# OnchainForGasWrapper\ Defined in: [atomiq-sdk/src/swaps/trusted/onchain/OnchainForGasWrapper.ts:27](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/trusted/onchain/OnchainForGasWrapper.ts#L27) Trusted swap for Bitcoin -> Smart chains, to be used for minor amounts to get gas tokens on the destination chain, which is only needed for Solana, which still uses legacy swaps ## Extends * [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md)<`T`, `OnchainForGasSwapTypeDefinition`<`T`>, `OnchainForGasWrapperOptions`> ## Type Parameters | Type Parameter | | -------------------------------------------------------------------------------------------------------------------- | | `T` *extends* [`ChainType`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/type-aliases/ChainType.md) | ## Constructors ### Constructor ``` new OnchainForGasWrapper( chainIdentifier, unifiedStorage, unifiedChainEvents, chain, prices, tokens, btcRpc, lpApi, options, events?): OnchainForGasWrapper; ``` Defined in: [atomiq-sdk/src/swaps/trusted/onchain/OnchainForGasWrapper.ts:64](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/trusted/onchain/OnchainForGasWrapper.ts#L64) #### Parameters | Parameter | Type | Description | | -------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- | | `chainIdentifier` | `string` | | | `unifiedStorage` | [`UnifiedSwapStorage`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/UnifiedSwapStorage.md)<`T`> | Storage interface for the current environment | | `unifiedChainEvents` | `UnifiedSwapEventListener`<`T`> | On-chain event listener | | `chain` | `T`\[`"ChainInterface"`] | | | `prices` | [`ISwapPrice`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapPrice.md) | Pricing to use | | `tokens` | `WrapperCtorTokens` | | | `btcRpc` | [`BitcoinRpcWithAddressIndex`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/interfaces/BitcoinRpcWithAddressIndex.md)<`any`> | Bitcoin RPC which also supports getting transactions by txoHash | | `lpApi` | `IntermediaryAPI` | | | `options` | `OnchainForGasWrapperOptions` | | | `events?` | `EventEmitter`<{ `swapState`: \[[`ISwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwap.md)<[`ChainType`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/type-aliases/ChainType.md), `SwapTypeDefinition`<[`ChainType`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/type-aliases/ChainType.md), [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md)<[`ChainType`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/type-aliases/ChainType.md), `any`, `ISwapWrapperOptions`>, [`ISwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwap.md)<[`ChainType`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/type-aliases/ChainType.md), `any`, `any`>>, `number`>]; }> | Instance to use for emitting events | #### Returns `OnchainForGasWrapper`<`T`> #### Overrides [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`constructor`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#constructor) ## Properties ### chainIdentifier ``` readonly chainIdentifier: T["ChainId"]; ``` Defined in: [atomiq-sdk/src/swaps/ISwapWrapper.ts:164](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/ISwapWrapper.ts#L164) Chain identifier string of this wrapper #### Inherited from [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`chainIdentifier`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#chainidentifier) *** ### events ``` readonly events: EventEmitter<{ swapState: [OnchainForGasSwap]; }>; ``` Defined in: [atomiq-sdk/src/swaps/ISwapWrapper.ts:168](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/ISwapWrapper.ts#L168) Event emitter emitting `"swapState"` event when swap's state changes #### Inherited from [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`events`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#events) *** ### TYPE ``` readonly TYPE: TRUSTED_FROM_BTC = SwapType.TRUSTED_FROM_BTC; ``` Defined in: [atomiq-sdk/src/swaps/trusted/onchain/OnchainForGasWrapper.ts:28](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/trusted/onchain/OnchainForGasWrapper.ts#L28) Swap type #### Overrides [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`TYPE`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#type) ## Methods ### checkPastSwaps() ``` checkPastSwaps(pastSwaps?, noSave?): Promise<{ changedSwaps: OnchainForGasSwap[]; removeSwaps: OnchainForGasSwap[]; }>; ``` Defined in: [atomiq-sdk/src/swaps/ISwapWrapper.ts:424](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/ISwapWrapper.ts#L424) Runs checks on all the known pending swaps, syncing their state from on-chain data #### Parameters | Parameter | Type | Description | | ------------ | ------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- | | `pastSwaps?