diff --git a/internal/transport/file.go b/internal/transport/file.go
index c16b159..2949b39 100644
--- a/internal/transport/file.go
+++ b/internal/transport/file.go
@@ -13,6 +13,7 @@ _	"errors"
 	"fmt"
 	"compress/gzip"
 	"log/slog"
+	"decl/internal/ext"
 )
 
 type File struct {
@@ -98,6 +99,7 @@ func NewFileWriter(u *url.URL) (f *FileWriter, err error) {
 	}
 	f.extension()
 	f.DetectGzip()
+	slog.Info("transport.NewFileWriter()", "file", f.File)
 	exists := FileExists(u)
 	slog.Info("transport.NewFileWriter()", "file", f, "error", err, "exists", exists)
 
@@ -110,7 +112,7 @@ func NewFileWriter(u *url.URL) (f *FileWriter, err error) {
 		}
 	}
 	if f.Gzip() {
-		f.gzipWriter = gzip.NewWriter(f.writeHandle)
+		f.gzipWriter = ext.WriteAddCloser(gzip.NewWriter(f.writeHandle), func() error { return f.writeHandle.Close() })
 	}
 	slog.Info("transport.NewFileWriter()", "file", f, "error", err)
 	return
@@ -139,7 +141,7 @@ func NewFile(u *url.URL) (f *File, err error) {
 	}
 
 	if f.Gzip() {
-		f.gzipWriter = gzip.NewWriter(f.writeHandle)
+		f.gzipWriter = ext.WriteAddCloser(gzip.NewWriter(f.writeHandle), func() error { return f.writeHandle.Close() })
 		if exists {
 			if f.gzipReader, err = gzip.NewReader(f.readHandle); err != nil {
 				return
@@ -164,7 +166,7 @@ func (f *File) extension() {
 }
 
 func (f *File) DetectGzip() {
-	f.gzip = (f.uri.Query().Get("gzip") == "true" || f.fileext == "gz") 
+	f.gzip = (f.uri.Query().Get("gzip") == "true" || f.fileext == "gz" || f.exttype == "tgz" || f.exttype == "gz" || f.fileext == "tgz") 
 }
 
 func (f *File) URI() *url.URL {
diff --git a/internal/transport/file_test.go b/internal/transport/file_test.go
index cfc8195..915ffb0 100644
--- a/internal/transport/file_test.go
+++ b/internal/transport/file_test.go
@@ -7,8 +7,11 @@ import (
 	"testing"
 	"fmt"
 	"os"
+	"io"
 	"net/url"
 	"path/filepath"
+	"compress/gzip"
+	"strings"
 )
 
 var TransportFileTestFile = fmt.Sprintf("%s/foo", TempDir)
@@ -37,3 +40,35 @@ func TestNewTransportFileReaderExtension(t *testing.T) {
 	f.extension()
 	assert.Equal(t, f.exttype, "yaml")
 }
+
+// Use transport to write a compressed file then verify it.
+func TestTransportFileGzipWriter(t *testing.T) {
+	var content strings.Builder
+	var testValue string = "write a compressed plaintext file"
+
+	path := TempDir.FilePath("foo.tgz")
+	u, e := url.Parse(fmt.Sprintf("file://%s", path))
+	assert.Nil(t, e)
+	
+	fw, err := NewFileWriter(u)
+	assert.Nil(t, err)
+	assert.Equal(t, "tgz", fw.File.exttype)
+
+	assert.True(t, fw.Gzip())
+	
+	writer := fw.Writer()
+	writer.Write([]byte(testValue))
+	assert.Nil(t, writer.Close())
+
+	assert.True(t, TempDir.FileExists("foo.tgz"))
+
+	r, openErr := TempDir.Open("foo.tgz")
+	assert.Nil(t, openErr)
+	gzipReader, gzipErr := gzip.NewReader(r)
+	assert.Nil(t, gzipErr)
+	_, readErr := io.Copy(&content, gzipReader)
+	assert.Nil(t, readErr)
+	assert.Equal(t, content.String(), testValue)
+}
+
+
diff --git a/internal/transport/transport.go b/internal/transport/transport.go
index bcfa964..1a75de3 100644
--- a/internal/transport/transport.go
+++ b/internal/transport/transport.go
@@ -19,6 +19,7 @@ type Handler interface {
 	URI() *url.URL
 	ContentType() string
 	SetGzip(bool)
+	DetectGzip()
 	Gzip() bool
 	Signature() string
 	Stat() (fs.FileInfo, error)
@@ -138,6 +139,8 @@ func (r *Reader) SetGzip(value bool) {
 	r.handle.SetGzip(value)
 }
 
+func (r *Reader) DetectGzip() { r.handle.DetectGzip() }
+
 func (r *Reader) Gzip() bool {
 	return r.handle.Gzip()
 }
@@ -196,6 +199,8 @@ func (w *Writer) SetGzip(value bool) {
 	w.handle.SetGzip(value)
 }
 
+func (w *Writer) DetectGzip() { w.handle.DetectGzip() }
+
 func (w *Writer) Gzip() bool {
 	return w.handle.Gzip()
 }
diff --git a/internal/transport/transport_test.go b/internal/transport/transport_test.go
index d24a477..a7aa763 100644
--- a/internal/transport/transport_test.go
+++ b/internal/transport/transport_test.go
@@ -9,9 +9,10 @@ import (
 	"fmt"
 	"os"
 	"log"
+	"decl/internal/tempdir"
 )
 
-var TempDir string
+var TempDir tempdir.Path = "testtransportfile"
 
 var testFileResourceDoc string = `
 resources:
@@ -23,19 +24,19 @@ resources:
 
 func TestMain(m *testing.M) {
 	var err error
-	TempDir, err = os.MkdirTemp("", "testtransportfile")
+	err = TempDir.Create()
 	if err != nil || TempDir == "" {
 		log.Fatal(err)
 	}
 
 	rc := m.Run()
 
-	os.RemoveAll(TempDir)
+	TempDir.Remove()
 	os.Exit(rc)
 }
 
 func TestNewTransportReader(t *testing.T) {
-	path := fmt.Sprintf("%s/foo", TempDir)
+	path := TempDir.FilePath("foo")
 	u, e := url.Parse(fmt.Sprintf("file://%s", path))
 	assert.Nil(t, e)
 
@@ -48,7 +49,7 @@ func TestNewTransportReader(t *testing.T) {
 }
 
 func TestTransportReaderContentType(t *testing.T) {
-	path := fmt.Sprintf("%s/foo.jx.yaml", TempDir)
+	path := TempDir.FilePath("foo.jx.yaml")
 	u, e := url.Parse(fmt.Sprintf("file://%s", path))
 	assert.Nil(t, e)
 
@@ -66,7 +67,7 @@ func TestTransportReaderContentType(t *testing.T) {
 }
 
 func TestTransportReaderDir(t *testing.T) {
-	u, e := url.Parse(fmt.Sprintf("file://%s", TempDir))
+	u, e := url.Parse(fmt.Sprintf("file://%s", string(TempDir)))
 	assert.Nil(t, e)
 
 	reader, err := NewReader(u)
@@ -76,7 +77,7 @@ func TestTransportReaderDir(t *testing.T) {
 }
 
 func TestTransportWriter(t *testing.T) {
-	path := fmt.Sprintf("%s/writefoo", TempDir)
+	path := TempDir.FilePath("writefoo")
 	u, e := url.Parse(fmt.Sprintf("file://%s", path))
 	assert.Nil(t, e)