---
title: "Start a multipart upload directly to S3."
method: POST
path: "/api/v1/documents/init_multipart_upload"
---

# Start a multipart upload directly to S3.

`POST /api/v1/documents/init_multipart_upload`

## Request

- Base URL: `https://app.onecodex.com`
- URL: `https://app.onecodex.com/api/v1/documents/init_multipart_upload`
- Auth: API key in header `X-API-Key`

## Response `200`

OK

- object
  - `callback_url` string, required
  - `file_id` string, required
  - `import_as_document` boolean, required
  - `s3_bucket` string, required
  - `upload_aws_access_key_id` string, required
  - `upload_aws_secret_access_key` string, required

## Changes

- **2026-11-03** `3be5a5f9bf7d`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/onecodex/apis/one-codex-api-v1/changes/api/v1/documents/init_multipart_upload/post.md)

---

[API](https://skmtc.dev/onecodex/apis/one-codex-api-v1.md) - [All operations](https://skmtc.dev/onecodex/apis/one-codex-api-v1/llms.txt) - [OpenAPI document](https://skmtc.dev/onecodex/apis/one-codex-api-v1/revisions/3be5a5f9bf7d?raw)