SmartContract

scrypt-ts / SmartContract

Class: SmartContract

The main contract class. To write a contract, extend this class as such:

Example

class YourSmartContract extends SmartContract {
  // your smart contract code here
}

Constructors

constructor

Properties

Accessors

Other Methods

Signature Verification Methods

Constructors

constructor

• new SmartContract(...args)

Parameters

Name	Type
`...args`	`any`[]

Defined in

dist/smart-contract/contract.d.ts:149

Properties

call

• Private call: any

Defined in

dist/smart-contract/contract.d.ts:422

dummySignSingleCallTx

• Private dummySignSingleCallTx: any

Defined in

dist/smart-contract/contract.d.ts:426

from

• Optional from: IUnspentOutput | TxOutputRef

from is a reference to a transaction output where the props of this contract instance are located/stored on chain. In other words, it's the start point for the lifecycle of this instance.

Defined in

dist/smart-contract/contract.d.ts:100

hasPrevouts

• Private hasPrevouts: any

Defined in

dist/smart-contract/contract.d.ts:317

multiContractCall

• Private multiContractCall: any

Defined in

dist/smart-contract/contract.d.ts:424

signSingleCallTx

• Private signSingleCallTx: any

Defined in

dist/smart-contract/contract.d.ts:425

singleContractCall

• Private singleContractCall: any

Defined in

dist/smart-contract/contract.d.ts:423

to

• Optional to: TxInputRef

to is a reference to a transaction input where a public method of this contract instance is called. In other words, it's the end point for the lifecycle of this instance.

Defined in

dist/smart-contract/contract.d.ts:105

Accessors

asmArgs

• get asmArgs(): AsmVarValues

Returns set ASM variable values.

Returns

AsmVarValues

Defined in

dist/smart-contract/contract.d.ts:201

balance

• get balance(): number

Get the current locked balance of the contract

Returns

number

Defined in

dist/smart-contract/contract.d.ts:471

changeAddress

• get changeAddress(): Ripemd160

Get the change address of the change output for to.tx.

Onchain

Returns

Ripemd160

the change address of to.tx

Defined in

dist/smart-contract/contract.d.ts:304

changeAmount

• get changeAmount(): bigint

Get the amount of the change output for to.tx.

Onchain

Returns

bigint

amount in satoshis

Defined in

dist/smart-contract/contract.d.ts:292

codePart

• get codePart(): string

Returns code part of the lockingScript, in hex format.

Returns

string

Defined in

dist/smart-contract/contract.d.ts:186

ctx

• get ctx(): ScriptContext

You can directly access the context through this.ctx in any public @method. [ScriptContext][https://docs.scrypt.io/how-to-write-a-contract/scriptcontext](https://docs.scrypt.io/how-to-write-a-contract/scriptcontext) can be considered additional information a public method gets when called, besides its function parameters.

Onchain

Returns

ScriptContext

Defined in

dist/smart-contract/contract.d.ts:481

dataPart

• get dataPart(): Script

Returns

Script

Defined in

dist/smart-contract/contract.d.ts:354

debug

• get debug(): DebugFunctions

A set of functions for debugging contracts, which can only be called in @method methods.

Returns

DebugFunctions

Defined in

dist/smart-contract/contract.d.ts:467

lockingScript

• get lockingScript(): Script

Returns a lockingScript of contract.

Returns

Script

Defined in

dist/smart-contract/contract.d.ts:178

methods

• get methods(): Record<string, (...args: any) => Promise<ContractTransaction>>

An object to access all public @methods

Returns

Record<string, (...args: any) => Promise<ContractTransaction>>

Defined in

dist/smart-contract/contract.d.ts:430

prevouts

• get prevouts(): ByteString

Get the prevouts for to.tx.

Onchain

Returns

ByteString

prevouts in satoshis

Defined in

dist/smart-contract/contract.d.ts:298

provider

• get provider(): Provider

Get the connected [provider][https://docs.scrypt.io/how-to-test-a-contract#provider](https://docs.scrypt.io/how-to-test-a-contract#provider)

Returns

Provider

Defined in

dist/smart-contract/contract.d.ts:379

scriptHash

• get scriptHash(): string

Returns sha256 hash of the current locking script, formatted as a LE hex string.

