What is the process to dispute or reverse an on-chain transaction (if any)?

I once sent ETH to the wrong address; there was no automatic reversal. I asked the recipient to send it back.

Short version: you can't dispute or reverse an on-chain tx once it's confirmed. No central authority. If you sent to the wrong address, your best bet is contacting the recipient to return it or using any contract/escrow you set up. Before confirmation, you can use RBF (Bitcoin) to speed up or replace, but not reverse. If funds were in an exchange, ask them for a reversal.

In most blockchains, you can't reverse an on-chain transaction after it confirms. Here's a practical path you can take. First, check whether the transaction is still unconfirmed; if so, you can try to replace it or cancel it with your wallet's 'speed up' or 'cancel' feature, depending on the chain. For Bitcoin, this is RBF; for Ethereum, you can send another tx with the same nonce and higher gas to replace. If it's already mined, reversal isn’t automatic, reach out to the recipient and ask for a refund or use any included escrow/refund mechanism if you used one. If funds were sent to an exchange, contact the exchange immediately; they may be able to reverse if the funds are still in a controlled hot wallet. For scams or compliance issues, report to your wallet provider.

Technically and practically, on-chain transactions are designed to be final. There is no universal dispute channel like a chargeback, and reversals depend on pre-programmed safeguards or recipient cooperation rather than a central authority. Pre-confirmation, you have a few options: speed up by raising gas, replace-by-fee where supported (Bitcoin), or cancel via wallet controls. Post-confirmation, a reversal only happens if a contract or protocol explicitly refunds, or if the recipient agrees to return funds. In custodial contexts (exchanges, hot wallets), you may have some recovery options by engaging support, freezing assets, or coordinating a manual reversal, but it’s not guaranteed and depends on policy and legal constraints. If you’ve been tricked by a scam or made an error, your best path is to document the transaction, report it, and see if the counterparty cooperates. My practice: always verify the address on a separate device, test with small amounts, and use multisig or an escrow contract for high-value transfers to preserve a dispute mechanism.