalFragment returns an object which can write the specified fragment's data
+// to an io.Writer. The serialized data can be read back into a fragment with
+// the UnmarshalFragment API call.
+func (api *API) MarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64) (WriterTo, error) {
 	// Retrieve fragment from holder.
 	f := api.Holder.Fragment(indexName, frameName, viewName, slice)
 	if f == nil {
@@ -264,7 +288,10 @@ func (api *API) FragmentData(ctx context.Context, indexName string, frameName st
 	return f, nil
 }
 
-func (api *API) WriteFragmentData(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, reader io.ReadCloser) error {
+// UnmarshalFragment creates a new fragment (if necessary) and reads data from a
+// Reader which was previously written by MarshalFragment to populate the
+// fragment's data.
+func (api *API) UnmarshalFragment(ctx context.Context, indexName string, frameName string, viewName string, slice uint64, reader io.ReadCloser) error {
 	// Retrieve frame.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@@ -290,19 +317,38 @@ func (api *API) WriteFragmentData(ctx context.Context, indexName string, frameNa
 	return nil
 }
 
-func (api *API) FragmentBlockData(ctx context.Context, req internal.BlockDataRequest) (internal.BlockDataResponse, error) {
+// FragmentBlockData is an endpoint for internal usage. It is not guaranteed to
+// return anything useful. Currently it returns protobuf encoded row and column
+// ids from a "block" which is a subdivision of a fragment.
+func (api *API) FragmentBlockData(ctx context.Context, body io.Reader) ([]byte, error) {
+	reqBytes, err := ioutil.ReadAll(body)
+	if err != nil {
+		return nil, BadRequestError{errors.Wrap(err, "read body error")}
+	}
+	var req internal.BlockDataRequest
+	if err := proto.Unmarshal(reqBytes, &req); err != nil {
+		return nil, BadRequestError{errors.Wrap(err, "unmarshal body error")}
+	}
+
 	// Retrieve fragment from holder.
 	f := api.Holder.Fragment(req.Index, req.Frame, req.View, req.Slice)
 	if f == nil {
-		return internal.BlockDataResponse{}, ErrFragmentNotFound
+		return nil, ErrFragmentNotFound
 	}
 
-	// Read data
-	var resp internal.BlockDataResponse
+	var resp = internal.BlockDataResponse{}
 	resp.RowIDs, resp.ColumnIDs = f.BlockData(int(req.Block))
-	return resp, nil
+
+	// Encode response.
+	buf, err := proto.Marshal(&resp)
+	if err != nil {
+		return nil, errors.Wrap(err, "merge block response encoding error: %s")
+	}
+
+	return buf, nil
 }
 
+// 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) {
 	// Retrieve fragment from holder.
 	f := api.Holder.Fragment(indexName, frameName, viewName, slice)
@@ -315,6 +361,8 @@ func (api *API) FragmentBlocks(ctx context.Context, indexName string, frameName
 	return blocks, nil
 }
 
+// RestoreFrame reads all the data that this host should have for a given frame
+// 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 {
 	// Create a client for the remote cluster.
 	client := NewInternalHTTPClientFromURI(host, api.RemoteClient)
@@ -340,7 +388,7 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	// Loop over each slice and import it if this node owns it.
 	for slice := uint64(0); slice <= maxSlices[indexName]; slice++ {
 		// Ignore this slice if we don't own it.
-		if !api.Cluster.OwnsFragment(api.LocalID(), indexName, slice) {
+		if !api.Cluster.OwnsSlice(api.LocalID(), indexName, slice) {
 			continue
 		}
 
@@ -382,11 +430,16 @@ func (api *API) RestoreFrame(ctx context.Context, indexName string, frameName st
 	return nil
 }
 
-func (api *API) ClusterHosts(ctx context.Context) []*Node {
+// Hosts returns a list of the hosts in the cluster including their ID,
+// URL, and which is the coordinator.
+func (api *API) Hosts(ctx context.Context) []*Node {
 	return api.Cluster.Nodes
 }
 
+// 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 {
+	api.Logger.Printf(`CreateInputDefinition is deprecated and will be removed.
+Please open an issue if you need to continue using it.`)
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@@ -417,7 +470,9 @@ func (api *API) CreateInputDefinition(ctx context.Context, indexName string, inp
 	return nil
 }
 
+// InputDefinition is deprecated and will be removed.
 func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefName string) (*InputDefinition, error) {
+	api.Logger.Printf(`InputDefinition is deprecated and will be removed.`)
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@@ -431,7 +486,9 @@ func (api *API) InputDefinition(ctx context.Context, indexName string, inputDefN
 	return inputDef, nil
 }
 