Returns

string

Defined in

dist/smart-contract/contract.d.ts:190

scriptSize

• get scriptSize(): number

Returns script size of lockingScript.

Returns

number

Defined in

dist/smart-contract/contract.d.ts:182

signer

• get signer(): Signer

Get the connected [signer][https://docs.scrypt.io/how-to-test-a-contract#signer](https://docs.scrypt.io/how-to-test-a-contract#signer)

Returns

Signer

Defined in

dist/smart-contract/contract.d.ts:375

utxo

• get utxo(): IUnspentOutput

Get the utxo where the contract is currently located

Returns

IUnspentOutput

Defined in

dist/smart-contract/contract.d.ts:475

Other Methods

bindTxBuilder

▸ bindTxBuilder(methodName, txBuilder): void

Bind a transation builder for a public @method

Parameters

Name	Type	Description
`methodName`	`string`	the public `@method` name
`txBuilder`	`MethodCallTxBuilder`<`SmartContract`>	a transation builder

Returns

void

Defined in

dist/smart-contract/contract.d.ts:438

buildChangeOutput

▸ buildChangeOutput(): ByteString

A built-in function to create an [change output][https://wiki.bitcoinsv.io/index.php/Change](https://wiki.bitcoinsv.io/index.php/Change).

Onchain

Returns

ByteString

Defined in

dist/smart-contract/contract.d.ts:233

buildContractInput

▸ buildContractInput(fromUTXO?): Input

Build an input that includes the contract

Parameters

Name	Type	Description
`fromUTXO?`	`IUnspentOutput`	A parameter to specify the `utxo` where the contract is located

Returns

Input

an input that includes the contract

Defined in

dist/smart-contract/contract.d.ts:448

buildDeployTransaction

▸ buildDeployTransaction(utxos, amount, changeAddress): Promise<Transaction>

creates a tx to deploy the contract. Users override it to cutomize a deployment tx as below.

Example

override async buildDeployTransaction(utxos: UTXO[], amount: number, changeAddress?: bsv.Address | string): Promise<bsv.Transaction> {
 const deployTx = new bsv.Transaction()
 // add p2pkh inputs for paying tx fees
 .from(utxos)
 // add contract output
 .addOutput(new bsv.Transaction.Output({
   script: this.lockingScript,
   satoshis: amount,
 }))
 // add the change output if passing `changeAddress`
 if (changeAddress) {
   deployTx.change(changeAddress);
   if (this._provider) {
     deployTx.feePerKb(await this.provider.getFeePerKb());
   }
 }

 return deployTx;
}

Parameters

Name	Type	Description
`utxos`	`IUnspentOutput`[]	represents one or more P2PKH inputs for paying transaction fees.
`amount`	`number`	the balance of contract output
`changeAddress`	`string` \| `Address`	a change address

Returns

Promise<Transaction>

Defined in

dist/smart-contract/contract.d.ts:409

buildStateOutput

▸ buildStateOutput(amount): ByteString

A built-in function to create an output containing the new state. It takes an input: the number of satoshis in the output.

Onchain

Parameters

Name	Type	Description
`amount`	`bigint`	the number of satoshis in the output

Returns

ByteString

an output containing the new state

Defined in

dist/smart-contract/contract.d.ts:227

checkPreimage

▸ checkPreimage(txPreimage): boolean

Using the [OP_PUSH_TX][https://medium.com/@xiaohuiliu/op-push-tx-3d3d279174c1](https://medium.com/@xiaohuiliu/op-push-tx-3d3d279174c1) technique, check if txPreimage is the preimage of the current transaction.

Onchain

Parameters

Name	Type	Description
`txPreimage`	`SigHashPreimage`	The format of the preimage is [specified][https://github.com/bitcoin-sv/bitcoin-sv/blob/master/doc/abc/replay-protected-sighash.md#digest-algorithm](https://github.com/bitcoin-sv/bitcoin-sv/blob/master/doc/abc/replay-protected-sighash.md#digest-algorithm)

Returns

boolean

true if txPreimage is the preimage of the current transaction. Otherwise false.

