This document describes how to configure and use the keyring and its various backends for an [**application**](../basics/app-anatomy.md). {synopsis}
The keyring holds the private/public keypairs used to interact with a node. For instance, a validator key needs to be set up before running the blockchain node, so that blocks can be correctly signed. The private key can be stored in different locations, called "backends", such as a file or the operating system's own key storage.
Make sure you can build your own binary, and replace `simd` with the name of your binary in the snippets.
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Applications developed using the Cosmos SDK come with the `keys` subcommand. For the purpose of this tutorial, we're running the `simd` CLI, which is an application built using the Cosmos SDK for testing and educational purposes. For more information, see [`simapp`](https://github.com/cosmos/cosmos-sdk/tree/v0.40.0-rc2/simapp).
You can use `simd keys` for help about the keys command and `simd keys [command] --help` for more information about a particular subcommand.
::: tip
You can also enable auto-completion with the `simd completion` command. For example, at the start of a bash session, run `. <(simd completion)`, and all `simd` subcommands will be auto-completed.
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To create a new key in the keyring, run the `add` subcommand with a `<key_name>` argument. For the purpose of this tutorial, we will solely use the `test` backend, and call our new key `my_validator`. This key will be used in the next section.
```bash
$ simd keys add my_validator --keyring-backend test
# Put the generated address in a variable for later use.
This command generates a new 24-word mnemonic phrase, persists it to the relevant backend, and outputs information about the keypair. If this keypair will be used to hold value-bearing tokens, be sure to write down the mnemonic phrase somewhere safe!
By default, the keyring generates a `secp256k1` keypair. The keyring also supports `ed25519` keys, which may be created by passing the `--algo ed25519` flag. A keyring can of course hold both types of keys simultaneously, and the Cosmos SDK's `x/auth` module (in particular its [AnteHandlers](../core/baseapp.md#antehandler)) supports natively these two public key algorithms.