diff --git a/generate-car.go b/generate-car.go
index e189478..14fa7b8 100644
--- a/generate-car.go
+++ b/generate-car.go
@@ -6,6 +6,11 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
+	"log"
+	"os"
+	"path"
+
 	commcid "github.com/filecoin-project/go-fil-commcid"
 	"github.com/filecoin-project/go-fil-commp-hashhash"
 	"github.com/google/uuid"
@@ -13,10 +18,6 @@ import (
 	cbor "github.com/ipfs/go-ipld-cbor"
 	"github.com/tech-greedy/go-generate-car/util"
 	"github.com/urfave/cli/v2"
-	"io"
-	"log"
-	"os"
-	"path"
 )
 
 type CommpResult struct {
@@ -51,6 +52,10 @@ func main() {
 		Name:  "generate-car",
 		Usage: "generate car archive from list of files and compute commp in the mean time",
 		Flags: []cli.Flag{
+			&cli.BoolFlag{
+				Name:  "single",
+				Usage: "When enabled, it indicates that the input is a single file to be included in full, instead of a spec JSON",
+			},
 			&cli.StringFlag{
 				Name:    "input",
 				Aliases: []string{"i"},
@@ -88,26 +93,41 @@ func main() {
 			outDir := c.String("out-dir")
 			parent := c.String("parent")
 			tmpDir := c.String("tmp-dir")
-			var inputBytes []byte
-			if inputFile == "-" {
-				reader := bufio.NewReader(os.Stdin)
-				buf := new(bytes.Buffer)
-				_, err := buf.ReadFrom(reader)
+			single := c.Bool("single")
+
+			var input Input
+			if single {
+				stat, err := os.Stat(inputFile)
 				if err != nil {
 					return err
 				}
-				inputBytes = buf.Bytes()
+				input = append(input, util.Finfo{
+					Path:  inputFile,
+					Size:  stat.Size(),
+					Start: 0,
+					End:   stat.Size(),
+				})
 			} else {
-				bytes, err := os.ReadFile(inputFile)
+				var inputBytes []byte
+				if inputFile == "-" {
+					reader := bufio.NewReader(os.Stdin)
+					buf := new(bytes.Buffer)
+					_, err := buf.ReadFrom(reader)
+					if err != nil {
+						return err
+					}
+					inputBytes = buf.Bytes()
+				} else {
+					bytes, err := os.ReadFile(inputFile)
+					if err != nil {
+						return err
+					}
+					inputBytes = bytes
+				}
+				err := json.Unmarshal(inputBytes, &input)
 				if err != nil {
 					return err
 				}
-				inputBytes = bytes
-			}
-			var input Input
-			err := json.Unmarshal(inputBytes, &input)
-			if err != nil {
-				return err
 			}
 
 			outFilename := uuid.New().String() + ".car"