diff --git a/api/krusty/kustomizer.go b/api/krusty/kustomizer.go
index 316699ee6..b6bcdf3ca 100644
--- a/api/krusty/kustomizer.go
+++ b/api/krusty/kustomizer.go
@@ -10,7 +10,6 @@ import (
 	"sigs.k8s.io/kustomize/api/k8sdeps/validator"
 	fLdr "sigs.k8s.io/kustomize/api/loader"
 	"sigs.k8s.io/kustomize/api/plugins/builtins"
-	"sigs.k8s.io/kustomize/api/plugins/config"
 	pLdr "sigs.k8s.io/kustomize/api/plugins/loader"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
@@ -43,20 +42,20 @@ func MakeKustomizer(fSys filesys.FileSystem, o *Options) *Kustomizer {
 // It uses its internal filesystem reference to read the file at
 // the given path argument, interpret it as a kustomization.yaml
 // file, perform the kustomization it represents, and return the
-// resulting YAML as bytes.
+// resulting resources.
 //
 // Any files referenced by the kustomization must be present in the
 // internal filesystem.  One may call Run any number of times,
 // on any number of internal paths (e.g. the filesystem may contain
 // multiple overlays, and Run can be called on each of them).
-func (b *Kustomizer) Run(path string) ([]byte, error) {
+func (b *Kustomizer) Run(path string) (resmap.ResMap, error) {
 	pf := transformer.NewFactoryImpl()
 	rf := resmap.NewFactory(
 		resource.NewFactory(
 			kunstruct.NewKunstructuredFactoryImpl()),
 		pf)
 	lr := fLdr.RestrictionNone
-	if b.options.RestrictToRootOnly {
+	if b.options.LoadRestrictions == rootOnly {
 		lr = fLdr.RestrictionRootOnly
 	}
 	ldr, err := fLdr.NewLoader(lr, path, b.fSys)
@@ -69,17 +68,22 @@ func (b *Kustomizer) Run(path string) ([]byte, error) {
 		validator.NewKustValidator(),
 		rf,
 		pf,
-		pLdr.NewLoader(config.DefaultPluginConfig(), rf),
+		pLdr.NewLoader(b.options.PluginConfig, rf),
 	)
 	if err != nil {
 		return nil, err
 	}
-	m, err := kt.MakeCustomizedResMap()
+	var m resmap.ResMap
+	if b.options.DoPrune {
+		m, err = kt.MakePruneConfigMap()
+	} else {
+		m, err = kt.MakeCustomizedResMap()
+	}
 	if err != nil {
 		return nil, err
 	}
 	if b.options.DoLegacyResourceSort {
 		builtins.NewLegacyOrderTransformerPlugin().Transform(m)
 	}
-	return m.AsYaml()
+	return m, nil
 }
diff --git a/api/krusty/loadrestrictions.go b/api/krusty/loadrestrictions.go
new file mode 100644
index 000000000..8312a9407
--- /dev/null
+++ b/api/krusty/loadrestrictions.go
@@ -0,0 +1,68 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package krusty
+
+import (
+	"fmt"
+	"github.com/spf13/pflag"
+)
+
+//go:generate stringer -type=loadRestrictions
+type loadRestrictions int
+
+const (
+	unknown loadRestrictions = iota
+
+	// With this restriction, the files referenced by a
+	// kustomization file must be in or under the directory
+	// holding the kustomization file itself.
+	rootOnly
+
+	// The kustomization file may specify absolute or
+	// relative paths to patch or resources files outside
+	// its own tree.
+	none
+)
+
+const (
+	flagName = "load_restrictor"
+)
+
+var (
+	flagValue = rootOnly.String()
+	flagHelp  = "if set to '" + none.String() +
+		"', local kustomizations may load files from outside their root. " +
+		"This does, however, break the relocatability of the kustomization."
+)
+
+func AddFlagLoadRestrictor(set *pflag.FlagSet) {
+	set.StringVar(
+		&flagValue, flagName,
+		rootOnly.String(), flagHelp)
+}
+
+func ValidateFlagLoadRestrictor() error {
+	switch flagValue {
+	case rootOnly.String():
+		return nil
+	case none.String():
+		return nil
+	default:
+		return fmt.Errorf(
+			"illegal flag value --%s %s; legal values: %v",
+			flagName, flagValue,
+			[]string{rootOnly.String(), none.String()})
+	}
+}
+
+func GetFlagLoadRestrictorValue() loadRestrictions {
+	switch flagValue {
+	case rootOnly.String():
+		return rootOnly
+	case none.String():
+		return none
+	default:
+		return unknown
+	}
+}
diff --git a/api/loader/loadrestrictions_string.go b/api/krusty/loadrestrictions_string.go
similarity index 54%
rename from api/loader/loadrestrictions_string.go
rename to api/krusty/loadrestrictions_string.go
index 42ddca791..1f1d099ae 100644
--- a/api/loader/loadrestrictions_string.go
+++ b/api/krusty/loadrestrictions_string.go
@@ -1,22 +1,6 @@
-/*
-Copyright 2019 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
 // Code generated by "stringer -type=loadRestrictions"; DO NOT EDIT.
 
