Add methods for private transactions (#132)

src/alchemy-apis/types.ts

@@ -213,3 +213,7 @@ export interface RawContract {
   address: string | null;
   decimal: string | null;
 }
+
+export interface PrivateTransactionPreferences {
+  fast: boolean | null;
+}

src/index.ts

@@ -13,6 +13,7 @@ import {
   GetNftsParamsWithoutMetadata,
   GetNftsResponse,
   GetNftsResponseWithoutMetadata,
+  PrivateTransactionPreferences,
   TokenAllowanceParams,
   TokenAllowanceResponse,
   TokenBalancesResponse,
@@ -33,6 +34,7 @@ import { callWhenDone } from "./util/promises";
 import { makeAlchemyContext } from "./web3-adapter/alchemyContext";
 import { patchEnableCustomRPC } from "./web3-adapter/customRPC";
 import { patchEthMaxPriorityFeePerGasMethod } from "./web3-adapter/eth_maxPriorityFeePerGas";
+import { patchEthPrivateTransactionMethods } from "./web3-adapter/eth_PrivateTransactions";
 import { RestPayloadSender } from "./web3-adapter/sendRestPayload";
 
 export * from "./alchemy-apis/types";
@@ -131,6 +133,16 @@ export interface AlchemyEth extends Eth {
   getMaxPriorityFeePerGas(
     callback?: (error: Error, fee: string) => void,
   ): Promise<string>;
+  sendPrivateTransaction(
+    tx: string,
+    maxBlockNumber?: string,
+    preferences?: PrivateTransactionPreferences,
+    callback?: (error: Error, hash: string) => void,
+  ): Promise<string>;
+  cancelPrivateTransaction(
+    txHash: string,
+    callback?: (error: Error, result: boolean) => void,
+  ): Promise<boolean>;
 }
 
 interface EthereumWindow extends Window {
@@ -238,6 +250,7 @@ export function createAlchemyWeb3(
   patchSubscriptions(alchemyWeb3);
   patchEnableCustomRPC(alchemyWeb3);
   patchEthMaxPriorityFeePerGasMethod(alchemyWeb3);
+  patchEthPrivateTransactionMethods(alchemyWeb3);
   return alchemyWeb3;
 }
 

src/web3-adapter/eth_PrivateTransactions.ts

@@ -0,0 +1,13 @@
+export function patchEthPrivateTransactionMethods(web3: any): void {
+  web3.eth.customRPC({
+    name: "sendPrivateTransaction",
+    call: "eth_sendPrivateTransaction",
+    params: 3,
+  });
+
+  web3.eth.customRPC({
+    name: "cancelPrivateTransaction",
+    call: "eth_cancelPrivateTransaction",
+    params: 1,
+  });
+}