Otsu Wallet Adapter

Otsu Wallet is an MV3 browser extension wallet for XRPL. It supports mainnet, testnet, and devnet, and offers granular dApp permission scopes, transaction simulation, and risk scanning before user approval.

Installation

npm install @xrpl-wallet-kit/adapter-otsu

Quick Start

import { createOtsuAdapter } from "@xrpl-wallet-kit/adapter-otsu";

const adapter = createOtsuAdapter();

Options

Option	Type	Default	Description
provider	OtsuProvider	window.xrpl (with isOtsu: true)	Override the injected provider (useful for testing)
scopes	string[]	["read", "sign", "submit", "switchNetwork"]	Permission scopes to request at connect time

Scope declaration is required upfront

Otsu requires all needed scopes to be declared at connection time. It does not support incremental scope elevation. Declare the minimum set your dApp needs: if you only need to read the address, use scopes: ["read"].

Connection Flow

1. User clicks Otsu Wallet in the connect modal
2. Otsu extension opens a notification popup for the user to approve the requested scopes
3. On approval, the adapter returns the XRPL address and resolves the active network type
4. The adapter queries provider.getNetwork() to populate networkType (MAINNET / TESTNET / DEVNET)

Provider Detection

The adapter looks for window.xrpl with isOtsu === true. This discriminator prevents collision with xrpl.js or other wallets injecting at window.xrpl.

Capabilities

Capability	Supported
connect	✅
disconnect	✅
signMessage	✅
signTransaction	✅
signAndSubmit	✅
sessionRestore	✅
payments	⚠️ pending live testing
nftOffers	⚠️ pending live testing

Message Signing

Otsu returns a compact message signature (ECDSA/Ed25519):

const result = await manager.signMessage({ message: "Verify wallet ownership" });

// result.signatureKind === "signature"
// result.proof      — same as result.signature
// result.signature  — compact hex signature
// result.publicKey  — account public key (when Otsu exposes it)

Transactions

Otsu supports both sign-only and sign-and-submit flows:

// Sign-only (no broadcast)
const signed = await manager.signTransaction({
  txJson: {
    TransactionType: "Payment",
    Account: session.account.address,
    Destination: "rPT1Sjq2YGrBMTttX4GZHjKu9dyfzbpAYe",
    Amount: "1000000",
  },
});
// signed.txBlob — hex blob (also exposed as signed.tx_blob for compatibility)
// signed.hash   — pre-submission hash

// Sign + submit
const result = await manager.signAndSubmit({
  txJson: { TransactionType: "Payment", ... },
});
// result.hash   — transaction hash after submission
// result.status — e.g. "tesSUCCESS"

When signAndSubmit is called with { submit: false }, the adapter automatically falls back to signTransaction — the blob is returned without broadcasting.

Session Restore / Mobile Return Recovery

Session restore: on page reload, the adapter checks provider.isConnected(). If connected, it calls provider.getAddress() to verify the address matches the stored session, then silently restores.

There is no mobile return / deeplink recovery — Otsu is a desktop browser extension.

Known Limitations

• payments and nftOffers capabilities are not yet confirmed with live Otsu transaction tests. Enable them in your adapter options once Payment and NFT offer payloads have been validated end-to-end.
• Scopes must be declared at connect time — no incremental scope elevation after the initial connection.
• The Otsu Wallet is an early-stage project. The provider API may change in future releases.

Troubleshooting

Extension not detected? Verify Otsu Wallet is installed and that window.xrpl.isOtsu === true. In DevTools: console.log(window.xrpl?.isOtsu). If this returns undefined, the extension is not installed or did not inject.

Another wallet also uses window.xrpl? Otsu is identified by window.xrpl.isOtsu === true. Other wallets at window.xrpl without that flag are ignored. Inject the Otsu provider directly via options.provider if needed.

Scope permission denied? If the user denies a scope at connection time, the adapter throws a CONNECTION_REJECTED error. Request only the minimum scopes needed (["read"] for address-only flows).

signAndSubmit failed? Ensure the sign and submit scopes were approved at connect time. Without those scopes, Otsu will reject signing requests.

Monorepo Integration Notes

This adapter is an official monorepo package at packages/adapters/otsu/. The placeholder icon in the source should be replaced with the official Otsu Wallet logo before publishing. Obtain the logo from the assets/ folder of the otsu-wallet GitHub repository and convert it to a data:image/...;base64 URL.

Manual Test Checklist

• [ ] Extension detected — window.xrpl.isOtsu === true
• [ ] Connect with default scopes — Otsu popup shows all 4 scopes, address returned
• [ ] Connect with scopes: ["read"] — Otsu popup shows read-only scope
• [ ] signAndSubmit — Otsu popup shows txn with simulation/risk info, hash returned
• [ ] signTransaction — Otsu popup shows txn, txBlob returned without broadcast
• [ ] signMessage — Otsu popup shows message, compact signature returned, signatureKind: "signature"
• [ ] Page reload — autoReconnect() restores session via isConnected() + address match
• [ ] Disconnect — provider.disconnect() called, session cleared
• [ ] Extension not installed — modal shows install link to GitHub
• [ ] Scope denied — user unchecks scopes, adapter throws CONNECTION_REJECTED
• [ ] Rejection — user cancels popup, adapter throws readable error