-package loader
+package krusty
 
 import "strconv"
 
diff --git a/api/krusty/options.go b/api/krusty/options.go
index 978b9f1cd..f7377ffaa 100644
--- a/api/krusty/options.go
+++ b/api/krusty/options.go
@@ -3,27 +3,38 @@
 
 package krusty
 
-// Options holds high-level configuration options, e.g.
-// are plugins enabled, should the loader be restricted to
-// the kustomization root, etc.
+import (
+	"sigs.k8s.io/kustomize/api/plugins/config"
+	"sigs.k8s.io/kustomize/api/types"
+)
+
+// Options holds high-level kustomize configuration options,
+// e.g. are plugins enabled, should the loader be restricted
+// to the kustomization root, etc.
 type Options struct {
 	// When true, sort the resources before emitting them,
 	// per a particular sort order.  When false, don't do the
 	// sort, and instead respect the depth-first resource input
 	// order as specified by the kustomization file(s).
 	DoLegacyResourceSort bool
-	// When true, the files referenced by a kustomization file
-	// must be in or under the directory holding the kustomization
-	// file itself.  When false, the kustomization file may specify
-	// absolute or relative paths to patch or resources files outside
-	// its own tree.
-	RestrictToRootOnly bool
+
+	// Restrictions on what can be loaded from the file system.
+	// See type definition.
+	LoadRestrictions loadRestrictions
+
+	// Create an inventory object for pruning.
+	DoPrune bool
+
+	// Options related to kustomize plugins.
+	PluginConfig *types.PluginConfig
 }
 
 // MakeDefaultOptions returns a default instance of Options.
 func MakeDefaultOptions() *Options {
 	return &Options{
 		DoLegacyResourceSort: true,
-		RestrictToRootOnly:   true,
+		LoadRestrictions:     rootOnly,
+		DoPrune:              false,
+		PluginConfig:         config.DefaultPluginConfig(),
 	}
 }
diff --git a/api/loader/loadrestrictions.go b/api/loader/loadrestrictions.go
index c1c935cf1..d1f5da8f7 100644
--- a/api/loader/loadrestrictions.go
+++ b/api/loader/loadrestrictions.go
@@ -6,50 +6,9 @@ package loader
 import (
 	"fmt"
 
-	"github.com/spf13/pflag"
 	"sigs.k8s.io/kustomize/api/filesys"
 )
 
-//go:generate stringer -type=loadRestrictions
-type loadRestrictions int
-
-const (
-	unknown loadRestrictions = iota
-	rootOnly
-	none
-)
-
-const (
-	flagName = "load_restrictor"
-)
-
-var (
-	flagValue = rootOnly.String()
-	flagHelp  = "if set to '" + none.String() +
-		"', local kustomizations may load files from outside their root. " +
-		"This does, however, break the relocatability of the kustomization."
-)
-
-func AddFlagLoadRestrictor(set *pflag.FlagSet) {
-	set.StringVar(
-		&flagValue, flagName,
-		rootOnly.String(), flagHelp)
-}
-
-func ValidateFlagLoadRestrictor() (LoadRestrictorFunc, error) {
-	switch flagValue {
-	case rootOnly.String():
-		return RestrictionRootOnly, nil
-	case none.String():
-		return RestrictionNone, nil
-	default:
-		return nil, fmt.Errorf(
-			"illegal flag value --%s %s; legal values: %v",
-			flagName, flagValue,
-			[]string{rootOnly.String(), none.String()})
-	}
-}
-
 type LoadRestrictorFunc func(
 	filesys.FileSystem, filesys.ConfirmedDir, string) (string, error)
 
diff --git a/api/loader/loadrestrictions_test.go b/api/loader/loadrestrictions_test.go
index 53fa41fd3..e1ef8d119 100644
--- a/api/loader/loadrestrictions_test.go
+++ b/api/loader/loadrestrictions_test.go
@@ -1,18 +1,5 @@
-/*
-Copyright 2018 The Kubernetes Authors.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
 
