ducphamle2 · October 23, 2024 06:17 · Oct 23, 2024
diff --git a/feegrant-osmosis.ts b/feegrant-osmosis.ts
@@ -0,0 +1,79 @@
+import { stringToPath } from '@cosmjs/crypto';
+import { coins, DirectSecp256k1HdWallet, EncodeObject } from '@cosmjs/proto-signing';
+import { SigningStargateClient, GasPrice } from '@cosmjs/stargate';
+import { OfflineDirectSigner } from '@keplr-wallet/types';
+import { PeriodicAllowance } from 'cosmjs-types/cosmos/feegrant/v1beta1/feegrant';
+import { MsgGrantAllowance } from 'cosmjs-types/cosmos/feegrant/v1beta1/tx';
+import dotenv from 'dotenv';
+dotenv.config();
+
+const numOfMsToExpiration = (numOfMs: number) => {
+    const dateNow = new Date();
+    const dateIn2Years = new Date(dateNow.getTime() + numOfMs);
+    const timeMS = dateIn2Years.getTime();
+    return {
+        seconds: BigInt(Math.round(timeMS / 1000)),
+        nanos: (timeMS % 1000) * 1e6,
+    };
+};
+
+export function createFeeGrantMsg(
+    granter: string,
+    grantee: string,
+    base: string,
+    decimals: number,
+    amount: bigint = 1n,
+): EncodeObject {
+    const periodicAllowance = PeriodicAllowance.fromPartial({
+        period: numOfMsToExpiration(100),
+        periodSpendLimit: coins((amount * 10n ** BigInt(decimals)).toString(), base),
+        periodCanSpend: coins((amount * 10n ** BigInt(decimals)).toString(), base),
+    });
+    const grantMsg = MsgGrantAllowance.fromPartial({
+        grantee,
+        granter,
+        allowance: {
+            typeUrl: PeriodicAllowance.typeUrl,
+            value: PeriodicAllowance.encode(periodicAllowance).finish(),
+        },
+    });
+    return {
+        typeUrl: MsgGrantAllowance.typeUrl,
+        value: grantMsg,
+    };
+}
+
+export async function getOfflineSignerAndSigningClient(
+    rpc: string,
+    prefix: string,
+    coinType: number,
+    gasPrice: string,
+): Promise<{ signer: OfflineDirectSigner; client: SigningStargateClient }> {
+    const signer = await DirectSecp256k1HdWallet.fromMnemonic(process.env.MNEMONIC, {
+        prefix,
+        hdPaths: [stringToPath(`m/44'/${coinType}'/0'/0/0`)],
+    });
+    const client = await SigningStargateClient.connectWithSigner(rpc, signer, {
+        gasPrice: GasPrice.fromString(gasPrice),
+    });
+
+    return { signer, client };
+}
+
+(async () => {
+    const { signer, client } = await getOfflineSignerAndSigningClient(
+        'https://osmosis.rpc.orai.io',
+        'osmo',
+        118,
+        '0.006uosmo',
+    );
+    const acc = (await signer.getAccounts())[0];
+    const message = createFeeGrantMsg(
+        acc.address,
+        'osmo14h0n2nlfrfz8tn9usfyjrxqd23fhj9a0zs2jvl',
+        'uosmo',
+        6,
+    );
+    const result = await client.signAndBroadcast(acc.address, [message], 'auto');
+    console.log(result);
+})();