Create Presigned Upload - Dreep API Documentation

Returns a short-lived URL to PUT the file bytes to. The file never passes through the Dreep API, which is what makes this the right path for large files — and the only safe way to upload from a browser, since your API key stays on your server.

const upload = await dreep.presignUpload({
  filename: "video.mp4",
  contentType: "video/mp4",
  sizeBytes: 84_000_000,
  folder: "uploads/2026",
});

Parameters

Parameter	Type	Description
`contentType`	`string`	Required. MIME type of the file
`sizeBytes`	`number`	Required. Exact size in bytes
`filename`	`string`	Optional when `key` supplies the name
`folder`	`string`	Slug path of the destination. Missing folders are created
`key`	`string`	Full S3-style object key
`folderId`	`string`	UUID of an existing folder
`autoCreateFolders`	`boolean`	Set `false` to require the path already exists
`format`	`string`	Target format to re-encode to on confirm
`presetKey`	`string`	A saved preset, applied on confirm
`contentHash`	`string`	SHA-256 of the file — lets Dreep skip content it already has
`signal`	`AbortSignal`	Cancels the request

Returns

{
  id: "2f928a3f-1d2a-4a2b",
  uploadUrl: "https://…",   // absent when alreadyExists is true
  contentType: "video/mp4",
  alreadyExists: false,
}

The full flow

// 1. On your server
const upload = await dreep.presignUpload({ filename, contentType, sizeBytes });

// 2. Anywhere, including the browser
await fetch(upload.uploadUrl, { method: "PUT", body: file });

// 3. On your server
const asset = await dreep.confirmUpload({ id: upload.id });

Until confirmUpload() is called the asset stays pending and is excluded from media listings.

The PUT must use the exact contentType and sizeBytes you presigned with — the signature covers both. See Uploading Media for the underlying HTTP flow.

Skipping duplicate uploads

Pass the file’s SHA-256 as contentHash. If Dreep already stores that content, the response comes back with alreadyExists: true and no uploadUrl — skip the PUT.

const upload = await dreep.presignUpload({ contentType, sizeBytes, contentHash });

if (!upload.alreadyExists) {
  await fetch(upload.uploadUrl!, { method: "PUT", body: file });
}

const asset = await dreep.confirmUpload({ id: upload.id });