[cryptocurrencies] Deal with a pending transaction

The problem is caused by a too-small fee for that transaction.

Bitcoin

• Way 1: Wait for over 48h (2–3 days) and that transaction will be rejected. :D
• Way 2: Re-broadcast your transaction to other nodes:

There some nodes here:

https://api.blockcypher.com/v1/btc/main/txs/push
https://blockchain.info/pushtx
https://api.blockchair.com/bitcoin/push/transaction
https://coinb.in/api/?uid=1&key=12345678901234567890123456789012&setmodule=bitcoin&request=sendrawtransaction
https://api.smartbit.com.au/v1/blockchain/pushtx/

Ethereum

Case 1: If you still have a balance > 0 on your wallet => Cancel it

https://info.etherscan.com/how-to-cancel-ethereum-pending-transactions/

Summary of the solution to solve case 1:

1. Create a new transaction send from yourself to yourself with amount = 0. =]]
2. Use the Average or High gas fee suggested by the wallet app
3. Change the transaction Nonce of the new transaction with the same value of the transaction which wants to cancel

Wallet support articles on speeding up/replacing/cancel transactions:

• MEW — Checking or Replacing a Transaction After it’s Been Sent
• ImToken — Why transaction pending？