I'm building a web application that requires to me to receive file binaries on a server-side endpoint, convert those binaries to FormData, then POST them to another endpoint. The second endpoint only accepts "multipart/form-data".

I'm using axios to create the requests, and NodeJS on the server.

The files are posted from the client as form data, but I'm unable to manipulate them as such once they reach the server.

How do I compel file binaries to FormData in my server-side scripts?

Client:

const handleImageSubmit = async (attachments) => {
    try {
      let image
      if (attachments.length) {
        const formData = new FormData()

        for (let i = 0; i < attachments.length; i += 1) {
          formData.append(
            `files.${attachments[i].name}`,
            attachments[i],
            attachments[i].name
          )
        }

        const config = {
          headers: { 'Content-Type': 'multipart/form-data' },
        }

        image = await axios.post(
          '/api/proxy/upload',
          formData,
          config
        )
      }
      console.log('Files dispatched to server')
    } catch (err) {
      console.error(err)
    }
  }

Server-side:

const upload = async (req, res) => {
  try {
    const data = new FormData()

   // Convert the binaries in req.body into FormData
   const myFiles = ...

    data.append('files',
      myFiles)

    const config = {
      method: 'post',
      url: `${process.env.API_URL}/upload`,
      headers: {
        Authorization: `Bearer ${req.headers['auth-token']}`,
        ...data.getHeaders()
      },
      data: data,
    }

    const signal = await axios(config)
    res.json(signal.data)

  } catch (err) {
    console.error(err)
    res.status(fetchResponse?.status || 500).json(err)
  }
}