Writing a Custom Adapter

Every wallet in XRPL Wallet Kit is implemented as an adapter — a small object that wraps the wallet's native SDK behind a unified interface. If your target wallet isn't in the official list, you can write your own.

Adapter interface

An adapter must implement WalletAdapter from @xrpl-wallet-kit/core:

import type { WalletAdapter } from "@xrpl-wallet-kit/core";

const myAdapter: WalletAdapter = {
  id: "my-wallet",
  name: "My Wallet",
  icon: "https://my-wallet.io/logo.png",

  async connect(context) { /* ... */ },
  async disconnect() { /* ... */ },
  async signTransaction(txJson, context) { /* ... */ },

  // Optional but recommended:
  async signMessage(message, context) { /* ... */ },
  async signAndSubmitTransaction(txJson, context) { /* ... */ },
  async recoverSession() { /* ... */ },
  isAvailable() { /* ... */ },
};

Metadata fields

Field	Type	Required	Description
id	string	✅	Unique kebab-case ID: "my-wallet"
name	string	✅	Human-readable name shown in the modal
icon	string	✅	URL or data URI for the wallet's logo (min 64×64 px)
type	"extension" | "mobile" | "hardware" | "web"	—	Hint for the modal UI
downloadUrl	string	—	Link shown when isAvailable() returns false
apiVersion	string	—	Set to WALLET_ADAPTER_API_VERSION from core

Required methods

connect(context): Promise<ConnectResult>

Opens the wallet, prompts the user to choose an account, and returns the session.

import type { ConnectContext, ConnectResult } from "@xrpl-wallet-kit/core";
import { WalletKitError, WalletKitErrorCode } from "@xrpl-wallet-kit/core";

async connect(context?: ConnectContext): Promise<ConnectResult> {
  if (!window.MyWallet) {
    throw new WalletKitError(
      WalletKitErrorCode.WALLET_NOT_FOUND,
      "My Wallet extension is not installed."
    );
  }

  const response = await window.MyWallet.connect();

  if (!response || !response.address) {
    throw new WalletKitError(
      WalletKitErrorCode.CONNECT_REJECTED,
      "User rejected the connection."
    );
  }

  return {
    account: {
      address: response.address,
      publicKey: response.publicKey,  // include if available
    },
    adapterId: this.id,
    connectedAt: Date.now(),
  };
}

disconnect(): Promise<void>

Cleans up the wallet connection. Must not throw if already disconnected.

async disconnect(): Promise<void> {
  try {
    await window.MyWallet?.disconnect();
  } catch {
    // ignore — already disconnected
  }
}

signTransaction(txJson, context): Promise<SignTransactionResult>

Asks the user to sign a prepared transaction. Returns the signed blob.

import type { SignTransactionResult } from "@xrpl-wallet-kit/core";

async signTransaction(
  txJson: Record<string, unknown>,
  context?: SignContext
): Promise<SignTransactionResult> {
  const result = await window.MyWallet.signTransaction({ transaction: txJson });

  if (!result || result.cancelled) {
    throw new WalletKitError(WalletKitErrorCode.SIGN_REJECTED, "User cancelled signing.");
  }

  return {
    signedTxBlob: result.blob,
    // hash: result.hash,  // if the wallet returns it
  };
}

Optional methods

signMessage(message, context): Promise<SignMessageResult>

Signs an arbitrary text message. Required if you want to use @xrpl-wallet-kit/auth.

import type { SignMessageResult } from "@xrpl-wallet-kit/core";

async signMessage(
  message: string,
  context?: SignContext
): Promise<SignMessageResult> {
  const result = await window.MyWallet.signMessage({ message });

  return {
    signature: result.signature,         // hex compact signature
    publicKey: result.publicKey,          // hex public key (optional)
    signatureKind: "signature",           // "signature" | "signedTx"
  };
}

signatureKind

Use "signature" if the wallet returns a raw compact ECDSA/EdDSA signature.
Use "signedTx" if the wallet returns a full signed transaction blob.
The auth verifier branches automatically based on signatureKind.