+// DeleteInputDefinition is deprecated and will be removed.
 func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inputDefName string) error {
+	api.Logger.Printf("DeleteInputDefinition is deprecated and will be removed.")
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@@ -454,7 +511,9 @@ func (api *API) DeleteInputDefinition(ctx context.Context, indexName string, inp
 	return nil
 }
 
+// WriteInput is deprecated and will be removed.
 func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName string, reqs []interface{}) error {
+	api.Logger.Printf("WriteInput is deprecated and will be removed.")
 	// Find index.
 	index := api.Holder.Index(indexName)
 	if index == nil {
@@ -476,6 +535,7 @@ func (api *API) WriteInput(ctx context.Context, indexName string, inputDefName s
 	return nil
 }
 
+// RecalculateCaches forces all TopN caches to be updated. Used mainly for integration tests.
 func (api *API) RecalculateCaches(ctx context.Context) error {
 	err := api.Broadcaster.SendSync(&internal.RecalculateCaches{})
 	if err != nil {
@@ -485,27 +545,41 @@ func (api *API) RecalculateCaches(ctx context.Context) error {
 	return nil
 }
 
-func (api *API) PostClusterMessage(ctx context.Context, pb proto.Message) error {
+// PostClusterMessage is for internal use. It decodes a protobuf message out of
+// the body and forwards it to the BroadcastHandler.
+func (api *API) PostClusterMessage(ctx context.Context, reqBody io.Reader) error {
+	// Read entire body.
+	body, err := ioutil.ReadAll(reqBody)
+	if err != nil {
+		return errors.Wrap(err, "reading body")
+	}
+
+	// Marshal into request object.
+	pb, err := UnmarshalMessage(body)
+	if err != nil {
+		return errors.Wrap(err, "unmarshaling message")
+	}
+
 	// Forward the error message.
 	if err := api.BroadcastHandler.ReceiveMessage(pb); err != nil {
-		return err
+		return errors.Wrap(err, "receiving message")
 	}
 	return nil
 }
 
+// LocalID returns the current node's ID.
 func (api *API) LocalID() string {
 	return api.Cluster.Node.ID
 }
 
+// Schema returns information about each index in Pilosa including which frames
+// and views they contain.
 func (api *API) Schema(ctx context.Context) []*IndexInfo {
 	return api.Holder.Schema()
 }
 
-func (api *API) Status(ctx context.Context) (proto.Message, error) {
-	return api.StatusHandler.ClusterStatus()
-}
-
-func (api *API) CreateFrameField(ctx context.Context, indexName string, frameName string, field *Field) error {
+// 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 {
 	// Retrieve frame by name.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@@ -530,7 +604,8 @@ func (api *API) CreateFrameField(ctx context.Context, indexName string, frameNam
 	return err
 }
 
-func (api *API) DeleteFrameField(ctx context.Context, indexName string, frameName string, fieldName string) error {
+// DeleteField deletes the given field.
+func (api *API) DeleteField(ctx context.Context, indexName string, frameName string, fieldName string) error {
 	// Retrieve frame by name.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@@ -555,7 +630,8 @@ func (api *API) DeleteFrameField(ctx context.Context, indexName string, frameNam
 	return err
 }
 
-func (api *API) FrameFields(ctx context.Context, indexName string, frameName string) ([]*Field, error) {
+// Fields returns the fields in the given frame.
+func (api *API) Fields(ctx context.Context, indexName string, frameName string) ([]*Field, error) {
 	index := api.Holder.index(indexName)
 	if index == nil {
 		return nil, ErrIndexNotFound
@@ -569,7 +645,8 @@ func (api *API) FrameFields(ctx context.Context, indexName string, frameName str
 	return frame.GetFields()
 }
 
-func (api *API) FrameViews(ctx context.Context, indexName string, frameName string) ([]*View, error) {
+// Views returns the views in the given frame.
+func (api *API) Views(ctx context.Context, indexName string, frameName string) ([]*View, error) {
 	// Retrieve views.
 	f := api.Holder.Frame(indexName, frameName)
 	if f == nil {
@@ -581,6 +658,7 @@ func (api *API) FrameViews(ctx context.Context, indexName string, frameName stri
 	return views, nil
 }
 
+// DeleteView removes the given view.
 func (api *API) DeleteView(ctx context.Context, indexName string, frameName string, viewName string) error {
 	// Retrieve frame.
 	f := api.Holder.Frame(indexName, frameName)
@@ -590,7 +668,7 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 
 	// Delete the view.
 	if err := f.DeleteView(viewName); err != nil {
-		// Ingore this error becuase views do not exist on all nodes due to slice distribution.
+		// Ignore this error becuase views do not exist on all nodes due to slice distribution.
 		if err != ErrInvalidView {
 			return err
 		}
@@ -610,6 +688,7 @@ func (api *API) DeleteView(ctx context.Context, indexName string, frameName stri
 	return err
 }
 
