diff --git a/neo/api.go b/neo/api.go
index ab687947..5e1b837c 100644
--- a/neo/api.go
+++ b/neo/api.go
@@ -2,7 +2,9 @@ package neo
 
 import (
 	"fmt"
+	"io"
 	"net/url"
+	"path/filepath"
 	"strings"
 
 	"github.com/gin-gonic/gin"
@@ -28,6 +30,7 @@ func (neo *DSL) API(router *gin.Engine, path string) error {
 	router.OPTIONS(path+"/chats", neo.optionsHandler)
 	router.OPTIONS(path+"/history", neo.optionsHandler)
 	router.OPTIONS(path+"/upload", neo.optionsHandler)
+	router.OPTIONS(path+"/download", neo.optionsHandler)
 
 	// Register endpoints with middlewares
 	router.GET(path, append(middlewares, neo.handleChat)...)
@@ -36,6 +39,7 @@ func (neo *DSL) API(router *gin.Engine, path string) error {
 	router.GET(path+"/chats", append(middlewares, neo.handleChatList)...)
 	router.GET(path+"/history", append(middlewares, neo.handleChatHistory)...)
 	router.POST(path+"/upload", append(middlewares, neo.handleUpload)...)
+	router.GET(path+"/download", append(middlewares, neo.handleDownload)...)
 	return nil
 }
 
@@ -135,6 +139,49 @@ func (neo *DSL) handleChatHistory(c *gin.Context) {
 	c.Done()
 }
 
+// handleDownload handles the download request
+func (neo *DSL) handleDownload(c *gin.Context) {
+	sid := c.GetString("__sid")
+	if sid == "" {
+		c.JSON(400, gin.H{"message": "sid is required", "code": 400})
+		c.Done()
+		return
+	}
+
+	fileID := c.Query("file_id")
+	if fileID == "" {
+		c.JSON(400, gin.H{"message": "file_id is required", "code": 400})
+		c.Done()
+		return
+	}
+
+	// Set the context
+	ctx, cancel := NewContextWithCancel(sid, c.Query("chat_id"), "")
+	defer cancel()
+
+	// Download the file
+	fileResponse, err := neo.Download(ctx, c)
+	if err != nil {
+		c.JSON(500, gin.H{"message": err.Error(), "code": 500})
+		c.Done()
+		return
+	}
+	defer fileResponse.Reader.Close()
+
+	// Set response headers
+	c.Header("Content-Type", fileResponse.ContentType)
+	if disposition := c.Query("disposition"); disposition == "attachment" {
+		c.Header("Content-Disposition", fmt.Sprintf("attachment; filename=%s", filepath.Base(fileID)+fileResponse.Extension))
+	}
+
+	// Copy the file content to response
+	_, err = io.Copy(c.Writer, fileResponse.Reader)
+	if err != nil {
+		c.JSON(500, gin.H{"message": err.Error(), "code": 500})
+		return
+	}
+}
+
 // getCorsHandlers returns CORS middleware handlers
 func (neo *DSL) getCorsHandlers() ([]gin.HandlerFunc, error) {
 	if len(neo.Allows) == 0 {
diff --git a/neo/assistant/base/file.go b/neo/assistant/base/file.go
index 8b7738f4..fd4f3029 100644
--- a/neo/assistant/base/file.go
+++ b/neo/assistant/base/file.go
@@ -49,7 +49,7 @@ func (ast *Base) Upload(ctx context.Context, file *multipart.FileHeader, reader
 	}
 
 	ext := filepath.Ext(file.Filename)
-	id, err := ast.id(file.Filename)
+	id, err := ast.id(file.Filename, ext)
 	if err != nil {
 		return nil, err
 	}
@@ -61,7 +61,7 @@ func (ast *Base) Upload(ctx context.Context, file *multipart.FileHeader, reader
 	}
 
 	return &assistant.File{
-		ID:          strings.ReplaceAll(id, "/", "_"),
+		ID:          filename,
 		Filename:    filename,
 		ContentType: contentType,
 		Bytes:       int(file.Size),
@@ -69,10 +69,10 @@ func (ast *Base) Upload(ctx context.Context, file *multipart.FileHeader, reader
 	}, nil
 }
 
-func (ast *Base) id(temp string) (string, error) {
+func (ast *Base) id(temp string, ext string) (string, error) {
 	date := time.Now().Format("20060102")
 	hash := fmt.Sprintf("%x", sha256.Sum256([]byte(temp)))[:8]
-	return fmt.Sprintf("/__assistants/%s/%s/%s", ast.ID, date, hash), nil
+	return fmt.Sprintf("/__assistants/%s/%s/%s%s", ast.ID, date, hash, ext), nil
 }
 
 func (ast *Base) allowed(contentType string) bool {
@@ -85,3 +85,50 @@ func (ast *Base) allowed(contentType string) bool {
 	}
 	return false
 }
+
+// Download downloads a file
+func (ast *Base) Download(ctx context.Context, fileID string) (*assistant.FileResponse, error) {
+
+	// Get the data filesystem
+	data, err := fs.Get("data")
+	if err != nil {
+		return nil, fmt.Errorf("get filesystem error: %s", err.Error())
+	}
+
+	// Check if file exists
+	exists, err := data.Exists(fileID)
+	if err != nil {
+		return nil, fmt.Errorf("check file error: %s", err.Error())
+	}
+	if !exists {
+		return nil, fmt.Errorf("file %s not found", fileID)
+	}
+
+	// Open the file
+	reader, err := data.ReadCloser(fileID)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get content type and extension
+	ext := filepath.Ext(fileID)
+
+	// Get content type from mime type
+	contentType := "application/octet-stream"
+	if v, err := data.MimeType(fileID); err == nil {
+		contentType = v
+	}
+
+	for mimeType, extension := range AllowedFileTypes {
+		if "."+extension == ext {
+			contentType = mimeType
+			break
+		}
+	}
+
+	return &assistant.FileResponse{
+		Reader:      reader,
+		ContentType: contentType,
+		Extension:   ext,
+	}, nil
+}
diff --git a/neo/assistant/openai/file.go b/neo/assistant/openai/file.go
index 7405d7eb..44892d49 100644
--- a/neo/assistant/openai/file.go
+++ b/neo/assistant/openai/file.go
@@ -49,19 +49,19 @@ func (ast *OpenAI) Upload(ctx context.Context, file *multipart.FileHeader, reade
 	}
 
