Mint Supply - Base Documentation

When fiat lands in reserves, mint matching supply. Minting is gated by MINT_ROLE, and an optional supply cap keeps circulation from exceeding your reserves.

Demo

New to B20? See the B20 Token Standard for the concepts and a full launch walkthrough. These samples target base-std@v1.0.0, viem@2.55.11, and Base Foundry v1.1.1.

Mint and verify supply

import { parseUnits, type Address } from "viem";
import { publicClient } from "../../shared/clients.js";
import { b20Abi } from "../abi.js";
import { sendContract } from "../write.js";

export async function mintAndVerify(token: Address, holder: Address) {
  const amount = parseUnits("1000", 6);
  await sendContract({ address: token, abi: b20Abi, functionName: "mint", args: [holder, amount] });
  const balance = await publicClient.readContract({ address: token, abi: b20Abi, functionName: "balanceOf", args: [holder] });
  if (balance < amount) throw new Error("Minted balance was not recorded");
  return balance;
}

    function mintStablecoin(address token, address holder) public {
        IB20(token).mint(holder, 1_000e6);
        require(IB20(token).balanceOf(holder) >= 1_000e6, "mint not recorded");
    }

base-cast send "$TOKEN_ADDRESS" "mint(address,uint256)" "$HOLDER" 1000000000 \
  --rpc-url "$RPC_URL" --private-key "$PRIVATE_KEY"
base-cast call "$TOKEN_ADDRESS" "balanceOf(address)(uint256)" "$HOLDER" --rpc-url "$RPC_URL"

See the complete verified B20 examples for imports, client construction, and runnable projects.

The holder balance increases by 1,000,000,000 base units, or 1,000 MUSD.

The caller needs MINT_ROLE, the recipient must pass MINT_RECEIVER_POLICY, and the mint must remain under the supply cap.

See also

Burn supply
Mint and Supply cap in the B20 standard

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