---
title: "Update information about an existing backup."
method: PUT
path: "/_matrix/client/v3/room_keys/version/{version}"
tags: ["End-to-end encryption"]
---

# Update information about an existing backup.

`PUT /_matrix/client/v3/room_keys/version/{version}`

## Request

- Base URL: `https://matrix.org`
- URL: `https://matrix.org/_matrix/client/v3/room_keys/version/{version}`
- Auth: one of:
  - API key in query parameter `access_token`
  - HTTP bearer
- TypeScript: <https://skmtc.dev/matrix/apis/matrix-client-server-api/docs/_matrix/client/v3/room_keys/version/:version/put.ts> (a function with typed inputs; its response is checked against the schema)

Update information about an existing backup.  Only `auth_data` can be modified.

## Path parameters

- `version` string, required

## Request body

- object
  - `algorithm` 'm.megolm_backup.v1.curve25519-aes-sha2', required: The algorithm used for storing backups. Must be the same as the algorithm currently used by the backup.
  - `auth_data` object, required: Algorithm-dependent data. See the documentation for the backup algorithms in [Server-side key backups](https://spec.matrix.org/v1.19/client-server-api/#server-side-key-backups) for more information on the expected format of the data.
  - `version` string: The backup version. If present, must be the same as the version in the path parameter.

## Response `200`

The update succeeded.

- object

## Other responses

- `400`: A parameter was incorrect. For example, the `algorithm` does not match the current backup algorithm, or the `version` in the body does not match the `version` in the path.
- `404`: The backup specified does not exist.
- `429`: This request was rate-limited.

---

[API](https://skmtc.dev/matrix/apis/matrix-client-server-api.md) - [All operations](https://skmtc.dev/matrix/apis/matrix-client-server-api/llms.txt) - [OpenAPI document](https://skmtc.dev/matrix/apis/matrix-client-server-api/revisions/c7fe4072c681?raw)