> ## Documentation Index
> Fetch the complete documentation index at: https://cosmos-docs-cosmjs-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Offline Signers

> The OfflineSigner interface and the two Cosmos signing modes

An `OfflineSigner` is the interface CosmJS uses to abstract over *any* source of
signatures. It doesn't matter whether the private key lives in memory, in a
browser extension, or on a hardware device — as long as it implements
`OfflineSigner`, it works with `SigningStargateClient`.

```typescript theme={"system"}
type OfflineSigner = OfflineAminoSigner | OfflineDirectSigner;
```

There are two flavors, matching the two Cosmos signing modes:

## OfflineDirectSigner (Protobuf / Direct)

The modern default. Signs raw Protobuf-encoded bytes. Preferred for new
applications.

```typescript theme={"system"}
interface OfflineDirectSigner {
  readonly getAccounts: () => Promise<readonly AccountData[]>;
  readonly signDirect: (
    signerAddress: string,
    signDoc: SignDoc,
  ) => Promise<DirectSignResponse>;
}
```

## OfflineAminoSigner (Amino JSON)

The legacy format. Signs a deterministic JSON representation. Required for
Ledger hardware wallets and some older chains.

```typescript theme={"system"}
interface OfflineAminoSigner {
  readonly getAccounts: () => Promise<readonly AccountData[]>;
  readonly signAmino: (
    signerAddress: string,
    signDoc: StdSignDoc,
  ) => Promise<AminoSignResponse>;
}
```

The "offline" in the name means the signer itself never needs network access. It
only receives bytes and returns a signature. The client handles everything
else — querying account state, building the transaction, and broadcasting.

## Signer Summary

| Signer                            | Use Case                     | Package                 |
| --------------------------------- | ---------------------------- | ----------------------- |
| `DirectSecp256k1HdWallet`         | Scripts, backends, tests     | `@cosmjs/proto-signing` |
| `Secp256k1HdWallet`               | Amino signing, legacy chains | `@cosmjs/amino`         |
| `window.keplr.getOfflineSigner()` | Browser apps with Keplr      | (provided by extension) |
| `LedgerSigner`                    | Hardware wallet signing      | `@cosmjs/ledger-amino`  |

All of these produce an `OfflineSigner`. All of them work with
`SigningStargateClient.connectWithSigner`. The signing client doesn't know or
care where the signature comes from — it just needs something that implements
the interface.