+// IndexAttrDiff
 func (api *API) IndexAttrDiff(ctx context.Context, indexName string, blocks []AttrBlock) (map[uint64]map[string]interface{}, error) {
 	// Retrieve index from holder.
 	index := api.Holder.Index(indexName)
@@ -670,6 +749,7 @@ func (api *API) FrameAttrDiff(ctx context.Context, indexName string, frameName s
 	return attrs, nil
 }
 
+// Import bulk imports data into a particular index,frame,slice.
 func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
@@ -694,6 +774,7 @@ func (api *API) Import(ctx context.Context, req internal.ImportRequest) error {
 	return err
 }
 
+// ImportValue bulk imports values into a particular field.
 func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest) error {
 	_, frame, err := api.indexFrame(req.Index, req.Frame, req.Slice)
 	if err != nil {
@@ -708,6 +789,7 @@ func (api *API) ImportValue(ctx context.Context, req internal.ImportValueRequest
 	return err
 }
 
+// ModifyIndexTimeQuantum changes the default time quantum on the given index.
 func (api *API) ModifyIndexTimeQuantum(ctx context.Context, indexName string, timeQuantum TimeQuantum) error {
 	// Retrieve index by name.
 	index := api.Holder.Index(indexName)
@@ -719,6 +801,8 @@ func (api *API) ModifyIndexTimeQuantum(ctx context.Context, indexName string, ti
 	return index.SetTimeQuantum(timeQuantum)
 }
 
+// ModifyFrameTimeQuantum changes the time quantum on the given frame. TODO:
+// what happens if there is already data in the frame?
 func (api *API) ModifyFrameTimeQuantum(ctx context.Context, indexName string, frameName string, timeQuantum TimeQuantum) error {
 	// Retrieve index by name.
 	frame := api.Holder.Frame(indexName, frameName)
@@ -730,14 +814,19 @@ func (api *API) ModifyFrameTimeQuantum(ctx context.Context, indexName string, fr
 	return frame.SetTimeQuantum(timeQuantum)
 }
 
+// MaxSlices returns the maximum slice number for each index in a map.
 func (api *API) MaxSlices(ctx context.Context) map[string]uint64 {
 	return api.Holder.MaxSlices()
 }
 
+// MaxInverseSlices returns the maximum inverse slice number for each index in a
+// map.
 func (api *API) MaxInverseSlices(ctx context.Context) map[string]uint64 {
 	return api.Holder.MaxInverseSlices()
 }
 
+// StatsWithTags returns an instance of whatever implementation of StatsClient
+// pilosa is using with the given tags.
 func (api *API) StatsWithTags(tags []string) StatsClient {
 	if api.Holder == nil || api.Cluster == nil {
 		return nil
@@ -745,7 +834,9 @@ func (api *API) StatsWithTags(tags []string) StatsClient {
 	return api.Holder.Stats.WithTags(tags...)
 }
 
-func (api *API) ClusterLongQueryTime() time.Duration {
+// LongQueryTime returns the configured threshold for logging/statting
+// long running queries.
+func (api *API) LongQueryTime() time.Duration {
 	if api.Cluster == nil {
 		return 0
 	}
@@ -754,7 +845,7 @@ func (api *API) ClusterLongQueryTime() time.Duration {
 
 func (api *API) indexFrame(indexName string, frameName string, slice uint64) (*Index, *Frame, error) {
 	// Validate that this handler owns the slice.
-	if !api.Cluster.OwnsFragment(api.LocalID(), indexName, slice) {
+	if !api.Cluster.OwnsSlice(api.LocalID(), indexName, slice) {
 		api.Logger.Printf("host does not own slice %s-%s slice:%d", api.URI, indexName, slice)
 		return nil, nil, ErrClusterDoesNotOwnSlice
 	}
@@ -776,7 +867,7 @@ func (api *API) indexFrame(indexName string, frameName string, slice uint64) (*I
 	return index, frame, nil
 }
 
-// inputJSONDataParser validates input json file and executes SetBit.
+// inputJSONDataParser validates input json file and executes SetBit. Deprecated - remove with input definition stuff.
 func (api *API) inputJSONDataParser(req map[string]interface{}, index *Index, name string) (map[string][]*Bit, error) {
 	inputDef, err := index.InputDefinition(name)
 	if err != nil {
@@ -845,6 +936,7 @@ func (api *API) inputJSONDataParser(req map[string]interface{}, index *Index, na
 	return setBits, nil
 }
 
+// SetCoordinator makes a new Node the cluster coordinator.
 func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode *Node, err error) {
 	oldNode = api.Cluster.nodeByID(api.Cluster.Coordinator)
 	newNode = api.Cluster.nodeByID(id)
@@ -869,6 +961,8 @@ func (api *API) SetCoordinator(ctx context.Context, id string) (oldNode, newNode
 	return oldNode, newNode, nil
 }
 
