Transactions overview#
A transaction on the Concordium blockchain is an operation which applies some change to the chain. All transactions are recorded on the chain and once recorded, they are immutable. A transaction always has one sender account and is signed using the keys of this account.
The most basic transaction is the CCD transfer that is used to send CCD from one account to another. However, there are several transaction types on the Concordium blockchain.
You can make transactions using either the Desktop Wallet, the Concordium Wallet for Mobile, Concordium Legacy Wallet, Concordium Wallet for Web, or the Concordium Client. Note that the Concordium Legacy Wallet, Concordium Wallet for Mobile, and Concordium Wallet for Web don’t support all transaction types, and that you need a LEDGER device to submit transactions from the Desktop Wallet.
Concordium Legacy Wallet |
Concordium Wallet for Mobile |
Concordium Wallet for Web |
Desktop Wallet |
Concordium Client |
|
|---|---|---|---|---|---|
Send CCD |
✓ |
✓ |
✓ |
✓ |
✓ |
Send CCD with a schedule |
✓ |
✓ |
|||
Shield CCD |
✓ |
✓ |
✓ |
✓ |
|
Unshield CCD |
✓ |
✓ |
✓ |
✓ |
|
Make shielded transfer |
✓ |
✓ |
✓ |
✓ |
|
Add validator |
✓ |
✓ |
✓ |
✓ |
✓ |
Remove validator |
✓ |
✓ |
✓ |
✓ |
✓ |
Update validator stake |
✓ |
✓ |
✓ |
✓ |
✓ |
Update restake earnings |
✓ |
✓ |
✓ |
✓ |
✓ |
Update validator keys |
✓ |
✓ |
✓ |
✓ |
✓ |
Update account credentials |
✓ |
✓ |
✓ |
||
Connect to dApps |
✓ |
✓ |
|||
Delegation |
✓ |
✓ |
✓ |
✓ |
✓ |
Smart contract transactions |
✓ |
Concordium Wallet for Web: supports send CCD, receive CCD, connect to dApps, validator management, delegation.
Concordium Wallet for Mobile: supports send CCD, receive CCD, shield CCD and unshield CCD, validator management, delegation, connect to dApps, add and manage tokens.
Concordium Legacy Wallet: supports send CCD, receive CCD, shield CCD and unshield CCD, validator management, delegation
Desktop Wallet: supports all transaction types (except smart contract transactions).
Concordium Client: supports all transaction types.
How transactions work#
When a validator receives a transaction from a participant on the chain, it performs a few basic checks to verify that the transaction is eligible for inclusion in a block. Transactions that meet all checks are considered successful and their changes are applied to the chain. If any of the checks fail, the transaction is ignored.
In some situations, transactions are included in the blockchain but recorded as rejected. This can happen, for example, if a sender tries to overdraw their account. If a transaction is rejected, the transaction fee is still deducted from the sender account but other than that, it has no effect.
There’s a sequence number associated with each account. This number increases sequentially with each transaction sent from the account and is recorded into the transaction. If a transaction has a sequence number that doesn’t match the current sequence number of the account, the transaction is not eligible for inclusion on the chain. This ensures that transactions are included only once and in a specific order.
Transaction fees#
Every transaction has a well-defined fee, and the fee of each transaction depends on the transaction type. When the transaction is submitted to the chain, the fee is deducted from the sender’s account and paid to the Concordium network as a fee for carrying out the transaction. The fee is measured in the unit NRG which corresponds to CCD according to a variable conversion factor (currently 1 NRG = 0.0001 CCD). The cost of transaction fees is stable in Euros, and therefore the price in CCD varies depending on the CCD to EUR exchange rate. Read more about conversions between CCD, NRG, and Euros in Exchange rates.
The fee will always be deducted from the Balance of the account, so it is important to have some available CCDs to cover fees.
You can see the fee in the transaction log.
Tools#
The Desktop Wallet#
The Desktop Wallet is a digital wallet that enables you to create and manage your Concordium identities, credentials, and accounts from your desktop and to create transactions such as sending CCD, adding a validator, and exporting and importing account information.
The Concordium Wallet for Mobile#
The Concordium Wallet for Mobile is a second generation digital smartphone wallet that enables you to create and manage your Concordium identities and accounts, to create simple and shielded transactions, validate and delegate, add and manage tokens, connect to dApps, and to export and import your accounts and identities.
The Concordium Wallet for Web#
The Concordium Wallet for Web is a web wallet extension that enables you to create and manage your Concordium identities and accounts, to create simple transactions, validate and delegate, and to connect to dApps.
The Concordium Legacy Wallet#
The Concordium Legacy Wallet is a digital smartphone wallet that enables you to create and manage your Concordium identities and accounts, to create simple and shielded transactions, validate and delegate, and to export and import your accounts and identities. If you are a validator who runs a staking pool, it is not possible for pool owners to set the commissions in the Concordium Legacy Wallet; they are fixed at 10%. If you want to be able to adjust commissions, you must use the Concordium Wallet for Mobile or Concordium Wallet for Web. For information about the process, see the delegation FAQ.
Command-line tool#
The Concordium distribution ships with a command-line tool named concordium-client. It is designed as a low-level interface to the Concordium blockchain. It cannot be used to create identities, but it can import accounts exported from the other wallets. Once an account has been imported, the tool can be used to do CCD transfers from the account, as well as send all other transaction types supported by the Concordium blockchain.
To learn more about the differences between the wallets, see Deciding between the wallets.
Warning
It is not possible to exchange identities and accounts between the Concordium Legacy Wallet and the Desktop Wallet. If you try to import a file that has been exported from the Concordium Legacy Wallet into the Desktop Wallet, the import will fail, and likewise, if you try to import a file exported from the Desktop Wallet into the Concordium Legacy Wallet.
Warning
Because of the difference in the way private keys are handled between Concordium Wallet for Mobile / Concordium Wallet for Web and the first generation wallets (Concordium Legacy Wallet and Desktop Wallet), you cannot exchange identities and accounts between them.
It is possible to exchange accounts and identities between the Concordium Wallet for Mobile and the Concordium Wallet for Web.
