Upload Attachment API

Upload an attachment

curl --request POST \
  --url https://api.langdock.com/attachment/v1/upload \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file'

import requests

url = "https://api.langdock.com/attachment/v1/upload"

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

response = requests.post(url, files=files, headers=headers)

print(response.text)

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

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

options.body = form;

fetch('https://api.langdock.com/attachment/v1/upload', 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/attachment/v1/upload",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  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--",
  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/attachment/v1/upload"

	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--")

	req, _ := http.NewRequest("POST", 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.post("https://api.langdock.com/attachment/v1/upload")
  .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--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.langdock.com/attachment/v1/upload")

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

request = Net::HTTP::Post.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--"

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

{
  "attachmentId": "550e8400-e29b-41d4-a716-446655440000",
  "file": {
    "name": "example.pdf",
    "mimeType": "application/pdf",
    "sizeInBytes": 1234567
  }
}

POST

attachment

upload

Upload an attachment

curl --request POST \
  --url https://api.langdock.com/attachment/v1/upload \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: multipart/form-data' \
  --form file='@example-file'

import requests

url = "https://api.langdock.com/attachment/v1/upload"

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

response = requests.post(url, files=files, headers=headers)

print(response.text)

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

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

options.body = form;

fetch('https://api.langdock.com/attachment/v1/upload', 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/attachment/v1/upload",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  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--",
  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/attachment/v1/upload"

	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--")

	req, _ := http.NewRequest("POST", 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.post("https://api.langdock.com/attachment/v1/upload")
  .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--")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.langdock.com/attachment/v1/upload")

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

request = Net::HTTP::Post.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--"

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

{
  "attachmentId": "550e8400-e29b-41d4-a716-446655440000",
  "file": {
    "name": "example.pdf",
    "mimeType": "application/pdf",
    "sizeInBytes": 1234567
  }
}

The Assistants API will be deprecated on 16 August.For new systems, we recommend using the Agents API. The upload attachments endpoint remains the same, but you should reference it from the Agents API documentation.See the migration guide to learn about the differences.

Upload files that can be referenced in Assistant conversations using their attachment IDs.

To use the API you need an API key. You can create API Keys in your Workspace settings.

Request Format

This endpoint accepts multipart/form-data requests with a single file upload.

Parameter	Type	Required	Description
`file`	File	Yes	The file you want to upload

Response Format

The API returns the uploaded file information:

{
  attachmentId: string;
  file: {
    name: string;
    mimeType: string;
    sizeInBytes: number;
  }
}

Example

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

async function uploadAttachment() {
  const form = new FormData();
  form.append("file", fs.createReadStream("example.pdf"));

  const response = await axios.post(
    "https://api.langdock.com/attachment/v1/upload",
    form,
    {
      headers: {
        ...form.getHeaders(),
        Authorization: "Bearer YOUR_API_KEY",
      },
    }
  );

  console.log(response.data);
  // {
  //   attachmentId: "550e8400-e29b-41d4-a716-446655440000",
  //   file: {
  //     name: "example.pdf",
  //     mimeType: "application/pdf",
  //     sizeInBytes: 1234567
  //   }
  // }
}

Error Handling

try {
  const response = await axios.post('https://api.langdock.com/attachment/v1/upload', ...);
} catch (error) {
  if (error.response) {
    const { data } = error.response;
    console.error(data.message ?? data.error ?? "Upload failed");
  }
}

Upload errors

Status	Meaning	Reason field
`400`	Invalid request or failed file validation	`message`, or `error` if no file was provided
`401`	Invalid or missing API key	`message`
`403`	API key is missing the required scope	`message`
`406`	Blocked file type	`message`
`413`	File exceeds the size limit	`message`
`429`	Rate limit exceeded	`message`
`500`	Unexpected server error	`message`

A file content validation error returns:

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

Use the attachment

The uploaded attachment ID can be used in the Assistant API by including it in the attachmentIds array either at the assistant level or message level.

Migrating to Agents API

The upload attachment endpoint remains the same across both APIs. For new systems, reference the Agents API documentation:

Agent Upload Attachments API

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"

Body

multipart/form-data

file

required

The file to upload

Response

Successfully uploaded file

attachmentId

string<uuid>

required

Unique identifier for the uploaded attachment

Example:

"550e8400-e29b-41d4-a716-446655440000"

file

object

required

Show child attributes

Models for Assistant API Assistant Migration Guide

⌘I

Overview

Completion API

Embedding API

Agents API

Assistants API (Deprecating)

Integrations API

Skills API

Knowledge Folder API

Usage Export API

User Management API

Audit Logs API

Upload Attachment API

Request Format

Response Format

Example

Error Handling

Upload errors

Use the attachment

Migrating to Agents API

Authorizations

Body

Response

​Request Format

​Response Format

​Example

​Error Handling

​Upload errors

​Use the attachment

​Migrating to Agents API

Authorizations

Body

Response

Request Format

Response Format

Example

Error Handling

Upload errors

Use the attachment

Migrating to Agents API