Upload File to Knowledge Folder

Upload a new file to a Knowledge base

POST /knowledge/{folderId}

Upload a file to a knowledge folder

cURL

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

400

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

Uploads a new file to a specified Knowledge base. The file will be processed, embedded, and made available for semantic search.

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 deployments

Replace 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
file	file	Yes	The file to upload. See size limits below.
url	string	No	Optional source URL to associate with the file

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.

Supported File Types

Knowledge bases support document and text formats such as:

• PDF (.pdf)
• Word documents (.doc, .docx)
• Text files (.txt)
• Markdown (.md)
• HTML (.html)
• PowerPoint (.pptx, .ppt)

See the supported file types reference for additional formats. This endpoint rejects spreadsheet, image, audio, and video files.

Executable files and other potentially dangerous file types are blocked for security reasons.

Examples

Upload a File with cURL

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

Upload a File with JavaScript

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

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

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

  return response.data;
}

Upload with Source URL

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

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

  const response = await axios.post(
    `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": "quarterly-report.pdf",
    "mimeType": "application/pdf",
    "createdAt": "2025-01-15T10:30:00.000Z",
    "updatedAt": "2025-01-15T10:30:00.000Z",
    "url": null
  }
}

File Validation Response (400 Bad Request)

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

{
  "message": "The file \"quarterly-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 uploadFile(folderId, filePath);
} catch (error) {
  if (error.response) {
    console.error(error.response.data.message ?? "Upload 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 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 upload, the 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

Async Upload Variant

For large files or when you don’t need to wait for the upload response, you can use the async upload endpoint:

POST /knowledge/{folderId}/upload-async

This endpoint accepts the same multipart/form-data fields and returns 202 Accepted after the file is received. Processing continues in the background.

{
  "status": "processing",
  "result": {
    "id": "att_abc123def456",
    "name": "quarterly-report.pdf",
    "mimeType": "application/pdf",
    "createdAt": "2025-01-15T10:30:00.000Z",
    "updatedAt": "2025-01-15T10:30:00.000Z",
    "url": null,
    "processingStatus": "UPLOADED",
    "statusUrl": "/api/public/knowledge/{folderId}/{attachmentId}"
  },
  "message": "File uploaded successfully and is being processed in the background. Poll the statusUrl to check when processing completes (syncStatus: SYNCED)."
}

File validation happens before the API accepts the upload. If validation fails, the async endpoint returns the same 400 Bad Request response shown above instead of 202 Accepted.

Use GET {statusUrl} to poll processing status. The response returns the current status in result.syncStatus.

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 · file

The file to upload

url · string

The associated URL

Response

200

File uploaded successfully