Upload File

import * as wmill from "windmill-client"

import { S3Object } from "windmill-client"

/**

 * Upload File

 * Upload a file from Windmill object storage to Notion. Files over 20 MiB are sent in 10 MiB parts. Pass `attach_to_page_id` to append it to a page as a file block; otherwise use the returned `id` within an hour (as a `file_upload` in a block, cover, icon or files property) or it expires. Free workspaces cap files at 5 MiB.

 */

export async function main(

  auth: RT.Notion,

  file: S3Object,

  filename: string,

  content_type: string | undefined,

  attach_to_page_id: string | undefined

) {

  const bytes = await wmill.loadS3File(file)

  if (!bytes) {

    throw new Error("Could not load the file from object storage")

  }

  const headers = {

    Authorization: `Bearer ${auth.token}`,

    Accept: "application/json",

    "Notion-Version": "2026-03-11",

  }

  const call = async (path: string, init: RequestInit) => {

    const response = await fetch(`https://api.notion.com/v1/${path}`, {

      ...init,

      headers: { ...headers, ...init.headers },

    })

    if (!response.ok) {

      throw new Error(`${response.status} ${await response.text()}`)

    }

    return await response.json()

  }

  const PART = 10 * 1024 * 1024

  const parts =

    bytes.length > 20 * 1024 * 1024 ? Math.ceil(bytes.length / PART) : 1

  const create: { [key: string]: any } = { filename }

  if (content_type !== undefined && content_type !== "") {

    create.content_type = content_type

  }

  if (parts > 1) {

    create.mode = "multi_part"

    create.number_of_parts = parts

  }

  const upload = await call("file_uploads", {

    method: "POST",

    headers: { "Content-Type": "application/json" },

    body: JSON.stringify(create),

  })

  let result = upload

  for (let i = 0; i < parts; i++) {

    const form = new FormData()

    const chunk = parts > 1 ? bytes.subarray(i * PART, (i + 1) * PART) : bytes

    form.append(

      "file",

      new Blob([chunk], { type: content_type || undefined }),

      filename

    )

    if (parts > 1) form.append("part_number", String(i + 1))

    result = await call(`file_uploads/${upload.id}/send`, {

      method: "POST",

      body: form,

    })

  }

  if (parts > 1) {

    result = await call(`file_uploads/${upload.id}/complete`, {

      method: "POST",

    })

  }

  if (attach_to_page_id !== undefined && attach_to_page_id !== "") {

    await call(`blocks/${attach_to_page_id}/children`, {

      method: "PATCH",

      headers: { "Content-Type": "application/json" },

      body: JSON.stringify({

        children: [

          {

            type: "file",

            file: { type: "file_upload", file_upload: { id: upload.id } },

          },

        ],

      }),

    })

  }

  return result

}