 package loader
 
diff --git a/kustomize/internal/commands/build/build.go b/kustomize/internal/commands/build/build.go
index 8c276ca97..d51708a25 100644
--- a/kustomize/internal/commands/build/build.go
+++ b/kustomize/internal/commands/build/build.go
@@ -11,15 +11,11 @@ import (
 	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/api/filesys"
-	"sigs.k8s.io/kustomize/api/ifc"
-	fLdr "sigs.k8s.io/kustomize/api/loader"
+	"sigs.k8s.io/kustomize/api/krusty"
 	"sigs.k8s.io/kustomize/api/pgmconfig"
-	"sigs.k8s.io/kustomize/api/plugins/builtins"
 	"sigs.k8s.io/kustomize/api/plugins/config"
-	pLdr "sigs.k8s.io/kustomize/api/plugins/loader"
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
-	"sigs.k8s.io/kustomize/api/target"
 	"sigs.k8s.io/yaml"
 )
 
@@ -27,8 +23,8 @@ import (
 type Options struct {
 	kustomizationPath string
 	outputPath        string
-	loadRestrictor    fLdr.LoadRestrictorFunc
 	outOrder          reorderOutput
+	pluginsEnabled    bool
 }
 
 // NewOptions creates a Options object
@@ -36,7 +32,6 @@ func NewOptions(p, o string) *Options {
 	return &Options{
 		kustomizationPath: p,
 		outputPath:        o,
-		loadRestrictor:    fLdr.RestrictionRootOnly,
 	}
 }
 
@@ -58,15 +53,8 @@ https://github.com/hashicorp/go-getter#url-format
 `
 
 // NewCmdBuild creates a new build command.
-func NewCmdBuild(
-	out io.Writer, fSys filesys.FileSystem,
-	v ifc.Validator, rf *resmap.Factory,
-	ptf resmap.PatchFactory) *cobra.Command {
+func NewCmdBuild(out io.Writer) *cobra.Command {
 	var o Options
-
-	pluginConfig := config.DefaultPluginConfig()
-	pl := pLdr.NewLoader(pluginConfig, rf)
-
 	cmd := &cobra.Command{
 		Use: "build {path}",
 		Short: "Print configuration per contents of " +
@@ -78,7 +66,7 @@ func NewCmdBuild(
 			if err != nil {
 				return err
 			}
-			return o.RunBuild(out, v, fSys, rf, ptf, pl)
+			return o.RunBuild(out)
 		},
 	}
 
@@ -86,14 +74,16 @@ func NewCmdBuild(
 		&o.outputPath,
 		"output", "o", "",
 		"If specified, write the build output to this path.")
-	fLdr.AddFlagLoadRestrictor(cmd.Flags())
+	krusty.AddFlagLoadRestrictor(cmd.Flags())
 	config.AddFlagEnablePlugins(
-		cmd.Flags(), &pluginConfig.Enabled)
+		cmd.Flags(), &o.pluginsEnabled)
 	addFlagReorderOutput(cmd.Flags())
-	cmd.AddCommand(NewCmdBuildPrune(out, v, fSys, rf, ptf, pl))
+	cmd.AddCommand(NewCmdBuildPrune(out))
 	return cmd
 }
 
+const CWD = "."
+
 // Validate validates build command.
 func (o *Options) Validate(args []string) (err error) {
 	if len(args) > 1 {
@@ -102,11 +92,11 @@ func (o *Options) Validate(args []string) (err error) {
 				pgmconfig.DefaultKustomizationFileName())
 	}
 	if len(args) == 0 {
-		o.kustomizationPath = fLdr.CWD
+		o.kustomizationPath = CWD
 	} else {
 		o.kustomizationPath = args[0]
 	}
-	o.loadRestrictor, err = fLdr.ValidateFlagLoadRestrictor()
+	err = krusty.ValidateFlagLoadRestrictor()
 	if err != nil {
 		return err
 	}
@@ -114,43 +104,30 @@ func (o *Options) Validate(args []string) (err error) {
 	return
 }
 
-// RunBuild runs build command.
-func (o *Options) RunBuild(
-	out io.Writer, v ifc.Validator, fSys filesys.FileSystem,
-	rf *resmap.Factory, ptf resmap.PatchFactory,
-	pl *pLdr.Loader) error {
-	ldr, err := fLdr.NewLoader(
-		o.loadRestrictor, o.kustomizationPath, fSys)
-	if err != nil {
-		return err
-	}
-	defer ldr.Cleanup()
-	kt, err := target.NewKustTarget(ldr, v, rf, ptf, pl)
-	if err != nil {
-		return err
-	}
-	m, err := kt.MakeCustomizedResMap()
+func (o *Options) makeOptions() *krusty.Options {
+	opts := krusty.MakeDefaultOptions()
+	opts.LoadRestrictions = krusty.GetFlagLoadRestrictorValue()
+	opts.DoLegacyResourceSort = o.outOrder == legacy
+	opts.PluginConfig.Enabled = o.pluginsEnabled
+	return opts
+}
+
+func (o *Options) RunBuild(out io.Writer) error {
+	fSys := filesys.MakeFsOnDisk()
+	k := krusty.MakeKustomizer(fSys, o.makeOptions())
+	m, err := k.Run(o.kustomizationPath)
 	if err != nil {
 		return err
 	}
 	return o.emitResources(out, fSys, m)
 }
 
