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POST
/
attachment
/
v1
/
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'
{
  "attachmentId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "file": {
    "name": "<string>",
    "mimeType": "<string>",
    "sizeInBytes": 123
  }
}
The Assistants API will be deprecated in a future release.For new projects, 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.
ParameterTypeRequiredDescription
fileFileYesThe 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) {
    switch (error.response.status) {
      case 400:
        console.error('No file provided');
        break;
      case 401:
        console.error('Invalid API key');
        break;
      case 500:
        console.error('Server error');
        break;
    }
  }
}
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 projects, reference the Agents API documentation:
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
file
required

The file to upload

Response

Successfully uploaded file

​
attachmentId
string<uuid>
required

Unique identifier for the uploaded attachment

​
file
object
required