+// RemoveNode puts the cluster into the "RESIZING" state and begins the job of
+// removing the given node.
 func (api *API) RemoveNode(id string) (*Node, error) {
 	removeNode := api.Cluster.nodeByID(id)
 	if removeNode == nil {
@@ -883,6 +977,7 @@ func (api *API) RemoveNode(id string) (*Node, error) {
 	return removeNode, nil
 }
 
+// ResizeAbort stops the current resize job.
 func (api *API) ResizeAbort() error {
 	if !api.Cluster.IsCoordinator() {
 		return ErrNodeNotCoordinator
@@ -891,6 +986,14 @@ func (api *API) ResizeAbort() error {
 	return errors.Wrap(err, "complete current job")
 }
 
+// State returns the cluster state which is usually "NORMAL", but could be
+// "STARTING", "RESIZING", or potentially others. See cluster.go for more
+// details.
 func (api *API) State() string {
 	return api.Cluster.State()
 }
+
+// Version returns the Pilosa version.
+func (api *API) Version() string {
+	return strings.TrimPrefix(Version, "v")
+}
diff --git a/cluster.go b/cluster.go
index c490c58cb..abf753892 100644
--- a/cluster.go
+++ b/cluster.go
@@ -654,7 +654,7 @@ func (c *Cluster) fragsByHost(idx *Index) fragsByHost {
 func (c *Cluster) fragCombos(idx string, maxSlice uint64, frameViews viewsByFrame) fragsByHost {
 	t := make(fragsByHost)
 	for i := uint64(0); i <= maxSlice; i++ {
-		nodes := c.FragmentNodes(idx, i)
+		nodes := c.SliceNodes(idx, i)
 		for _, n := range nodes {
 			// for each frame/view combination:
 			for frame, views := range frameViews {
@@ -807,14 +807,14 @@ func (c *Cluster) Partition(index string, slice uint64) int {
 	return int(h.Sum64() % uint64(c.PartitionN))
 }
 
-// FragmentNodes returns a list of nodes that own a fragment.
-func (c *Cluster) FragmentNodes(index string, slice uint64) []*Node {
+// SliceNodes returns a list of nodes that own a fragment.
+func (c *Cluster) SliceNodes(index string, slice uint64) []*Node {
 	return c.PartitionNodes(c.Partition(index, slice))
 }
 
-// OwnsFragment returns true if a host owns a fragment.
-func (c *Cluster) OwnsFragment(nodeID string, index string, slice uint64) bool {
-	return Nodes(c.FragmentNodes(index, slice)).ContainsID(nodeID)
+// OwnsSlice returns true if a host owns a fragment.
+func (c *Cluster) OwnsSlice(nodeID string, index string, slice uint64) bool {
+	return Nodes(c.SliceNodes(index, slice)).ContainsID(nodeID)
 }
 
 // PartitionNodes returns a list of nodes that own a partition.
diff --git a/executor.go b/executor.go
index e74cd63ba..b7108e9e0 100644
--- a/executor.go
+++ b/executor.go
@@ -941,7 +941,7 @@ func (e *Executor) executeClearBit(ctx context.Context, index string, c *pql.Cal
 func (e *Executor) executeClearBitView(ctx context.Context, index string, c *pql.Call, f *Frame, view string, colID, rowID uint64, opt *ExecOptions) (bool, error) {
 	slice := colID / SliceWidth
 	ret := false
-	for _, node := range e.Cluster.FragmentNodes(index, slice) {
+	for _, node := range e.Cluster.SliceNodes(index, slice) {
 		// Update locally if host matches.
 		if node.ID == e.Node.ID {
 			val, err := f.ClearBit(view, rowID, colID, nil)
@@ -1042,7 +1042,7 @@ func (e *Executor) executeSetBitView(ctx context.Context, index string, c *pql.C
 	slice := colID / SliceWidth
 	ret := false
 
-	for _, node := range e.Cluster.FragmentNodes(index, slice) {
+	for _, node := range e.Cluster.SliceNodes(index, slice) {
 		// Update locally if host matches.
 		if node.ID == e.Node.ID {
 			val, err := f.SetBit(view, rowID, colID, timestamp)
@@ -1385,7 +1385,7 @@ func (e *Executor) slicesByNode(nodes []*Node, index string, slices []uint64) (m
 