-func (o *Options) RunBuildPrune(
-	out io.Writer, v ifc.Validator, fSys filesys.FileSystem,
-	rf *resmap.Factory, ptf resmap.PatchFactory,
-	pl *pLdr.Loader) error {
-	ldr, err := fLdr.NewLoader(
-		o.loadRestrictor, o.kustomizationPath, fSys)
-	if err != nil {
-		return err
-	}
-	defer ldr.Cleanup()
-	kt, err := target.NewKustTarget(ldr, v, rf, ptf, pl)
-	if err != nil {
-		return err
-	}
-	m, err := kt.MakePruneConfigMap()
+func (o *Options) RunBuildPrune(out io.Writer) error {
+	fSys := filesys.MakeFsOnDisk()
+	opts := o.makeOptions()
+	opts.DoPrune = true
+	k := krusty.MakeKustomizer(fSys, opts)
+	m, err := k.Run(o.kustomizationPath)
 	if err != nil {
 		return err
 	}
@@ -162,13 +139,6 @@ func (o *Options) emitResources(
 	if o.outputPath != "" && fSys.IsDir(o.outputPath) {
 		return writeIndividualFiles(fSys, o.outputPath, m)
 	}
-	if o.outOrder == legacy {
-		// Done this way just to show how overall sorting
-		// can be performed by a plugin.  This particular
-		// plugin doesn't require configuration; just make
-		// it and call transform.
-		builtins.NewLegacyOrderTransformerPlugin().Transform(m)
-	}
 	res, err := m.AsYaml()
 	if err != nil {
 		return err
@@ -180,12 +150,8 @@ func (o *Options) emitResources(
 	return err
 }
 
-func NewCmdBuildPrune(
-	out io.Writer, v ifc.Validator, fSys filesys.FileSystem,
-	rf *resmap.Factory, ptf resmap.PatchFactory,
-	pl *pLdr.Loader) *cobra.Command {
+func NewCmdBuildPrune(out io.Writer) *cobra.Command {
 	var o Options
-
 	cmd := &cobra.Command{
 		Use:          "alpha-inventory [path]",
 		Short:        "Print the inventory object which contains a list of all other objects",
@@ -196,7 +162,7 @@ func NewCmdBuildPrune(
 			if err != nil {
 				return err
 			}
-			return o.RunBuildPrune(out, v, fSys, rf, ptf, pl)
+			return o.RunBuildPrune(out)
 		},
 	}
 	return cmd
diff --git a/kustomize/internal/commands/commands.go b/kustomize/internal/commands/commands.go
index 796ef2484..6f84b5c45 100644
--- a/kustomize/internal/commands/commands.go
+++ b/kustomize/internal/commands/commands.go
@@ -11,11 +11,8 @@ import (
 	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/api/filesys"
 	"sigs.k8s.io/kustomize/api/k8sdeps/kunstruct"
-	"sigs.k8s.io/kustomize/api/k8sdeps/transformer"
 	"sigs.k8s.io/kustomize/api/k8sdeps/validator"
 	"sigs.k8s.io/kustomize/api/pgmconfig"
-	"sigs.k8s.io/kustomize/api/resmap"
-	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/kustomize/v3/internal/commands/build"
 	"sigs.k8s.io/kustomize/kustomize/v3/internal/commands/config"
 	"sigs.k8s.io/kustomize/kustomize/v3/internal/commands/create"
@@ -36,15 +33,10 @@ Manages declarative configuration of Kubernetes.
 See https://sigs.k8s.io/kustomize
 `,
 	}
-
 	uf := kunstruct.NewKunstructuredFactoryImpl()
-	pf := transformer.NewFactoryImpl()
-	rf := resmap.NewFactory(resource.NewFactory(uf), pf)
 	v := validator.NewKustValidator()
 	c.AddCommand(
-		build.NewCmdBuild(
-			stdOut, fSys, v,
-			rf, pf),
+		build.NewCmdBuild(stdOut),
 		edit.NewCmdEdit(fSys, v, uf),
 		create.NewCmdCreate(fSys, uf),
 		config.NewCmdConfig(fSys),