Fee Grants

Using the fee grant module to let one account pay fees for another

Cosmos SDK’s fee grant module allows one account (the granter) to pay transaction fees on behalf of another account (the grantee). This is useful for onboarding users who don’t yet hold tokens.

Sending a Transaction with a Fee Grant

Set the granter field on the StdFee object:

import { coins } from "@cosmjs/proto-signing";

const fee = {
  amount: coins(5000, "uatom"),
  gas: "200000",
  granter: "cosmos1granter...",
};

const result = await client.signAndBroadcast(granteeAddress, messages, fee);

The granter must have previously granted a fee allowance to the grantee on-chain (using MsgGrantAllowance).

Querying Fee Allowances

Use the feegrant query extension to check existing grants:

import {
  QueryClient,
  setupFeegrantExtension,
} from "@cosmjs/stargate";
import { connectComet } from "@cosmjs/tendermint-rpc";

const cometClient = await connectComet("https://rpc.my-chain.network");
const queryClient = QueryClient.withExtensions(
  cometClient,
  setupFeegrantExtension,
);

const allowance = await queryClient.feegrant.allowance(
  "cosmos1granter...",
  "cosmos1grantee...",
);

const allAllowances = await queryClient.feegrant.allowances(
  "cosmos1grantee...",
);