---
title: "Create a new custom file from a cached S3 upload"
method: POST
path: "/custom_files"
tags: ["Custom Files"]
---

# Create a new custom file from a cached S3 upload

`POST /custom_files`

The Custom Files API endpoint allows you to upload PDFs to DocSpring and then
merge them with other PDFs. First upload your file using the presigned URL endpoint,
then use the returned cache_id to create the custom file.

## Request body

- object
  - `cache_id` string, required

## Response `201`

returns the custom file

- object
  - `status` 'success' | 'error', required
  - `custom_file` CustomFile, required
    - `id` string, nullable, required
    - `url` string, nullable, required
  - `errors` string[]

## Other responses

- `401` — authentication failed

---

[API](https://skmtc.dev/docspring/apis/docspring-api.md) · [All operations](https://skmtc.dev/docspring/apis/docspring-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/docspring/docspring-api/revisions/5726657b9432/schema)