Issue Your Stablecoin

Create a fiat-backed stablecoin on Base with one B20 factory call.

Create a fiat-backed token with one call to the B20 Factory, using the STABLECOIN variant. Decimals are fixed at 6, and the token carries an immutable ISO currency code.

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.

Create and verify the stablecoin

TypeScript

import { encodeAbiParameters, encodeFunctionData, keccak256, parseAbiParameters, parseEventLogs, stringToBytes } from "viem";
import { account } from "../../shared/clients.js";
import { B20_FACTORY, b20Abi, factoryAbi, role } from "../abi.js";
import { sendContract } from "../write.js";

export async function createStablecoin() {
  const salt = keccak256(stringToBytes("merchant-usd-v1"));
  const params = encodeAbiParameters(
    parseAbiParameters(
      "(uint8 version,string name,string symbol,address initialAdmin,string currency)",
    ),
    [{ version: 1, name: "Merchant USD", symbol: "MUSD", initialAdmin: account.address, currency: "USD" }],
  );
  const initCalls = [
    encodeFunctionData({
      abi: b20Abi,
      functionName: "grantRole",
      args: [role("MINT_ROLE"), account.address],
    }),
    encodeFunctionData({
      abi: b20Abi,
      functionName: "updateSupplyCap",
      args: [10_000_000n * 10n ** 6n],
    }),
  ];
  const receipt = await sendContract({
    address: B20_FACTORY,
    abi: factoryAbi,
    functionName: "createB20",
    args: [1, salt, params, initCalls],
  });
  const [created] = parseEventLogs({ abi: factoryAbi, logs: receipt.logs, eventName: "B20Created" });
  return created.args.token;
}

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

The factory emits B20Created, and the returned token address is ready for minting.

B20 tokens are open by default. Configure roles, policies, and the supply cap during creation before issuing value.

See also

• Mint supply · Restrict who can hold it
• Stablecoin variant in the B20 standard