 loop:
 	for _, slice := range slices {
-		for _, node := range e.Cluster.FragmentNodes(index, slice) {
+		for _, node := range e.Cluster.SliceNodes(index, slice) {
 			if Nodes(nodes).Contains(node) {
 				m[node] = append(m[node], slice)
 				continue loop
diff --git a/fragment.go b/fragment.go
index 438a80ae7..c44a07380 100644
--- a/fragment.go
+++ b/fragment.go
@@ -1702,7 +1702,7 @@ func (s *FragmentSyncer) isClosing() bool {
 // then merges any blocks which have differences.
 func (s *FragmentSyncer) SyncFragment() error {
 	// Determine replica set.
-	nodes := s.Cluster.FragmentNodes(s.Fragment.Index(), s.Fragment.Slice())
+	nodes := s.Cluster.SliceNodes(s.Fragment.Index(), s.Fragment.Slice())
 	if len(nodes) == 1 {
 		return nil
 	}
@@ -1784,7 +1784,7 @@ func (s *FragmentSyncer) syncBlock(id int) error {
 	// Read pairs from each remote block.
 	var pairSets []PairSet
 	var clients []InternalClient
-	for _, node := range s.Cluster.FragmentNodes(f.Index(), f.Slice()) {
+	for _, node := range s.Cluster.SliceNodes(f.Index(), f.Slice()) {
 		if s.Node.ID == node.ID {
 			continue
 		}
diff --git a/handler.go b/handler.go
index d7536f738..33d2e5846 100644
--- a/handler.go
+++ b/handler.go
@@ -108,14 +108,14 @@ func BuildRouters(handler *Handler) {
 
 func (h *Handler) populateValidators() {
 	h.validators = map[string]*queryValidationSpec{}
-	h.validators["GetFragmentNodes"] = QueryValidationSpecRequired("slice").Optional("index")
-	h.validators["GetSliceMax"] = QueryValidationSpecRequired().Optional("inverse")
-	h.validators["PostQuery"] = QueryValidationSpecRequired().Optional("slices", "columnAttrs", "excludeAttrs", "excludeBits")
-	h.validators["GetExport"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["GetFragmentData"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["PostFragmentData"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["GetFragmentBlocks"] = QueryValidationSpecRequired("index", "frame", "view", "slice")
-	h.validators["PostFrameRestore"] = QueryValidationSpecRequired("host")
+	h.validators["GetFragmentNodes"] = queryValidationSpecRequired("slice").Optional("index")
+	h.validators["GetSliceMax"] = queryValidationSpecRequired().Optional("inverse")
+	h.validators["PostQuery"] = queryValidationSpecRequired().Optional("slices", "columnAttrs", "excludeAttrs", "excludeBits")
+	h.validators["GetExport"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["GetFragmentData"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["PostFragmentData"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["GetFragmentBlocks"] = queryValidationSpecRequired("index", "frame", "view", "slice")
+	h.validators["PostFrameRestore"] = queryValidationSpecRequired("host")
 }
 
 func (h *Handler) queryArgValidator(next http.Handler) http.Handler {
@@ -154,7 +154,7 @@ func loadCommon(router *mux.Router, handler *Handler) {
 	router.HandleFunc("/cluster/message", handler.handlePostClusterMessage).Methods("POST")
 	router.HandleFunc("/cluster/resize/set-coordinator", handler.handlePostClusterResizeSetCoordinator).Methods("POST")
 	router.PathPrefix("/debug/pprof/").Handler(http.DefaultServeMux).Methods("GET")
-	router.HandleFunc("/debug/vars", handler.handleExpvar).Methods("GET")
+	router.Handle("/debug/vars", expvar.Handler()).Methods("GET")
 	router.HandleFunc("/fragment/data", handler.handleGetFragmentData).Methods("GET").Name("GetFragmentData")
 	router.HandleFunc("/hosts", handler.handleGetHosts).Methods("GET")
 	router.HandleFunc("/id", handler.handleGetID).Methods("GET")
@@ -174,7 +174,7 @@ func loadRestricted(router *mux.Router, handler *Handler) {
 func loadNormal(router *mux.Router, handler *Handler) {
 	router.HandleFunc("/cluster/resize/remove-node", handler.handlePostClusterResizeRemoveNode).Methods("POST")
 	router.PathPrefix("/debug/pprof/").Handler(http.DefaultServeMux).Methods("GET")
-	router.HandleFunc("/debug/vars", handler.handleExpvar).Methods("GET")
+	router.Handle("/debug/vars", expvar.Handler()).Methods("GET")
 	router.HandleFunc("/export", handler.handleGetExport).Methods("GET").Name("GetExport")
 	router.HandleFunc("/fragment/block/data", handler.handleGetFragmentBlockData).Methods("GET")
 	router.HandleFunc("/fragment/blocks", handler.handleGetFragmentBlocks).Methods("GET").Name("GetFragmentBlocks")
@@ -241,7 +241,7 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// Calculate per request StatsD metrics when the handler is fully configured.
 	statsTags := make([]string, 0, 3)
 
