Create an upload session

Info: This documentent primarily focuses on library authors. If you want to integrate Lancer into your application please checkout SDK & Packages page

Every file upload starts with a session in Lancer. Basically Lancer handle things in chunks by default.

Prerequisites

Before you start, ensure the following:

• Lancer server is running and accessible.
• A file to upload

You'll also need :

• Axios : Install Axios for making HTTP requests.

  npm install axios

The first step is to create an upload session. This session will hold metadata about the file and the upload process. The server will return a sessionToken that is used for subsequent chunk uploads.

API Endpoint

POST /api/session

Request Payload

{
  "file_size": 10485760,     // File size in bytes
  "file_name": "example.txt", // Name of the file
  "max_chunk": 2,            // Total number of chunks
  "chunk_size": 5242880,     // Size of each chunk in bytes
  "provider": "LOCAL"        // Storage provider ("LOCAL" or "AWS")
}

Example Code

import axios from "axios";

const API = "http://localhost:8080"; // Base API URL
const CreateSessionEndpoint = API + "/api/sessions";

async function createUploadSession(file) {
  const baseChunkSize = 5 * 1024 * 1024; // Default chunk size: 5 MB
  const totalChunks = Math.ceil(file.size / baseChunkSize);

  const response = await axios.post(
    CreateSessionEndpoint,
    {
      file_size: file.size,
      file_name: file.name,
      max_chunk: totalChunks,
      chunk_size: baseChunkSize,
      provider: "LOCAL",
    },
    {
      headers: {
        Authorization: "Bearer <YOUR_ACCESS_TOKEN>", // Replace with a valid token
      },
    }
  );

  return response.data.sessionToken; // Extract the session token
}