Create an Asset Token

Create a six-decimal B20 Asset token with issuer roles, a supply ceiling, and issuer-defined metadata. This example configures a stock token.

Use the B20 Asset variant to represent a class of tokenized shares with configurable precision, issuer roles, supply controls, and metadata. This example creates Example Corp Class A (EXM) with six decimals.

Real-world asset (RWA) tokenization is one of many use cases for the B20 Asset standard. The examples on this page use a stock token for illustration; the same flows apply to other asset types.

Tokenized securities examples shown for illustration. Base is a general-purpose blockchain; issuance and compliance are the responsibility of the issuer under applicable law.

Demo

The demo uses a local browser-generated account to submit real transactions on Base Vibenet. If Vibenet or its B20 features are unavailable, it automatically switches to an illustrative offline version.

New to B20? See the B20 Token Standard for the concepts and a full launch walkthrough. These samples target base-std@be6d045, viem@2.55.11, and Base Foundry v1.1.1.

Create and Verify the Stock Token

Choose the Asset variant when you need configurable decimals, announcements, a scheduled UI multiplier, extra metadata, or batchMint. Asset decimals must be in the range [6, 18]; values outside that range revert InvalidDecimals. The type is sealed into the token address at creation and cannot change.

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 createStockToken() {
  const salt = keccak256(stringToBytes("example-class-a-v1"));
  const params = encodeAbiParameters(
    parseAbiParameters("(uint8 version,string name,string symbol,address initialAdmin,uint8 decimals)"),
    [{ version: 1, name: "Example Corp Class A", symbol: "EXM", initialAdmin: account.address, decimals: 6 }],
  );
  const initCalls = ["MINT_ROLE", "BURN_BLOCKED_ROLE", "PAUSE_ROLE", "UNPAUSE_ROLE", "OPERATOR_ROLE"].map(
    (name) => encodeFunctionData({ abi: b20Abi, functionName: "grantRole", args: [role(name), account.address] }),
  );
  const receipt = await sendContract({ address: B20_FACTORY, abi: factoryAbi, functionName: "createB20", args: [0, salt, params, initCalls] });
  const [created] = parseEventLogs({ abi: factoryAbi, logs: receipt.logs, eventName: "B20Created" });
  return created.args.token;
}

The factory assigns a deterministic address from (variant, sender, salt). Address byte [10] is 0x00 for Asset tokens. Reusing the same (variant, sender, salt) triple reverts TokenAlreadyExists. Optional initCalls, such as the role grants above, run on the new token in the same transaction. The factory drops access after createB20 returns.

See the B20 token standard for the complete interface, roles, and policies.

The factory emits B20Created for the Asset variant and returns the deterministic token address.

The supply cap is a technical ceiling, not a representation of authorized or outstanding shares.

See Also

Issue Shares

Mint asset units to holders.

Restrict Eligible Holders

Gate who can hold with policies.