Loader - local file

Overview

Local file loader is an implementation of the Document Loader interface that loads content from the local filesystem. It follows Eino: Document Loader Guide.

Features

  • Load documents by file path
  • Auto-detect file type and choose a suitable parser (requires ExtParser)
  • Preserve file metadata
  • Support using filename as document ID

Usage

Initialization

import (
    "github.com/cloudwego/eino/components/document/loader/file"
)

func main() {
    loader, err := file.NewFileLoader(ctx, &FileLoaderConfig{
        UseNameAsID: true,                // whether to use filename as document ID
        Parser:      &parser.TextParser{}, // optional: custom parser
    })
}

Parameters:

  • UseNameAsID: whether to use filename as document ID
  • Parser: document parser; if not set, default extension parser (ExtParser, currently TextParser) is used

Load Documents

docs, err := loader.Load(ctx, document.Source{ URI: "./path/to/document.txt" })

After load, the following metadata is added:

  • _file_name: filename
  • _extension: file extension
  • _source: full file path

Notes:

  • Path must point to a file, not a directory
  • File must be readable
  • If UseNameAsID is true: single file uses filename; multiple docs use filename_index

Complete Example

package main

import (
    "context"

    file "github.com/cloudwego/eino-ext/components/document/loader/file"
    "github.com/cloudwego/eino/components/document"
)

func main() {
    ctx := context.Background()

    loader, err := file.NewFileLoader(ctx, &file.FileLoaderConfig{ UseNameAsID: true })
    if err != nil { panic(err) }

    docs, err := loader.Load(ctx, document.Source{ URI: "./documents/sample.txt" })
    if err != nil { panic(err) }

    for _, doc := range docs {
        println(doc.Content)
        fileName := doc.MetaData[file.MetaKeyFileName]
        extension := doc.MetaData[file.MetaKeyExtension]
        source := doc.MetaData[file.MetaKeySource]
    }
}

References


Last modified December 16, 2025 : fix: improve readability of websocket and swagger docs (#1480) (f63ff55)