Signer

The main purpose of the @interchainjs/cosmos, @interchainjs/ethereum, @interchainjs/injective is to offer developers a way to have different Signer implementations on different types of Blockchains. All of these Signers are implementing UniSigner interface and extending the same BaseSigner class which with Auth object being utilized in construction.

Class diagram:

Workflow:

import { UniSigner } from "@interchainjs/types";
import { BaseSigner } from "@interchainjs/types";

Need to note that there are 2 type parameters that indicates 2 types of document involved in signing and broadcasting process for interface UniSigner:

• SignDoc is the document type as the signing target to get signature
• Tx is the signed transaction type to broadcast

The Signer class is a way to sign and broadcast transactions on blockchains with ease. With it, you can just pass a Message that you want to be packed in a transaction and the transaction will be prepared, signed and broadcasted.

Signer + Auth

As we know, Auth object can be used to sign any piece of binary data (See details). However, combining with the *Signer class allows you to sign human-readable messages or transactions using one function call.

Usage

import { DirectSigner } from "@interchainjs/cosmos/signers/direct";
import { toEncoder } from "@interchainjs/cosmos/utils";
import { Secp256k1Auth } from "@interchainjs/auth/secp256k1";
import { MsgSend } from "@interchainjs/cosmos-types/cosmos/bank/v1beta1/tx";
import {
  HDPath
} from '@interchainjs/types';
 
 
const [auth] = Secp256k1Auth.fromMnemonic("<MNEMONIC_WORDS>", [
    // use cosmos hdpath built by HDPath
    // we can get cosmos hdpath "m/44'/118'/0'/0/0" by this:
    HDPath.cosmos().toString(),
]);
const signer = new DirectSigner(auth, [toEncoder(MsgSend)], <RPC_ENDPOINT>);

Signer + Wallet

Wallet object can also be used to sign documents (See details). However, some sign document is still not human-readable (i.e. for DirectSigner, the SignDoc type is an object with binary data types)

However, combining with the Signer class allows you to sign human-readable messages or transactions using one function call.

Usage

import { DirectSigner } from "@interchainjs/cosmos/signers/direct";
import { DirectWallet, SignDoc } from "@interchainjs/cosmos/types";
import { toEncoder } from "@interchainjs/cosmos/utils";
import { MsgSend } from "@interchainjs/cosmos-types/cosmos/bank/v1beta1/tx";
import { HDPath } from "@interchainjs/types";
 
const directWallet = Secp256k1HDWallet.fromMnemonic("<MNEMONIC_WORDS>", [
  {
    // bech32_prefix
    prefix: "cosmos",
    // use cosmos hdpath built by HDPath
    // we can get cosmos hdpath "m/44'/118'/0'/0/0" by this:
    hdPath: HDPath.cosmos().toString(),
  },
]);
const signer = await DirectSigner.fromWallet(wallet, [toEncoder(MsgSend)], <RPC_ENDPOINT>);

Tips: interchainjs also provides helper methods to easily construct Wallet for each Signer. See details.

UniSigner Interface

There are 3 main signing methods in UniSigner

/** you can import { UniSigner } from "@interchainjs/types" */
export interface UniSigner<SignDoc, Tx> {
  ...
  signArbitrary(data: Uint8Array): IKey;
  signDoc: (doc: SignDoc) => Promise<SignDocResponse<SignDoc>>;
  sign(
    messages: unknown,
    ...args: unknown[]
  ): Promise<SignResponse<SignDoc, Tx>>;
  ...
}

• signArbitrary, derived from Auth object, is usually used to request signatures that don't need to be efficiently processed on-chain. It's often used for signature challenges that are authenticated on a web server, such as sign-in with Ethereum/Cosmos.
• signDoc, derived from Wallet object, is usually used to request signatures that are efficient to process on-chain. The doc argument varies among different signing modes and networks.
• sign is used to sign human-readable message, to facilidate signing process with an user interface.

Tips: These 3 signing methods correspond to 3 levels of signing type: Auth vs. Wallet vs. Signer.

Types

Tips about the headers:

• Class: the Class implements the Interface
• SignDoc: document structure for signing
• Transaction: document structure for broadcasting (abbr. Tx)
• Wallet: interface for web3 wallets
• WalletAccount: interface for web3 wallets account

CosmosDirectSigner

• Class: import { DirectSigner } from "@interchainjs/cosmos/signers/direct"
• SignDoc: CosmosDirectDoc
• Transaction: CosmosTx
• Wallet: Secp256k1HDWallet
• WalletAccount: CosmosAccount

CosmosAminoSigner

• Class: import { AminoSigner } from "@interchainjs/cosmos/signers/amino"
• SignDoc: CosmosAminoDoc
• Transaction: CosmosTx
• Wallet: Secp256k1HDWallet
• WalletAccount: CosmosAccount

InjectiveDirectSigner

• Class: import { DirectSigner } from "@interchainjs/injective/direct"
• SignDoc: CosmosDirectDoc
• Transaction: CosmosTx
• Wallet:
• WalletAccount: InjectiveAccount

InjectiveAminoSigner

• Class: import { AminoSigner } from "@interchainjs/injective/amino"
• SignDoc: CosmosAminoDoc
• Transaction: CosmosTx
• Wallet:
• WalletAccount: InjectiveAccount