-	longQueryTime := h.API.ClusterLongQueryTime()
+	longQueryTime := h.API.LongQueryTime()
 	if longQueryTime > 0 && dif > longQueryTime {
 		h.Logger.Printf("%s %s %v", r.Method, r.URL.String(), dif)
 		statsTags = append(statsTags, "slow_query")
@@ -270,7 +270,7 @@ func (h *Handler) handleWebUI(w http.ResponseWriter, r *http.Request) {
 	}
 	filesystem, err := h.FileSystem.New()
 	if err != nil {
-		h.writeQueryResponse(w, r, &QueryResponse{Err: err})
+		_ = h.writeQueryResponse(w, r, &QueryResponse{Err: err})
 		h.Logger.Printf("Pilosa WebUI is not available. Please run `make generate-statik` before building Pilosa with `make install`.")
 		return
 	}
@@ -289,20 +289,11 @@ func (h *Handler) handleGetSchema(w http.ResponseWriter, r *http.Request) {
 
 // handleGetStatus handles GET /status requests.
 func (h *Handler) handleGetStatus(w http.ResponseWriter, r *http.Request) {
-	pb, err := h.API.Status(r.Context())
-	if err != nil {
-		h.Logger.Printf("cluster status error: %s", err)
-		return
+	status := getStatusResponse{
+		State: h.API.State(),
+		Nodes: h.API.Hosts(r.Context()),
 	}
-
-	cs, ok := pb.(*internal.ClusterStatus)
-	if !ok {
-		panic("status is not a status")
-	}
-	if err := json.NewEncoder(w).Encode(getStatusResponse{
-		State: cs.State,
-		Nodes: DecodeNodes(cs.Nodes),
-	}); err != nil {
+	if err := json.NewEncoder(w).Encode(status); err != nil {
 		h.Logger.Printf("write status response error: %s", err)
 	}
 }
@@ -328,7 +319,7 @@ func (h *Handler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
 	// TODO: Remove
 	req.Index = mux.Vars(r)["index"]
 
-	resp, err := h.API.ExecuteQuery(r.Context(), req)
+	resp, err := h.API.Query(r.Context(), req)
 	if err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		h.writeQueryResponse(w, r, &QueryResponse{Err: err})
@@ -374,7 +365,7 @@ func (h *Handler) handleGetIndexes(w http.ResponseWriter, r *http.Request) {
 // handleGetIndex handles GET /index/<indexname> requests.
 func (h *Handler) handleGetIndex(w http.ResponseWriter, r *http.Request) {
 	indexName := mux.Vars(r)["index"]
-	index, err := h.API.ReadIndex(r.Context(), indexName)
+	index, err := h.API.Index(r.Context(), indexName)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusNotFound)
 		return
@@ -742,7 +733,7 @@ func (h *Handler) handlePostFrameField(w http.ResponseWriter, r *http.Request) {
 		Max:  req.Max,
 	}
 
-	if err := h.API.CreateFrameField(r.Context(), indexName, frameName, field); err != nil {
+	if err := h.API.CreateField(r.Context(), indexName, frameName, field); err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
 		} else {
@@ -771,7 +762,7 @@ func (h *Handler) handleDeleteFrameField(w http.ResponseWriter, r *http.Request)
 	frameName := mux.Vars(r)["frame"]
 	fieldName := mux.Vars(r)["field"]
 
-	if err := h.API.DeleteFrameField(r.Context(), indexName, frameName, fieldName); err != nil {
+	if err := h.API.DeleteField(r.Context(), indexName, frameName, fieldName); err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
 		} else {
@@ -790,7 +781,7 @@ func (h *Handler) handleGetFrameFields(w http.ResponseWriter, r *http.Request) {
 	indexName := mux.Vars(r)["index"]
 	frameName := mux.Vars(r)["frame"]
 
-	fields, err := h.API.FrameFields(r.Context(), indexName, frameName)
+	fields, err := h.API.Fields(r.Context(), indexName, frameName)
 	if err != nil {
 		switch err {
 		case ErrIndexNotFound:
@@ -824,7 +815,7 @@ func (h *Handler) handleGetFrameViews(w http.ResponseWriter, r *http.Request) {
 	indexName := mux.Vars(r)["index"]
 	frameName := mux.Vars(r)["frame"]
 
-	views, err := h.API.FrameViews(r.Context(), indexName, frameName)
+	views, err := h.API.Views(r.Context(), indexName, frameName)
 	if err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
@@ -1178,7 +1169,7 @@ func (h *Handler) handleGetFragmentNodes(w http.ResponseWriter, r *http.Request)
 	}
 
 	// Retrieve fragment owner nodes.
-	nodes := h.API.FragmentNodes(r.Context(), index, slice)
+	nodes := h.API.SliceNodes(r.Context(), index, slice)
 