Defined in

dist/smart-contract/contract.d.ts:274

checkPreimageAdvanced

▸ checkPreimageAdvanced(txPreimage, privKey, pubKey, inverseK, r, rBigEndian, sigHashType): boolean

Same as checkPreimage, but support customized more settings.

Onchain

Parameters

Name	Type	Description
`txPreimage`	`SigHashPreimage`	The format of the preimage is [specified][https://github.com/bitcoin-sv/bitcoin-sv/blob/master/doc/abc/replay-protected-sighash.md#digest-algorithm](https://github.com/bitcoin-sv/bitcoin-sv/blob/master/doc/abc/replay-protected-sighash.md#digest-algorithm)
`privKey`	`PrivKey`	private Key
`pubKey`	`PubKey`	public key
`inverseK`	`bigint`	inverseK
`r`	`bigint`	r
`rBigEndian`	`string`	must be mininally encoded, to conform to strict DER rule https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki#der-encoding
`sigHashType`	`SigHashType`	A SIGHASH flag is used to indicate which part of the transaction is signed by the ECDSA signature.

Returns

boolean

true if txPreimage is the preimage of the current transaction. Otherwise false.

Defined in

dist/smart-contract/contract.d.ts:259

checkPreimageSigHashType

▸ checkPreimageSigHashType(txPreimage, sigHashType): boolean

Same as checkPreimage, but support customized sighash type

Onchain

Parameters

Name	Type	Description
`txPreimage`	`SigHashPreimage`	The format of the preimage is [specified][https://github.com/bitcoin-sv/bitcoin-sv/blob/master/doc/abc/replay-protected-sighash.md#digest-algorithm](https://github.com/bitcoin-sv/bitcoin-sv/blob/master/doc/abc/replay-protected-sighash.md#digest-algorithm)
`sigHashType`	`SigHashType`	A SIGHASH flag is used to indicate which part of the transaction is signed by the ECDSA signature.

Returns

boolean

true if txPreimage is the preimage of the current transaction. Otherwise false.

Defined in

dist/smart-contract/contract.d.ts:267

connect

▸ connect(providerOrSigner): Promise<void>

connect a provider or a signer.

Parameters

Name	Type	Description
`providerOrSigner`	`Provider` \| `Signer`	a provider or a signer

Returns

Promise<void>

Defined in

dist/smart-contract/contract.d.ts:371

deploy

▸ deploy(amount?, options?): Promise<TransactionResponse>

Deploy the contract

Parameters

Name	Type	Description
`amount?`	`number`	satoshis locked in the contract, 1 sat by default
`options?`	`Object`	An optional parameter that can specify the change address
`options.address?`	`Address`	-
`options.changeAddress?`	`Address`	-

Returns

Promise<TransactionResponse>

The transaction id of the successfully deployed contract

Defined in

dist/smart-contract/contract.d.ts:416

getStateScript

▸ getStateScript(): ByteString

A built-in function to create a locking script containing the new state.

Onchain

Returns

ByteString

a locking script that containing the new state

Defined in

dist/smart-contract/contract.d.ts:239

insertCodeSeparator

▸ insertCodeSeparator(): void

Insert and OP_CODESEPARATOR at this point of the functions logic. More detail about [OP_CODESEPARATOR][https://wiki.bitcoinsv.io/index.php/OP_CODESEPARATOR](https://wiki.bitcoinsv.io/index.php/OP_CODESEPARATOR)

Returns

void

Defined in

dist/smart-contract/contract.d.ts:279

isStateful

▸ isStateful(): boolean

Check if the contract is a stateful contract

Returns

boolean

true if contract has a @prop(true) property

Defined in

dist/smart-contract/contract.d.ts:453

markAsGenesis

▸ markAsGenesis(): SmartContract

Mark the contract as genesis contracts

Returns

SmartContract

Defined in

dist/smart-contract/contract.d.ts:220

▸ next(opt?): SmartContract

Parameters

Name	Type	Description
`opt?`	`Object`	properties that only references are copied, but not deep clone their values.
`opt.refCloneProps?`	`string`[]	-