recoverSession(): Promise<WalletSession | null>

Attempts to restore a previous session without user interaction. Called on page load.

async recoverSession(): Promise<WalletSession | null> {
  try {
    const session = await window.MyWallet.getConnectedSession();
    if (!session?.address) return null;

    return {
      account: { address: session.address },
      adapterId: this.id,
      connectedAt: session.connectedAt ?? Date.now(),
    };
  } catch {
    return null;
  }
}

isAvailable(): boolean

Returns true if the wallet is detectable in the current browser.

isAvailable(): boolean {
  return typeof window !== "undefined" && !!window.MyWallet;
}

Factory function pattern

Wrap your adapter in a factory so callers can pass options:

import type { WalletAdapter } from "@xrpl-wallet-kit/core";
import { WALLET_ADAPTER_API_VERSION } from "@xrpl-wallet-kit/core";

export interface MyWalletAdapterOptions {
  clientId?: string;
  network?: "mainnet" | "testnet";
}

export function createMyWalletAdapter(options: MyWalletAdapterOptions = {}): WalletAdapter {
  return {
    id: "my-wallet",
    name: "My Wallet",
    icon: "https://my-wallet.io/logo.png",
    type: "extension",
    apiVersion: WALLET_ADAPTER_API_VERSION,
    downloadUrl: "https://chrome.google.com/webstore/detail/my-wallet",

    async connect(context) {
      // use options.clientId etc.
    },

    async disconnect() { /* ... */ },

    async signTransaction(txJson) { /* ... */ },

    isAvailable() {
      return typeof window !== "undefined" && !!window.MyWallet;
    },
  };
}

Error handling

Use WalletKitError with the correct code so the manager and UI can handle errors consistently:

Code	When to use
WALLET_NOT_FOUND	Extension/app not installed or not detected
CONNECT_REJECTED	User cancelled the connect prompt
SIGN_REJECTED	User cancelled or rejected signing
TIMEOUT	Wallet didn't respond within a reasonable time
NETWORK_ERROR	Network or node connection failure
UNKNOWN	Unexpected error not covered above

import { WalletKitError, WalletKitErrorCode } from "@xrpl-wallet-kit/core";

throw new WalletKitError(
  WalletKitErrorCode.SIGN_REJECTED,
  "User cancelled the sign request."
);

Register the adapter

Pass an instance to WalletManager:

import { WalletManager } from "@xrpl-wallet-kit/core";
import { createMyWalletAdapter } from "./my-wallet-adapter";

const manager = new WalletManager({
  adapters: [
    createMyWalletAdapter({ clientId: "..." }),
    // ...other adapters
  ],
  network: { /* ... */ },
});

Hard rules

Never include these in an adapter:

• No private keys, seeds, or secrets — adapters must never generate or store key material.
• No business logic — signAuthPayload, setPrimary, domain lookup, identity verification, etc. belong in the app layer, not the adapter.
• No DOM modals or framework code — adapters must be pure TypeScript with no UI dependencies.
• No hardcoded WalletConnect projectId — always require caller injection for credentials.

Building with AI

Adapter developer skill — a key differentiator

XRPL Wallet Kit ships a dedicated adapter developer skill for Claude Code and Codex. No other XRPL wallet library has an equivalent. The skill encodes the full adapter contract, capability rules, error codes, session restore safety rules, and cleanup requirements — so AI agents produce correct adapters from wallet documentation alone, without missing edge cases.

→ Full guide: Building Adapters with AI

Activate the skill at the start of your Claude Code session:

/xrpl-wallet-kit-adapter-developer

Then describe the wallet's API to the agent. It will scaffold the factory function, set capability flags correctly, map errors to WalletKitErrorCode, implement recoverSession() with passive-only rules, and generate a test scaffold — all following the adapter contract automatically.