Memoless Transactions - THORChain Without Wallet Limitations

Memoless transactions are a long-awaited upgrade to THORChain that let users pre register their intent before transacting. What may sound complex is actually straightforward: it allows users to use any wallet without connecting them to operate their trasnactions.

Let's dive in ⬇️

🎓 What Is a Memo and Why Was it Needed?

On THORChain, every action requires an inbound transaction with a memo.
The memo tells the network what you want to do, such as swapping BTC to ETH, adding or removing liquidity, or bonding RUNE.

But memos come with limitations. Not all wallets support them, some chains restrict memo size, and others do not support memos at all. This creates friction for users and makes THORChain integrations more difficult.

👉 With memoless transactions, users register their intent before sending funds rather than embedding it inside the transaction itself.

This removes reliance on wallet features and makes THORChain usable with almost any self-custody wallet.

⚙️ How Memoless Transactions Work

Before sending funds, a user (or the interface they are using) creates a pre registration on THORChain. This stores the action they want to perform and the asset they plan to deposit

THORChain then generates a five-digit Reference ID, for example 12345.
This ID is the link between the incoming transaction and the stored intent.

The Reference ID can be used in two ways:

• The first is straightforward. Instead of using the classical long memo that may exceed a chain’s limits, the user can include the short Reference ID instead. This is especially helpful on chains and wallets with strict size restrictions, such as Bitcoin’s 80-byte OP_RETURN.
• The second method is what transforms the experience. Instead of attaching any memo at all, the user can encode the Reference ID in the amount of the transaction they send. For example, sending exactly 9.99912345 BTC embeds the digits “12345” at the end of the amount. When THORChain receives this deposit, the network reads the last five digits and correlates them with the pre registered memo. In this case, the user doesn't need to add a memo or modify their wallet settings in any way.

Why This Matters for Everyday Users

Memoless transactions solve a major challenge for cross chain users. Not every wallet supports THORChain, and many wallets do not support memos at all. By allowing users to pre register intent separately and encode the Reference ID in the send amount, memoless deposits remove this dependency entirely.

👉 A user can now perform a THORChain swap from any wallet they choose, even if that wallet has no built in THORChain support.

This greatly improves accessibility. When an interface generates a Reference ID (the intent) for a user, it also provides a QR code that contains the THORChain inbound address and the exact amount to send.

👉 The user scans the QR Code, sends the funds and THORChain handles the rest.

The process requires no wallet connection and no special features. Any asset from any self custody wallet can now be part of a THORChain swap so long as the amount is encoded correctly.

Why This Is Especially Helpful and More Secure for Bitcoin Holders

Bitcoin users value security, self-custody, and simple transaction flows. Memoless transactions align with this by removing the need to connect a Bitcoin wallet to any THORChain frontend. Wallet connections are one of the most common points of compromise in crypto, since a malicious or spoofed interface can present fake signatures or misleading approvals.

👉 With memoless deposits, THORChain never asks the user to connect their wallet at all. You simply send Bitcoin the same way you always do, directly from your wallet to a THORChain vault.

Because the process only requires sending an exact amount, it works naturally with hardware wallets, multisig setups, and cold storage. The Bitcoin transaction itself remains completely standard. There is no memo, no metadata, and nothing that changes how the transaction appears on chain. This preserves privacy and maintains the clean, minimal structure Bitcoin users expect.

For Bitcoin holders who want cross chain liquidity without exposing their wallet to a frontend connection, memoless transactions provide a straightforward and more secure way to use THORChain.

👉Users stay fully self custodial and never need to rely on wrapped assets or centralised swap services.

Practical Limitations to Be Aware Of

Although memoless transactions simplify many interactions, they do come with a few constraints:

1️⃣ The most important rule is precision. Users must send exactly the amount the interface specifies. The final digits of that amount are what THORChain uses to match the deposit with the correct Reference ID. A slight mismatch can break the correlation.

2️⃣ Each Reference ID currently has a maximum of one use. Once it has been consumed by an inbound transaction, a new one is required for additional actions.

3️⃣ There is also a six hour time to live. If a user sends a transaction with low gas or slow confirmation times and the Reference ID expires before it arrives, THORChain will not process it, so timing matters.

4️⃣ There are also asset related limitations. Only gas assets are supported at this stage. ERC20 tokens will become compatible after the rollout of RouterV6.

5️⃣ Users should also be aware of each chain’s decimal precision. Chains with more than eight decimals, like Ethereum, truncate anything beyond the eighth digit. Chains with fewer decimals, such as Cosmos Hub with six, require the Reference ID to fit within the available digits. In practice, most frontends handle this automatically.

Conclusion

Memoless transactions reshape the THORChain experience by making user intent registration simpler, more flexible, and available to anyone with a standard blockchain wallet.

The feature removes long standing barriers to Bitcoin integration and eliminates the need for memo compatible wallets, while keeping the process self custodial and straightforward.

For users who value simplicity and security, especially those operating on Bitcoin, this upgrade offers a clearer and more accessible way to interact with THORChain without altering how their native assets behave on their original chains.

For more information: https://blog.thorchain.org/new-features-on-thorchain-limit-orders-memoless-transactions/