---
title: "Create Multipart Part Urls"
method: POST
path: "/users/assets/multipart/part_urls"
tags: ["accepts-api-key"]
---

# Create Multipart Part Urls

`POST /users/assets/multipart/part_urls`

## Request

- Base URL: `https://api.tellers.ai` (the document declares no server; this is the origin it was published from)
- URL: `https://api.tellers.ai/users/assets/multipart/part_urls`
- Auth: none declared

Presign fresh part URLs for an in-flight multipart upload.

Called as the upload progresses, so a part is always sent with a URL minted
moments before, and a part rejected with 403 can be retried with a new one.

## Headers

- `x-api-key` string, nullable
- `authorization` string, nullable

## Request body

- MultipartPartUrlsRequest
  - `asset_id` string, required
  - `multipart_upload_id` string, required
  - `part_numbers` integer[], required: 1-based part numbers to presign. Request them as the upload progresses instead of relying on the URLs returned by upload_urls: those are signed with temporary credentials, so they can expire long before a large upload reaches its last parts.

## Response `200`

Successful Response

- MultipartPartUrlsResponse
  - `urls` MultipartPartUrl[], required
    - `part_number` integer, required
    - `url` string, required

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/tellers/apis/tellers-api.md) - [All operations](https://skmtc.dev/tellers/apis/tellers-api/llms.txt) - [OpenAPI document](https://skmtc.dev/tellers/apis/tellers-api/revisions/fdaa0fa44a26?raw)