---
title: "Start a browser-driven S3 multipart upload"
method: POST
path: "/v1/upload/multipart"
tags: ["Upload"]
---

# Start a browser-driven S3 multipart upload

`POST /v1/upload/multipart`

## Request

- Base URL: `https://api.picsha.ai`
- URL: `https://api.picsha.ai/v1/upload/multipart`
- Auth: HTTP bearer

## Headers

- `x-org-id` string
- `x-external-user-id` string

## Request body

- object
  - `filename` string, required: Original filename (kept for the caller; the key is random)
  - `contentType` string, required: MIME type of the file
  - `size` integer: Total size in bytes, informational

## Response `200`

Default Response

- object
  - `key` string, required
  - `uploadId` string, required

## Other responses

- `500`: Default Response

---

[API](https://skmtc.dev/picsha/apis/picsha-ai-api.md) · [All operations](https://skmtc.dev/picsha/apis/picsha-ai-api/llms.txt) · [OpenAPI document](https://skmtc.dev/picsha/apis/picsha-ai-api/revisions/f77c6ac40e70?raw)