# Transaction types

You can interact with the WoopChain JSON-RPC API using different transaction types (specified by the `transactionType` parameter).

The following API objects use a unique format for each `transactionType`:

* [Pending transaction object](https://github.com/Woop-Chain/docs/blob/main/docs/woop/reference/api/objects.md#pending-transaction-object)
* [Transaction object](https://github.com/Woop-Chain/docs/blob/main/docs/woop/reference/api/objects.md#transaction-object)
* [Transaction call object](https://github.com/Woop-Chain/docs/blob/main/docs/woop/reference/api/objects.md#transaction-call-object)
* [Transaction receipt object](https://github.com/Woop-Chain/docs/blob/main/docs/woop/reference/api/objects.md#transaction-receipt-object)

## `FRONTIER` transactions

Transactions with type `FRONTIER` are *legacy transactions* that use the transaction format existing before typed transactions were introduced in [EIP-2718](https://eips.ethereum.org/EIPS/eip-2718). They contain the parameters `chainId`, `nonce`, `gasPrice`, `gasLimit`, `to`, `value`, `data`, `v`, `r`, and `s`. Legacy transactions don't use [access lists](#access_list-transactions) or incorporate [EIP-1559 fee market changes](#eip1559-transactions).

## `ACCESS_LIST` transactions

Transactions with type `ACCESS_LIST` are transactions introduced in [EIP-2930](https://eips.ethereum.org/EIPS/eip-2930). They contain, along with the [legacy parameters](#frontier-transactions), an `accessList` parameter, which specifies an array of addresses and storage keys that the transaction plans to access (an *access list*). `ACCESS_LIST` transactions must specify an access list, and they don't incorporate [EIP-1559 fee market changes](#eip1559-transactions).

## `EIP1559` transactions

Transactions with type `EIP1559` are transactions introduced in [EIP-1559](https://github.com/ethereum/EIPs/blob/master/EIPS/eip-1559.md). EIP-1559 addresses the network congestion and overpricing of transaction fees caused by the historical fee market, in which users send transactions specifying a gas price bid using the `gasPrice` parameter, and miners choose transactions with the highest bids.

`EIP1559` transactions don't specify `gasPrice`, and instead use an in-protocol, dynamically changing *base fee* per gas. At each block, the base fee per gas is adjusted to address network congestion as measured by a gas target.

`EIP1559` transactions contain, along with the [`accessList`](#access_list-transactions) parameter and [legacy parameters](#frontier-transactions) except for `gasPrice`, a `maxPriorityFeePerGas` parameter, which specifies the maximum fee the sender is willing to pay per gas above the base fee (the maximum *priority fee* per gas), and a `maxFeePerGas` parameter, which specifies the maximum total fee (base fee + priority fee) the sender is willing to pay per gas.

An `EIP1559` transaction always pays the base fee of the block it's included in, and it pays a priority fee as priced by `maxPriorityFeePerGas` or, if the base fee per gas + `maxPriorityFeePerGas` exceeds `maxFeePerGas`, it pays a priority fee as priced by `maxFeePerGas` minus the base fee per gas. The base fee is burned, and the priority fee is paid to the miner that included the transaction. A transaction's priority fee per gas incentivizes miners to include the transaction over other transactions with lower priority fees per gas.

`EIP1559` transactions must specify both `maxPriorityFeePerGas` and `maxFeePerGas`. They must not specify `gasPrice`.