Returns

SmartContract

a cloned contract instance with this.from = undefined and this.to = undefined

Defined in

dist/smart-contract/contract.d.ts:214

setAsmVars

▸ setAsmVars(asmVarValues): void

If the compiled contract contains any ASM variable templates (e.g. P2PKH.unlock.pubKeyHash), replace them with the passed values.

Parameters

Name	Type	Description
`asmVarValues`	`AsmVarValues`	type that contains the actual values.

Returns

void

Defined in

dist/smart-contract/contract.d.ts:197

setDataPartInASM

▸ setDataPartInASM(dataPart): void

set the data part of the contract in ASM format

Parameters

Name	Type
`dataPart`	`string`

Returns

void

Defined in

dist/smart-contract/contract.d.ts:348

setDataPartInHex

▸ setDataPartInHex(dataPart): void

set the data part of the contract in hex format

Parameters

Name	Type
`dataPart`	`string`

Returns

void

Defined in

dist/smart-contract/contract.d.ts:353

sigTypeOfMethod

▸ sigTypeOfMethod(methodName): number

Get [sigHash type][https://docs.scrypt.io/how-to-write-a-contract/scriptcontext#sighash-type](https://docs.scrypt.io/how-to-write-a-contract/scriptcontext#sighash-type) of the public @method function.

Parameters

Name	Type	Description
`methodName`	`string`	name of the public `@method` function.

Returns

number

a sigHash type

Defined in

dist/smart-contract/contract.d.ts:459

compile

▸ Static compile(): Promise<Artifact>

compiling the scrypt source which is the output of transpiling. Calling this function to output the contract artifact file. only used for testing. This function should not be called in production environment.

Returns

Promise<Artifact>

if compiling succeed, otherwise it throws error.

Defined in

dist/smart-contract/contract.d.ts:124

fromTx

▸ Static fromTx<T>(this, tx, atOutputIndex, offchainValues?): T

recover a SmartContract instance from the transaction if the contract contains onchain properties of type HashedMap or HashedSet it's required to pass all their offchain raw data at this transaction moment

Type parameters

Name	Type
`T`	extends `SmartContract`<`T`>

Parameters

Name	Type	Description
`this`	(...`args`: `any`[]) => `T`	-
`tx`	`Transaction`	transaction
`atOutputIndex`	`number`	output index of `tx`
`offchainValues?`	`Record`<`string`, `any`>	the value of offchain properties, the raw data of onchain `HashedMap` and `HashedSet` properties, at this transaction moment

Returns

T

Defined in

dist/smart-contract/contract.d.ts:499

getArtifact

▸ Static getArtifact(): Artifact

The contract class needs to call this function before instantiating.

Returns

Artifact

Defined in

dist/smart-contract/contract.d.ts:138

loadArtifact

▸ Static loadArtifact(artifactFile?): void

This function is usually called on the front-end. The contract class needs to call this function before instantiating.

Parameters

Name	Type	Description
`artifactFile?`	`string` \| `Artifact`	a merged contract artifact object, or its file path

Returns

void

Defined in

dist/smart-contract/contract.d.ts:132

multiContractCall

▸ Static multiContractCall(partialContractTx, signer, options?): Promise<MultiContractTransaction>

When the @methods of multiple contracts is called in a transaction, this function signs and broadcasts the final transaction.

Parameters

Name	Type	Description
`partialContractTx`	`ContractTransaction`	a `ContractTransation` with a unsigned transation.
`signer`	`Signer`	a signer to sign the transation.
`options?`	`MultiContractCallOptions`	-

Returns

Promise<MultiContractTransaction>

a MultiContractTransation with a signed transation.

Defined in

dist/smart-contract/contract.d.ts:510

parseCallData

▸ Static parseCallData(tx, inputIndex): CallData

parse call data when a contract public method called in a transation.