` | [`OnchainForGasSwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/OnchainForGasSwap.md)<`T`>\[] | Optional array of past swaps to check, otherwise all relevant swaps will be fetched from the persistent storage | | `noSave?` | `boolean` | Whether to skip saving the swap changes in the persistent storage | #### Returns `Promise`<{ `changedSwaps`: [`OnchainForGasSwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/OnchainForGasSwap.md)<`T`>\[]; `removeSwaps`: [`OnchainForGasSwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/OnchainForGasSwap.md)<`T`>\[]; }> #### Remarks Doesn't work properly if you pass non-persisted swaps #### Inherited from [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`checkPastSwaps`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#checkpastswaps) *** ### create() ``` create( recipient, amount, lpOrUrl, refundAddress?): Promise>; ``` Defined in: [atomiq-sdk/src/swaps/trusted/onchain/OnchainForGasWrapper.ts:89](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/trusted/onchain/OnchainForGasWrapper.ts#L89) Returns a newly created trusted Bitcoin on-chain -> Smart chain swap, receiving the specified amount of native token on the destination chain. #### Parameters | Parameter | Type | Description | | ---------------- | ------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------ | | `recipient` | `string` | Address of the recipient on the smart chain destination chain | | `amount` | `bigint` | Amount of native token to receive in base units | | `lpOrUrl` | `string` \| [`Intermediary`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/Intermediary.md) | Intermediary (LP) to use for the swap | | `refundAddress?` | `string` | Bitcoin address to receive refund on in case the intermediary (LP) cannot execute the swap | #### Returns `Promise`<[`OnchainForGasSwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/OnchainForGasSwap.md)<`T`>> *** ### init() ``` init(noTimers, noCheckPastSwaps): Promise; ``` Defined in: [atomiq-sdk/src/swaps/ISwapWrapper.ts:360](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/ISwapWrapper.ts#L360) Initializes the swap wrapper, needs to be called before any other action can be taken #### Parameters | Parameter | Type | Default value | Description | | ------------------ | --------- | ------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `noTimers` | `boolean` | `false` | Whether to skip scheduling a tick timer for the swaps, if the tick timer is not initiated the swap states depending on e.g. expiry can be out of sync with the actual expiration of the swap | | `noCheckPastSwaps` | `boolean` | `false` | Whether to skip checking past swaps on initialization (by default all pending swaps are re-checked on init, and their state is synchronized from the on-chain data) | #### Returns `Promise`<`void`> #### Inherited from [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`init`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#init) *** ### stop() ``` stop(): Promise; ``` Defined in: [atomiq-sdk/src/swaps/ISwapWrapper.ts:401](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/ISwapWrapper.ts#L401) Un-subscribes from event listeners on the smart chain, terminates the tick interval and stops this wrapper #### Returns `Promise`<`void`> #### Inherited from [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`stop`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#stop) *** ### tick() ``` tick(swaps?, abortSignal?): Promise; ``` Defined in: [atomiq-sdk/src/swaps/ISwapWrapper.ts:459](https://github.com/atomiqlabs/atomiq-sdk/blob/786509324f7f09c427e9ccfe527d82e496f06af5/src/swaps/ISwapWrapper.ts#L459) Invokes ISwap.\_tick on all the known swaps #### Parameters | Parameter | Type | Description | | -------------- | ------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | | `swaps?` | [`OnchainForGasSwap`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/OnchainForGasSwap.md)<`T`>\[] | Optional array of swaps to invoke `_tick()` on, otherwise all relevant swaps will be fetched from the persistent storage | | `abortSignal?` | `AbortSignal` | Abort signal | #### Returns `Promise`<`void`> #### Inherited from [`ISwapWrapper`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md).[`tick`](https://docs.atomiq.exchange/sdk-reference/api/atomiq-sdk/src/classes/ISwapWrapper.md#tick)