Guides

Deno & Fetch#

Quick-Start Example

This streamlined tutorial shows how to mint a CIP-68 NFT on Cardano using Deno + Fetch and the Anvil API.

We'll:

1. Load wallets (Customer, Policy, Metadata Manager)
2. Create a native script using our Native Script utilities
3. Build a mint payload that creates both tokens (100 + 222) in the same transaction.
4. Call transactions/build
5. Sign with the Policy & Customer (skeys) keys. Customer in the backend for simplicity.
6. Submit the transaction
7. Verify on-chain that the assets are minted:
   • The reference token is sent to the metadata manager wallet
   • The user token is sent to the customer wallet

Prerequisites#

Three Wallets – You'll need three wallets with these fields:

• Customer Wallet: Pays fees, receives user token (label 222)
  • base_address_preprod: Testnet address (addr_test1...)
  • skey: Signing key (ed25519e_sk1...)
• Policy Wallet: Controls minting policy
  • base_address_preprod: Testnet address (addr_test1...)
  • skey: Signing key (ed25519e_sk1...)
• Metadata Manager Wallet: Receives reference token (label 100)
  • base_address_preprod: Testnet address (addr_test1...)
  • skey: Signing key (optional for this script. Used when updating metadata)

Create wallets with our Wallet CLI. Ensure customer wallet has ADA for fees.

Anvil API Key – A valid Anvil API key. See Authentication.

Utility Helpers – Import helpers from the utilities-functions guide to keep this file short.

Project Structure#

For the absolute minimum setup, you only need:

your-project/
├── mint.ts                    # Main minting script
├── utils/
│   ├── shared.ts             # Utility functions (timeToSlot, getKeyhash, etc.)
│   └── constant.ts           # API configuration (URLs, headers)
├── wallet-customer.json      # Customer wallet (pays fees, receives user token)
├── wallet-policy.json        # Policy wallet (controls minting policy)
└── wallet-meta-manager.json  # Metadata manager wallet (receives reference token)

Quick-Start Script#

import { Buffer } from "node:buffer";
import {
  FixedTransaction,
  PrivateKey,
} from "npm:@emurgo/cardano-serialization-lib-nodejs@14.1.1";
import {
  timeToSlot,
  getKeyhash,
  createNativeScript,
} from "../utils/shared.ts";
import { API_URL, HEADERS } from "../utils/constant.ts";

// Load wallets
const customerWallet = JSON.parse(Deno.readTextFileSync("wallet-customer.json"));
const policyWallet = JSON.parse(Deno.readTextFileSync("wallet-policy.json"));
const metaManagerWallet = JSON.parse(Deno.readTextFileSync("wallet-meta-manager.json"));

// Create native script
const slot = await timeToSlot(new Date("2026-01-01"));
const keyhash = await getKeyhash(policyWallet.base_address_preprod);
const nativeScript = await createNativeScript(keyhash!, slot);

const counter = Date.now();
const assetName = `anvilapicip68_${counter}`;

// Build mint payload
const buildBody = {
  changeAddress: customerWallet.base_address_preprod,
  mint: [
    {
      // Reference token - label 100, sent to Metadata-Manager wallet
      version: "cip68",
      assetName: { name: assetName, format: "utf8", label: 100 },
      metadata: {
        name: `anvil-api-${counter}`,
        image: "ipfs://YOUR_IPFS_HASH_HERE",
        mediaType: "image/png",
        description: "Anvil API CIP-68 Mint Example",
      },
      policyId: nativeScript.hash,
      quantity: 1,
      destAddress: metaManagerWallet.base_address_preprod,
    },
    {
      // User token - label 222, sent to Customer wallet
      version: "cip68",
      assetName: { name: assetName, format: "utf8", label: 222 },
      policyId: nativeScript.hash,
      quantity: 1,
      destAddress: customerWallet.base_address_preprod,
    },
  ],
  preloadedScripts: [nativeScript],
};

// Build transaction
const buildResult = await fetch(`${API_URL}/transactions/build`, {
  method: "POST",
  headers: HEADERS,
  body: JSON.stringify(buildBody),
});
const buildJson = await buildResult.json();
if (!buildResult.ok) {
  throw new Error(buildJson.message);
}

// Sign transaction
const tx = FixedTransaction.from_bytes(Buffer.from(buildJson.complete, "hex"));
tx.sign_and_add_vkey_signature(PrivateKey.from_bech32(policyWallet.skey));

// Sign with customer wallet. Normally this would come from the clientside via your customers browser extenstion
// This is here for simplicity. See full minting examples below.
tx.sign_and_add_vkey_signature(PrivateKey.from_bech32(customerWallet.skey));

// Submit transaction
const submitResult = await fetch(`${API_URL}/transactions/submit`, {
  method: "POST",
  headers: HEADERS,
  body: JSON.stringify({ transaction: tx.to_hex() }),
});
const submitJson = await submitResult.json();
if (!submitResult.ok) {
  throw new Error(submitJson.message);
}

console.log("Submitted Transaction Hash:", submitJson.txHash);

Utility Files Reference#

You'll need to create the utility files. See the Utility Functions documentation for detailed API endpoint information and examples.

The utility files provide these key functions:

• timeToSlot(date) - Converts timestamps to Cardano slots
• getKeyhash(address) - Extracts payment key hash from addresses
• createNativeScript(keyHash, ttl) - Creates time-locked native scripts
• API configuration - Anvil API endpoints and headers

💡 Tip: The anvil-api-examples repository contains the most up-to-date utility functions and is the recommended source.

Running the Script#

# Run the script
deno run --allow-all mint.ts

Troubleshooting#

Common Issues#

Error: "Module not found"

• Check that your import paths match your project structure
• Ensure utils/shared.ts and utils/constant.ts exist

Error: "Failed to get key hash for address"

• Verify your wallet addresses are valid testnet addresses
• Check that wallet files contain proper JSON format
• Ensure addresses start with addr_test1

Error: "API call failed: Input validation failed"

• Usually means wallet address parsing failed
• Double-check wallet file format and addresses

Error: "Unable to build tx"

• Ensure customer wallet has sufficient ADA for fees
• Check that API key is valid
• Verify network connectivity

CIP-68 Specific Notes#

Two tokens are minted in the same transaction:

• Reference token (label 100) - Contains metadata, sent to metadata manager wallet
• User token (label 222) - The actual NFT, sent to customer wallet

Full Example Script#

For complete, fully-annotated examples see the examples repository:

CIP-68 Example

CIP-68 Treasury Pays Example