Update Attachment in Knowledge Folder

Update a file in a knowledge folder

curl --request PATCH \
  --url https://api.langdock.com/knowledge/{folderId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file' \
  --form 'url=<string>' \
  --form 'attachmentId=<string>'

import requests

url = "https://api.langdock.com/knowledge/{folderId}"

files = { "file": ("example-file", open("example-file", "rb")) }
payload = {
    "url": "<string>",
    "attachmentId": "<string>"
}
headers = {"Authorization": "Bearer <token>"}

response = requests.patch(url, data=payload, files=files, headers=headers)

print(response.text)

const form = new FormData();
form.append('file', '<string>');
form.append('url', '<string>');
form.append('attachmentId', '<string>');

const options = {method: 'PATCH', headers: {Authorization: 'Bearer <token>'}};

options.body = form;

fetch('https://api.langdock.com/knowledge/{folderId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.langdock.com/knowledge/{folderId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: multipart/form-data"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.langdock.com/knowledge/{folderId}"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--")

	req, _ := http.NewRequest("PATCH", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.patch("https://api.langdock.com/knowledge/{folderId}")
  .header("Authorization", "Bearer <token>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.langdock.com/knowledge/{folderId}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--"

response = http.request(request)
puts response.read_body

{
  "message": "The file \"updated-report.pdf\" is declared as a PDF but its content does not start with the expected PDF header.",
  "code": "BAD_REQUEST"
}

{
  "message": "The provided API key is invalid."
}

{
  "message": "Knowledge folder not shared with this API key. Please share the folder with the API key in the Langdock App to upload or update files.",
  "code": "FORBIDDEN"
}

{
  "message": "Attachment with ID '550e8400-e29b-41d4-a716-446655440000' not found in this knowledge folder.",
  "code": "NOT_FOUND"
}

{
  "message": "Upload request timed out. Please try again with a smaller file or check your connection.",
  "code": "REQUEST_TIMEOUT"
}

{
  "message": "File size exceeds the maximum allowed size of 256MB. Please upload a smaller file.",
  "code": "PAYLOAD_TOO_LARGE"
}

{
  "message": "You have exceeded the maximum number of requests per minute (50)",
  "code": "TOO_MANY_REQUESTS"
}

{
  "message": "Internal server error"
}

{
  "message": "Storage capacity exceeded. Please contact your administrator.",
  "code": "SERVICE_UNAVAILABLE"
}

PATCH

knowledge

{folderId}

Update a file in a knowledge folder

curl --request PATCH \
  --url https://api.langdock.com/knowledge/{folderId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file' \
  --form 'url=<string>' \
  --form 'attachmentId=<string>'

import requests

url = "https://api.langdock.com/knowledge/{folderId}"

files = { "file": ("example-file", open("example-file", "rb")) }
payload = {
    "url": "<string>",
    "attachmentId": "<string>"
}
headers = {"Authorization": "Bearer <token>"}

response = requests.patch(url, data=payload, files=files, headers=headers)

print(response.text)

const form = new FormData();
form.append('file', '<string>');
form.append('url', '<string>');
form.append('attachmentId', '<string>');

const options = {method: 'PATCH', headers: {Authorization: 'Bearer <token>'}};

options.body = form;

fetch('https://api.langdock.com/knowledge/{folderId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.langdock.com/knowledge/{folderId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: multipart/form-data"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.langdock.com/knowledge/{folderId}"

	payload := strings.NewReader("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--")

	req, _ := http.NewRequest("PATCH", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.patch("https://api.langdock.com/knowledge/{folderId}")
  .header("Authorization", "Bearer <token>")
  .body("-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.langdock.com/knowledge/{folderId}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request.body = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"file\"; filename=\"example-file\"\r\nContent-Type: application/octet-stream\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"url\"\r\n\r\n<string>\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"attachmentId\"\r\n\r\n<string>\r\n-----011000010111000001101001--"

response = http.request(request)
puts response.read_body

{
  "message": "The file \"updated-report.pdf\" is declared as a PDF but its content does not start with the expected PDF header.",
  "code": "BAD_REQUEST"
}

{
  "message": "The provided API key is invalid."
}

{
  "message": "Knowledge folder not shared with this API key. Please share the folder with the API key in the Langdock App to upload or update files.",
  "code": "FORBIDDEN"
}

{
  "message": "Attachment with ID '550e8400-e29b-41d4-a716-446655440000' not found in this knowledge folder.",
  "code": "NOT_FOUND"
}

{
  "message": "Upload request timed out. Please try again with a smaller file or check your connection.",
  "code": "REQUEST_TIMEOUT"
}

{
  "message": "File size exceeds the maximum allowed size of 256MB. Please upload a smaller file.",
  "code": "PAYLOAD_TOO_LARGE"
}

{
  "message": "You have exceeded the maximum number of requests per minute (50)",
  "code": "TOO_MANY_REQUESTS"
}

{
  "message": "Internal server error"
}

{
  "message": "Storage capacity exceeded. Please contact your administrator.",
  "code": "SERVICE_UNAVAILABLE"
}

Updates an existing file (attachment) in a Knowledge base by replacing it with a new version. The old file is removed and the new file is processed and embedded.

Before You Start

API key scope: Requires an API key with the KNOWLEDGE_FOLDER_API scope. The API key itself needs the Editor role on the Knowledge base. See Share Knowledge bases with the API for setup instructions.
Knowledge bases: The Knowledge Folder API manages resources that appear as Knowledge bases in the Library.

Base URL

https://api.langdock.com

Dedicated deploymentsReplace api.langdock.com with <your-deployment-url>/api/public in all requests.

Request Format

This endpoint accepts multipart/form-data requests with the file attached.

