File Upload using URL (for all file types)

When working with files like audio, images, videos, PDFs, or documents in your workflows, you often need to fetch them from a URL and upload them via an API. Since direct binary data isn’t always supported in APIs, viaSocket uses a standard approach: fetch → convert to base64 → send as JSON.

Why Base64?

APIs commonly accept base64-encoded files instead of raw binaries. This allows files to be:

• Embedded in JSON payloads

• Easily transmitted across APIs

• Supported in actions like transcription, classification, extraction, and more

Supported File Types

This approach works for:

• 🎧 Audio – MP3, WAV, OGG

• 🖼️ Images – PNG, JPG, GIF

• 🎬 Videos – MP4, MOV, AVI

• 📄 PDFs

• 📁 Documents – DOCX, XLSX, PPTX

• 📦 Archives – ZIP, RAR

• 🧠 Other binaries – firmware, installers

How It Works (in 4 steps)

1. Fetch File from URL

Use Axios to download the file in binary format:

const fileResponse = await axios.get(fileUrl, { responseType: 'arraybuffer' }); 

2. Convert File to Base64

Convert the binary data to base64:

const base64File = Buffer.from(fileResponse.data).toString('base64'); 

3. Prepare API Payload

Wrap the base64 in your request payload:

const payload = { data: base64File }; 

4. Send File to API

Send the payload to the API endpoint:

const apiResponse = await axios.post('https://api.example.com/v1/upload', payload, {   headers: {     'Authorization': 'Bearer YOUR_API_KEY',     'Content-Type': 'application/json',   }, }); 

Use Case: Audio Upload for Transcription (ChatGPT)

const audioUrl = context?.inputData?.url; const audioResponse = await axios.get(audioUrl, { responseType: 'arraybuffer' }); const base64str = Buffer.from(audioResponse.data).toString('base64');  const payload = {   model: 'gpt-4o-audio-preview',   modalities: ['text'],   messages: [     {       role: 'user',       content: [         { type: 'text', text: 'Please transcribe this audio recording.' },         { type: 'input_audio', input_audio: { data: base64str, format: 'mp3' } }       ]     }   ],   store: true, };  const apiResponse = await axios.post('https://api.openai.com/v1/chat/completions', payload, {   headers: { 'Content-Type': 'application/json' }, });  return {   Result: apiResponse.data.choices[0].message.content,   ID: apiResponse.data.id,   Created: new Date(apiResponse.data.created * 1000).toLocaleString(),   Model: apiResponse.data.model, }; 

Optional: Filter by Execution Time (for Scheduled Triggers)

To upload only recent files, you can filter data based on when the trigger was executed:

const minutesAgo = new Date(__executionStartTime__ - context?.inputData?.scheduledTime * 60 * 1000); 

This calculates the time X minutes before the trigger ran.