# ContractMatching

### type ContractBuilder

```go
type ContractBuilder struct {
    AccountId    AccountId
    SubAccountId SubAccountId
    SlotId       SlotId
    Nonce        Nonce
    PairId       PairId
    Size         BigUint
    Price        BigUint
    Direction    bool
    TakerFeeRate uint8
    MakerFeeRate uint8
    HasSubsidy   bool
}
```

Builder used to build [Contract](#type-contract)

### type Contract

The [Contract](/developer/api-and-sdk/transaction/contract_matching.md) struct of taker and maker in perpetual contract, it's a opaque data type.

#### func NewContract

```go
func NewContract(builder ContractBuilder) *Contract
```

Create a new Contract.

#### func (\*Contract) IsLong

```go
func (*Contract) IsLong() bool
```

Return true if the contract opens a long position.

#### func (\*Contract) IsShort

```go
func (*Contract) IsShort() bool
```

Return true if the contract opens a short position.

#### func (\*Contract) GetSignature

```go
func (_self *Contract) GetSignature() ZkLinkSignature
```

Get the L3 signature of the contract.

#### func (\*Contract) IsSignatureValid

```go
func (*Contract) IsSignatureValid() bool
```

Check if the signature is valid or not.

#### func (\*Contract) GetBytes

```golang
func (*Contract) GetBytes() []uint8 
```

Get the encoded bytes that used to create the L3 signature.

#### func (\*Contract) CreateSignedContract

```go
func (*Contract) CreateSignedContract(zklinkSigner *ZkLinkSigner) (*Contract, error)
```

Create a new contract with L3 signature.

**input:**

* zklinkSigner: [zklinkSigner](/developer/sdk/changelog/signer.md#type-zklinksigner)

### type ContractMatchingBuilder

```go
type ContractMatchingBuilder struct {
    AccountId    AccountId
    SubAccountId SubAccountId
    Taker        *Contract
    Maker        []*Contract
    Fee          BigUint
    FeeToken     TokenId
}
```

### type ContractMatching

The [ContractMatching](/developer/api-and-sdk/transaction/contract_matching.md) transaction in perpetual contract, it's a opaque data type.

#### NewContractMatching(builder ContractMatchingBuilder)

```go
func NewContractMatching(builder ContractMatchingBuilder) *ContractMatching
```

Create a new ContractMatching transaction.

#### func (\*ContractMatching) GetBytes

```go
func (_self *ContractMatching) GetBytes() []uint8
```

Get the encoded bytes that used to create the L3 signature. See more in [Private Key and Signature](/developer/api-and-sdk/private_key/contract_matching.md).

#### func (\*ContractMatching) TxHash

```go
func (*ContractMatching) TxHash() []uint8
```

Get the transaction hash of the transaction.

#### func (\*ContractMatching) JsonStr

```go
func (*ContractMatching) JsonStr() string
```

Get the json string of the the transaction.

#### func (\*ContractMatching) IsValid

```go
func (*ContractMatching) IsValid() bool
```

Check if the transaction is valid or not.

#### func (\*ContractMatching) CreateSignedTx

```go
func (*ContractMatching) CreateSignedTx(signer *ZkLinkSigner) (*ContractMatching, error)
```

Create a new transaction with L3 signature.

**input:**

* signer: [ZkLinkSigner](/developer/sdk/changelog/signer.md#type-zklinksigner)

#### func (\*ContractMatching) GetSignature

```go
func (*ContractMatching) GetSignature() ZkLinkSignature
```

Get the L3 signature of the transaction.

#### func (\*ContractMatching) IsSignatureValid

```go
func (*ContractMatching) IsSignatureValid() bool
```

Check if the inside L3 signature is valid or not.

#### func (\*ContractMatching) ToZklinkTx

```go
func (*ContractMatching) ToZklinkTx() ZkLinkTx
```

Change the transaction to the [ZkLinkTx](/developer/sdk/changelog/basic_types.md#zklinktx)


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