Path Parameters

Parameter	Type	Required	Description
`folderId`	string	Yes	The ID of the Knowledge base

Form Fields

Field	Type	Required	Description
`attachmentId`	string	Yes	The ID of the attachment to update
`file`	file	Yes	The new file to upload. See size limits below.
`url`	string	No	URL shown to users when this file is used in an answer

File size limits depend on the file type: 10 MB for plain text, Markdown, JSON, and VTT files; 30 MB for XML files; and 256 MB for other supported document types. See the supported file types reference for supported formats.

Examples

Update with cURL

curl -X PATCH "https://api.langdock.com/knowledge/{folderId}" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "attachmentId=att_abc123def456" \
  -F "file=@/path/to/new-document.pdf"

Update with JavaScript

const FormData = require("form-data");
const fs = require("fs");
const axios = require("axios");

async function updateAttachment(folderId, attachmentId, filePath) {
  const form = new FormData();
  form.append("attachmentId", attachmentId);
  form.append("file", fs.createReadStream(filePath));

  const response = await axios.patch(
    `https://api.langdock.com/knowledge/${folderId}`,
    form,
    {
      headers: {
        Authorization: "Bearer YOUR_API_KEY",
        ...form.getHeaders(),
      },
    }
  );

  return response.data;
}

// Example usage
try {
  const result = await updateAttachment(
    "folder_abc123",
    "att_xyz789",
    "/path/to/updated-report.pdf"
  );
  console.log("Attachment updated:", result);
} catch (error) {
  console.error("Failed to update:", error.response?.data?.message);
}

Update with Source URL

const FormData = require("form-data");
const fs = require("fs");
const axios = require("axios");

async function updateAttachmentWithUrl(folderId, attachmentId, filePath, sourceUrl) {
  const form = new FormData();
  form.append("attachmentId", attachmentId);
  form.append("file", fs.createReadStream(filePath));
  form.append("url", sourceUrl);

  const response = await axios.patch(
    `https://api.langdock.com/knowledge/${folderId}`,
    form,
    {
      headers: {
        Authorization: "Bearer YOUR_API_KEY",
        ...form.getHeaders(),
      },
    }
  );

  return response.data;
}

Response Format

Success Response (200 OK)

{
  status: "success";
  result: {
    id: string;          // Unique attachment ID
    name: string;        // Original filename
    mimeType: string;    // MIME type of the file
    createdAt: string;   // ISO 8601 timestamp
    updatedAt: string;   // ISO 8601 timestamp
    url: string | null;  // Source URL if provided
  };
}

Example Response

{
  "status": "success",
  "result": {
    "id": "att_abc123def456",
    "name": "updated-report.pdf",
    "mimeType": "application/pdf",
    "createdAt": "2025-01-15T10:30:00.000Z",
    "updatedAt": "2025-01-20T14:45:00.000Z",
    "url": null
  }
}

File Validation Response (400 Bad Request)

If the replacement file fails validation, the API returns the reason in message:

{
  "message": "The file \"updated-report.pdf\" is declared as a PDF but its content does not start with the expected PDF header.",
  "code": "BAD_REQUEST"
}

Error Handling

try {
  const response = await updateAttachment(folderId, attachmentId, filePath);
} catch (error) {
  if (error.response) {
    console.error(error.response.data.message ?? "Update failed");
  }
}

Status	Meaning
`400`	Invalid request or file validation failure
`401`	Invalid or missing API key
`403`	API key does not have access to the Knowledge base
`404`	Knowledge base or attachment not found
`408`	Upload timed out
`413`	File exceeds the size limit
`429`	Rate limit exceeded
`500`	Unexpected server error
`503`	Storage capacity exceeded

Processing Status

After updating, the new file is processed asynchronously. Use the Retrieve Files endpoint to check processing status. The syncStatus field indicates the current state:

UPLOADING - File is being uploaded
UPLOADED - File is uploaded and queued for processing
EXTRACTING - Text is being extracted from the file
EMBEDDING - Embeddings are being generated
SYNCED - File is ready for search
ACTION_FAILED, EXTRACTION_FAILED, EMBEDDING_FAILED, TIMEOUT - Processing failed

Langdock intentionally blocks browser-origin requests to protect your API key and ensure your applications remain secure. For more information, please see our guide on API Key Best Practices.

Authorizations

Authorization

string

header

required

API key as Bearer token. Format "Bearer YOUR_API_KEY"

Path Parameters

folderId

string

required

The ID of the knowledge folder

Body

multipart/form-data

file

The new file to upload

url

string

URL that is shown to the user if the file is used in an answer

attachmentId

string

The ID of the attachment to update

Response

Attachment updated successfully

⌘I

Overview

Completion API

Embedding API

Agents API

Assistants API (Deprecating)

Integrations API

Skills API

Knowledge Folder API

Usage Export API

Workflow Run Export API

User Management API

Audit Logs API

Update Attachment in Knowledge Folder

Before You Start

Base URL

Request Format

Path Parameters

Form Fields

Examples

Update with cURL

Update with JavaScript

Update with Source URL

Response Format

Success Response (200 OK)

Example Response

File Validation Response (400 Bad Request)

Error Handling

Processing Status

Authorizations

Path Parameters

Body

Response

​Before You Start

​Base URL

​Request Format

​Path Parameters

​Form Fields

​Examples

​Update with cURL

​Update with JavaScript

​Update with Source URL

​Response Format

​Success Response (200 OK)

​Example Response

​File Validation Response (400 Bad Request)

​Error Handling

​Processing Status

Authorizations

Path Parameters

Body

Response

Before You Start

Base URL

Request Format

Path Parameters

Form Fields

Examples

Update with cURL

Update with JavaScript

Update with Source URL

Response Format

Success Response (200 OK)

Example Response

File Validation Response (400 Bad Request)

Error Handling

Processing Status