api/blob-upload.js

import { put } from '@vercel/blob';

export default async function handler(req, res) {
  if (req.method !== 'PUT') {
    return res.status(405).json({ message: 'Method not allowed' });
  }

  try {
    const token = process.env.BLOB_READ_WRITE_TOKEN;
    // Prefer project credentials; if that fails and a token is present, retry with token.
    const name = (req.query.name && String(req.query.name)) || `uploads/${Date.now()}.bin`;
    const contentType = req.headers['content-type'] || 'application/octet-stream';

    // Debug logs (streaming, no buffering)
    try {
      console.log('blob-upload debug', {
        name,
        contentType,
        streamed: true,
      });
    } catch {}

    // Stream the incoming request directly to Vercel Blob to avoid buffering large files
    const baseOpts = { contentType, access: 'public', addRandomSuffix: false };

    let result;
    try {
      // Attempt using project credentials (no token) - stream request
      result = await put(name, req, baseOpts);
    } catch (e1) {
      try { console.error('blob-upload first attempt failed (no token)', e1?.message || String(e1)); } catch {}
      if (token) {
        try {
          // Fallback: attempt with provided token - stream request
          result = await put(name, req, { ...baseOpts, token });
        } catch (e2) {
          try { console.error('blob-upload second attempt failed (with token)', e2?.message || String(e2)); } catch {}
          throw e2;
        }
      } else {
        throw e1;
      }
    }

    return res.status(201).json({ url: result.url });
  } catch (error) {
    try { console.error('blob-upload error', error); } catch {}
    return res.status(500).json({ message: 'Upload failed', error: error.message || String(error) });
  }
}