Parameters

Name	Type
`tx`	`Transaction`
`inputIndex`	`number`

Returns

CallData

Defined in

dist/smart-contract/contract.d.ts:517

Signature Verification Methods

checkMultiSig

▸ checkMultiSig(signatures, publickeys): boolean

Compares the first signature against each public key until it finds an ECDSA match. Starting with the subsequent public key, it compares the second signature against each remaining public key until it finds an ECDSA match. The process is repeated until all signatures have been checked or not enough public keys remain to produce a successful result. All signatures need to match a public key. Because public keys are not checked again if they fail any signature comparison, signatures must be placed in the scriptSig using the same order as their corresponding public keys were placed in the scriptPubKey or redeemScript. If all signatures are valid, 1 is returned, 0 otherwise. Due to a bug, one extra unused value is removed from the stack.

Onchain

See

https://wiki.bitcoinsv.io/index.php/Opcodes_used_in_Bitcoin_Script

Parameters

Name	Type
`signatures`	`Sig`[]
`publickeys`	`PubKey`[]

Returns

boolean

Defined in

dist/smart-contract/contract.d.ts:286

checkSig

▸ checkSig(signature, publickey, errorMsg?): boolean

A built-in function verifies an ECDSA signature. It takes two inputs from the stack, a public key (on top of the stack) and an ECDSA signature in its DER_CANONISED format concatenated with sighash flags. It outputs true or false on the stack based on whether the signature check passes or fails.

Onchain

See

https://wiki.bitcoinsv.io/index.php/Opcodes_used_in_Bitcoin_Script

Parameters

Name	Type
`signature`	`Sig`
`publickey`	`PubKey`
`errorMsg?`	`string`

Returns

boolean

Defined in

dist/smart-contract/contract.d.ts:246

Class: SmartContract

Table of contents​

Constructors​

Properties​

Accessors​

Other Methods​

Signature Verification Methods​

Constructors​

constructor​

Parameters​

Defined in​

Properties​

call​

Defined in​

dummySignSingleCallTx​

Defined in​

from​

Defined in​

hasPrevouts​

Defined in​

multiContractCall​

Defined in​

signSingleCallTx​

Defined in​

singleContractCall​

Defined in​

to​

Defined in​

Accessors​

asmArgs​

Returns​

Defined in​

balance​

Returns​

Defined in​

changeAddress​

Returns​

Defined in​

changeAmount​

Returns​

Defined in​

codePart​

Returns​

Defined in​

ctx​

Returns​

Defined in​

dataPart​

Returns​

Defined in​

debug​

Returns​

Defined in​

lockingScript​

Returns​

Defined in​

methods​

Returns​

Defined in​

prevouts​

Returns​

Defined in​

provider​

Returns​

Defined in​

scriptHash​

Returns​

Defined in​

scriptSize​

Returns​

Defined in​

signer​

Returns​

Defined in​

utxo​

Returns​

Defined in​

Other Methods​

bindTxBuilder​

Parameters​

Table of contents

Constructors

Properties

Accessors

Other Methods

Signature Verification Methods

Constructors

constructor

Parameters

Defined in

Properties

call

Defined in

dummySignSingleCallTx

Defined in

from

Defined in

hasPrevouts

Defined in

multiContractCall

Defined in

signSingleCallTx

Defined in

singleContractCall

Defined in

to

Defined in

Accessors

asmArgs

Returns

Defined in

balance

Returns

Defined in

changeAddress

Returns

Defined in

changeAmount

Returns

Defined in

codePart

Returns

Defined in

ctx

Returns

Defined in

dataPart

Returns

Defined in

debug

Returns

Defined in

lockingScript

Returns

Defined in

methods

Returns

Defined in

prevouts

Returns

Defined in

provider

Returns

Defined in

scriptHash

Returns

Defined in

scriptSize

Returns

Defined in

signer

Returns

Defined in

utxo

Returns

Defined in

Other Methods

bindTxBuilder

Parameters

Returns