# Smart contract fee introduction
In GXChain, deploying contracts, renewing contracts, and invoking contracts will result in different amounts of fees. This document describes the fees associated with smart contracts.
# The fee of deploying contract
The fee of deploying contract is paid by the caller, and is calculated as follows:
// base_fee is 0.01GXC, contract_size is the contract size, price_per_kbyte is the cost of 1kb ram, currently 0.2GXC
fee = base_fee + contract_size / 1024 * price_per_kbyte
# The fee of updating contract
The fee of updating contract is paid by the caller, and is calculated as follows:
// base_fee is 0.01GXC, contract_size is the contract size, price_per_kbyte is the cost of 1kb ram, currently 0.2GXC
fee = base_fee + new_contract_size / 1024 * price_per_kbyte
# The fee of calling contract
The calling contract is free, but there is a handling fee when calling. The handling fee consists of three parts, ram_fee, cpu_fee and base_fee, which will be returned later.
- ram_fee
Generated when an object is created or modified in the contract's table, ram_fee can be set to specify the associated account to pay. How ram_fee is calculated:
// ram_bytes is the number of bytes of memory occupied, price_per_kbyte_ram is the cost of 1kb ram, currently 0.2GXC
ram_fee = ram_bytes / 1024 * price_per_kbyte_ram
| ram_fee payer | Description |
|---|---|
| 0 | Contract account itself (same as _slef) |
| _self | Contract account itself (same as 0） |
| sender | Contract call account |
| original | The original calling account of the contract, which is the initial calling account in the cross-contract call |
Return of ram_fee: After deleting the object in the table, the fee charged at the time of creation will be returned to the payer to which the memory belongs.
- cpu_fee
now cpu_fee unit price is 0
- base_fee
In addition to using cpu_fee and ram_fee, the base contract fee is 0.001GXC.
Return of base_fee: The basic handling fee generated by calling the contract will be returned to the user's to-freeze balance, which needs to be collected manually by the user.
The calculation method for calling the smart contract fee is:
// base_fee is 0.001GXC, ram_fee is calculated according to the payer and occupied memory, cpu_fee is 0
fee = base_fee + ram_fee + cpu_fee