---
search:
  tags:
    - Assets
    - POST
seo:
  description: >-
    Reserves an Asset and returns a presigned PUT URL to upload the bytes to.
    The URL is… Reference for the POST /assets/uploads endpoint in the AdCrunch
    API.
sidebar:
  label: Reserve an Asset and mint an upload URL
  badge: POST
title: Reserve an Asset and mint an upload URL
type: openapi-operation
---
Reserves an Asset and returns a presigned `PUT` URL to upload the bytes to. The URL is valid for one hour, and `expiresAt` says when it stops being accepted.

The client uploads **directly** to storage — the bytes never pass through this worker, because Cloudflare rejects over-limit request bodies at the proxy before any code runs. Call `POST /assets/{id}/finalize` once the upload completes.

The URL is the credential: anyone holding it can write that one key until it expires. Nothing is known about the file until finalize inspects what actually landed, so size and type cannot be enforced here.

The reserved Asset stays `pending` until finalize. No read, rename or list answers a `pending` Asset, and a reservation nobody finalizes is swept a day later, together with whatever landed under it.

`POST /assets/uploads`