 	// Write to response.
 	if err := json.NewEncoder(w).Encode(nodes); err != nil {
@@ -1197,7 +1188,7 @@ func (h *Handler) handleGetFragmentData(w http.ResponseWriter, r *http.Request)
 	}
 
 	// Retrieve fragment from holder.
-	f, err := h.API.FragmentData(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice)
+	f, err := h.API.MarshalFragment(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice)
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusNotFound)
 		return
@@ -1219,7 +1210,7 @@ func (h *Handler) handlePostFragmentData(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	if err = h.API.WriteFragmentData(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice, r.Body); err != nil {
+	if err = h.API.UnmarshalFragment(r.Context(), q.Get("index"), q.Get("frame"), q.Get("view"), slice, r.Body); err != nil {
 		if err == ErrFrameNotFound {
 			http.Error(w, ErrFrameNotFound.Error(), http.StatusNotFound)
 		} else {
@@ -1230,19 +1221,11 @@ func (h *Handler) handlePostFragmentData(w http.ResponseWriter, r *http.Request)
 
 // handleGetFragmentBlockData handles GET /fragment/block/data requests.
 func (h *Handler) handleGetFragmentBlockData(w http.ResponseWriter, r *http.Request) {
-	// Read request object.
-	var req internal.BlockDataRequest
-	if body, err := ioutil.ReadAll(r.Body); err != nil {
-		http.Error(w, "ready body error", http.StatusBadRequest)
-		return
-	} else if err := proto.Unmarshal(body, &req); err != nil {
-		http.Error(w, "unmarshal body error", http.StatusBadRequest)
-		return
-	}
-
-	resp, err := h.API.FragmentBlockData(r.Context(), req)
+	buf, err := h.API.FragmentBlockData(r.Context(), r.Body)
 	if err != nil {
-		if err == ErrFragmentNotFound {
+		if _, ok := err.(BadRequestError); ok {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+		} else if err == ErrFragmentNotFound {
 			http.Error(w, err.Error(), http.StatusNotFound)
 		} else {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
@@ -1250,13 +1233,6 @@ func (h *Handler) handleGetFragmentBlockData(w http.ResponseWriter, r *http.Requ
 		return
 	}
 
-	// Encode response.
-	buf, err := proto.Marshal(&resp)
-	if err != nil {
-		h.Logger.Printf("merge block response encoding error: %s", err)
-		return
-	}
-
 	// Write response.
 	w.Header().Set("Content-Type", "application/protobuf")
 	w.Header().Set("Content-Length", strconv.Itoa(len(buf)))
@@ -1329,7 +1305,7 @@ func (h *Handler) handlePostFrameRestore(w http.ResponseWriter, r *http.Request)
 
 // handleGetHosts handles /hosts requests.
 func (h *Handler) handleGetHosts(w http.ResponseWriter, r *http.Request) {
-	hosts := h.API.ClusterHosts(r.Context())
+	hosts := h.API.Hosts(r.Context())
 	if err := json.NewEncoder(w).Encode(hosts); err != nil {
 		h.Logger.Printf("write version response error: %s", err)
 	}
@@ -1337,36 +1313,16 @@ func (h *Handler) handleGetHosts(w http.ResponseWriter, r *http.Request) {
 
 // handleGetVersion handles /version requests.
 func (h *Handler) handleGetVersion(w http.ResponseWriter, r *http.Request) {
-	version := Version
-	if strings.HasPrefix(version, "v") {
-		// make the version string semver-compatible
-		version = version[1:]
-	}
-	if err := json.NewEncoder(w).Encode(struct {
+	err := json.NewEncoder(w).Encode(struct {
 		Version string `json:"version"`
 	}{
-		Version: version,
-	}); err != nil {
+		Version: h.API.Version(),
+	})
+	if err != nil {
 		h.Logger.Printf("write version response error: %s", err)
 	}
 }
 
-// handleExpvar handles /debug/vars requests.
-func (h *Handler) handleExpvar(w http.ResponseWriter, r *http.Request) {
-	// Copied from $GOROOT/src/expvar/expvar.go
-	w.Header().Set("Content-Type", "application/json; charset=utf-8")
-	fmt.Fprintf(w, "{\n")
-	first := true
-	expvar.Do(func(kv expvar.KeyValue) {
-		if !first {
-			fmt.Fprintf(w, ",\n")
-		}
-		first = false
-		fmt.Fprintf(w, "%q: %s", kv.Key, kv.Value)
-	})
-	fmt.Fprintf(w, "\n}\n")
-}
-
 // QueryResult types.
 const (
 	QueryResultTypeNil uint32 = iota
@@ -1771,23 +1727,10 @@ func (h *Handler) handlePostClusterMessage(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	// Read entire body.
-	body, err := ioutil.ReadAll(r.Body)
+	err := h.API.PostClusterMessage(r.Context(), r.Body)
 	if err != nil {
+		// TODO this was the previous behavior, but perhaps not everything is a bad request
 		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
-	}
-
-	// Marshal into request object.
-	pb, err := UnmarshalMessage(body)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
-	}
-
-	if err := h.API.PostClusterMessage(r.Context(), pb); err != nil {
-		http.Error(w, err.Error(), http.StatusBadRequest)
-		return
 	}
 
 	if err := json.NewEncoder(w).Encode(defaultClusterMessageResponse{}); err != nil {
@@ -1809,7 +1752,7 @@ type queryValidationSpec struct {
 	args     map[string]struct{}
 }
 