 	ext := filepath.Ext(file.Filename)
-	id, err := ast.id(file.Filename)
+	id, err := ast.id(file.Filename, ext)
 	if err != nil {
 		return nil, err
 	}
 
-	filename := fmt.Sprintf("%s%s", id, ext)
+	filename := id
 	_, err = data.Write(filename, reader, 0644)
 	if err != nil {
 		return nil, err
 	}
 
 	return &assistant.File{
-		ID:          strings.ReplaceAll(id, "/", "_"),
+		ID:          filename,
 		Filename:    filename,
 		ContentType: contentType,
 		Bytes:       int(file.Size),
@@ -69,10 +69,10 @@ func (ast *OpenAI) Upload(ctx context.Context, file *multipart.FileHeader, reade
 	}, nil
 }
 
-func (ast *OpenAI) id(temp string) (string, error) {
+func (ast *OpenAI) id(temp string, ext string) (string, error) {
 	date := time.Now().Format("20060102")
 	hash := fmt.Sprintf("%x", sha256.Sum256([]byte(temp)))[:8]
-	return fmt.Sprintf("/__assistants/%s/%s/%s", ast.ID, date, hash), nil
+	return fmt.Sprintf("/__assistants/%s/%s/%s%s", ast.ID, date, hash, ext), nil
 }
 
 func (ast *OpenAI) allowed(contentType string) bool {
@@ -97,3 +97,43 @@ func (ast *OpenAI) FileContent() {}
 
 // FileInfo get the information of a file
 func (ast *OpenAI) FileInfo() {}
+
+// Download downloads a file
+func (ast *OpenAI) Download(ctx context.Context, fileID string) (*assistant.FileResponse, error) {
+
+	// Get the data filesystem
+	data, err := fs.Get("data")
+	if err != nil {
+		return nil, fmt.Errorf("get filesystem error: %s", err.Error())
+	}
+
+	// Check if file exists
+	exists, err := data.Exists(fileID)
+	if err != nil {
+		return nil, fmt.Errorf("check file error: %s", err.Error())
+	}
+	if !exists {
+		return nil, fmt.Errorf("file %s not found", fileID)
+	}
+
+	// Open the file
+	reader, err := data.ReadCloser(fileID)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get content type and extension
+	ext := filepath.Ext(fileID)
+
+	// Get content type from mime type
+	contentType := "application/octet-stream"
+	if v, err := data.MimeType(fileID); err == nil {
+		contentType = v
+	}
+
+	return &assistant.FileResponse{
+		Reader:      reader,
+		ContentType: contentType,
+		Extension:   ext,
+	}, nil
+}
diff --git a/neo/assistant/types.go b/neo/assistant/types.go
index 3e338cb0..03930582 100644
--- a/neo/assistant/types.go
+++ b/neo/assistant/types.go
@@ -10,6 +10,7 @@ import (
 type API interface {
 	Chat(ctx context.Context, messages []map[string]interface{}, option map[string]interface{}, cb func(data []byte) int) error
 	Upload(ctx context.Context, file *multipart.FileHeader, reader io.Reader, option map[string]interface{}) (*File, error)
+	Download(ctx context.Context, fileID string) (*FileResponse, error)
 }
 
 // Prompt a prompt
@@ -46,3 +47,10 @@ type File struct {
 	Filename    string `json:"filename"`
 	ContentType string `json:"content_type"`
 }
+
+// FileResponse represents a file download response
+type FileResponse struct {
+	Reader      io.ReadCloser
+	ContentType string
+	Extension   string
+}
diff --git a/neo/neo.go b/neo/neo.go
index 6a87be8a..50ca4c3b 100644
--- a/neo/neo.go
+++ b/neo/neo.go
@@ -94,6 +94,30 @@ func (neo *DSL) Upload(ctx Context, c *gin.Context) (*assistant.File, error) {
 	return ast.Upload(ctx, tmpfile, reader, option)
 }
 
+// Download downloads a file
+func (neo *DSL) Download(ctx Context, c *gin.Context) (*assistant.FileResponse, error) {
+	// Get file_id from query string
+	fileID := c.Query("file_id")
+	if fileID == "" {
+		return nil, fmt.Errorf("file_id is required")
+	}
+
+	// Get assistant_id from context or query
+	res, err := neo.HookCreate(ctx, []map[string]interface{}{}, c)
+	if err != nil {
+		return nil, err
+	}
+
+	// Select Assistant
+	ast, err := neo.selectAssistant(res.AssistantID)
+	if err != nil {
+		return nil, err
+	}
+
+	// Download file using the assistant
+	return ast.Download(ctx.Context, fileID)
+}
+
 // chat chat with AI
 func (neo *DSL) chat(ast assistant.API, ctx Context, messages []map[string]interface{}, c *gin.Context) error {