---
title: "POST /cas"
method: POST
path: "/cas"
tags: ["Content Addressed Storage"]
---

# POST /cas

`POST /cas`

## Response `200`

Success

- CASWriteResponse
  - `hash` string — Hash of data written to CAS

## Other responses

- `400` — Bad Request
- `401` — Unauthorized
- `500` — Server Error

## Changes

- **2020-07-05** `92900873f664` — 1 warning, 1 info
  - deleted the `header` request parameter `Content-Type`
  - added optional request body
- **2020-05-13** `415656f000a5` — 1 breaking, 1 info
  - api path removed without deprecation
  - endpoint added
- **2020-05-13** `487c5566021b` — 1 breaking, 1 info
  - api path removed without deprecation
  - endpoint added

[Change history](https://skmtc.dev/decentralized-identity/apis/sidetree-rest-api/changes/cas/post.md)

---

[API](https://skmtc.dev/decentralized-identity/apis/sidetree-rest-api.md) · [All operations](https://skmtc.dev/decentralized-identity/apis/sidetree-rest-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/decentralized-identity/sidetree-rest-api/revisions/9a32549ab92a/schema)