-func QueryValidationSpecRequired(requiredArgs ...string) *queryValidationSpec {
+func queryValidationSpecRequired(requiredArgs ...string) *queryValidationSpec {
 	args := map[string]struct{}{}
 	for _, arg := range requiredArgs {
 		args[arg] = struct{}{}
diff --git a/handler_test.go b/handler_test.go
index b605a3650..c7d2a80b7 100644
--- a/handler_test.go
+++ b/handler_test.go
@@ -141,6 +141,7 @@ func TestHandler_Status(t *testing.T) {
 	h := test.NewHandler()
 	h.API.Holder = hldr.Holder
 	h.API.Cluster = test.NewCluster(1)
+	h.API.Cluster.SetState(pilosa.ClusterStateNormal)
 	h.API.StatusHandler = s
 	s.Handler = h
 
@@ -148,7 +149,7 @@ func TestHandler_Status(t *testing.T) {
 	h.ServeHTTP(w, test.MustNewHTTPRequest("GET", "/status", nil))
 	if w.Code != http.StatusOK {
 		t.Fatalf("unexpected status code: %d", w.Code)
-	} else if body := w.Body.String(); body != `{"state":"NORMAL","nodes":[{"id":"test-node","uri":{"scheme":"http","host":"localhost","port":10101},"isCoordinator":false}]}`+"\n" {
+	} else if body := w.Body.String(); body != `{"state":"NORMAL","nodes":[{"id":"node0","uri":{"scheme":"http","host":"host0"},"isCoordinator":false}]}`+"\n" {
 		t.Fatalf("unexpected body: %s", body)
 	}
 }
diff --git a/holder.go b/holder.go
index 22c53c7a4..570433ce4 100644
--- a/holder.go
+++ b/holder.go
@@ -614,7 +614,7 @@ func (s *HolderSyncer) SyncHolder() error {
 
 				for slice := uint64(0); slice <= s.Holder.Index(di.Name).MaxSlice(); slice++ {
 					// Ignore slices that this host doesn't own.
-					if !s.Cluster.OwnsFragment(s.Node.ID, di.Name, slice) {
+					if !s.Cluster.OwnsSlice(s.Node.ID, di.Name, slice) {
 						continue
 					}
 
diff --git a/pilosa.go b/pilosa.go
index 4b28daccb..ffb836ae8 100644
--- a/pilosa.go
+++ b/pilosa.go
@@ -82,6 +82,13 @@ var (
 	ErrResizeNotRunning   = errors.New("no resize job currently running")
 )
 
+// BadRequestError wraps an error value to signify that a request could not be
+// read, decoded, or parsed such that in an HTTP scenario, http.StatusBadRequest
+// would be returned.
+type BadRequestError struct {
+	error
+}
+
 // Regular expression to validate index and frame names.
 var nameRegexp = regexp.MustCompile(`^[a-z][a-z0-9_-]{0,63}$`)
 
diff --git a/test/cluster.go b/test/cluster.go
index 8362ca964..308a7e69c 100644
--- a/test/cluster.go
+++ b/test/cluster.go
@@ -129,7 +129,7 @@ func (t *TestCluster) SetBit(index, frame, view string, rowID, colID uint64, x *
 	// Determine which node should receive the SetBit.
 	c0 := t.Clusters[0] // use the first node's cluster to determine slice location.
 	slice := colID / pilosa.SliceWidth
-	nodes := c0.FragmentNodes(index, slice)
+	nodes := c0.SliceNodes(index, slice)
 
 	for _, node := range nodes {
 		c := t.clusterByID(node.ID)
@@ -153,7 +153,7 @@ func (t *TestCluster) SetFieldValue(index, frame string, columnID uint64, name s
 	// Determine which node should receive the SetFieldValue.
 	c0 := t.Clusters[0] // use the first node's cluster to determine slice location.
 	slice := columnID / pilosa.SliceWidth
-	nodes := c0.FragmentNodes(index, slice)
+	nodes := c0.SliceNodes(index, slice)
 
 	for _, node := range nodes {
 		c := t.clusterByID(node.ID)