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

# Get information about an existing backup.

`GET /_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/get.ts> (a function with typed inputs; its response is checked against the schema)

Get information about an existing backup.

## Path parameters

- `version` string, required

## Response `200`

The information about the requested backup.

- object
  - `algorithm` 'm.megolm_backup.v1.curve25519-aes-sha2', required: The algorithm used for storing backups.
  - `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.
  - `count` integer, required: The number of keys stored in the backup.
  - `etag` string, required: An opaque string representing stored keys in the backup. Clients can compare it with the `etag` value they received in the request of their last key storage request. If not equal, another client has modified the backup.
  - `version` string, required: The backup version.

## Other responses

- `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)