Deno & Fetch

A Deno-based script for minting CIP-25 assets on the Cardano blockchain using the Anvil API. This script generates wallets, creates policies, customizes asset metadata, builds and signs transactions,

This a a very specific example, the goal is to show how flexible and versatile the Anvil API is.

This example will be entirely done into one file named index.ts

Objectives

Mint a CIP-25 Asset
Create a Policy (an NFT Collection)
Create a custom function to customize the asset metadata
Create 2 wallets, one for the policy and one to act as the customer
Submit transaction to the network
This is only an example showing the anvil api versatility
The example is built on Cardano Preprod

Code

Dependencies

import { Buffer } from "node:buffer";
import {
  Credential,
  type Ed25519KeyHash,
  FixedTransaction,
  NativeScript,
  NativeScripts,
  PrivateKey,
  ScriptAll,
  ScriptPubkey,
  TimelockExpiry,
} from "npm:@emurgo/cardano-serialization-lib-nodejs@13.2.0";

Import Helper Functions

To reduce the amount of content in this guide, you only have to import all functions defined here:

Cardano Wallets

~/Downloads/cardano-wallet-macos-latest --name policy --mnemonic
~/Downloads/cardano-wallet-macos-latest --name customer --mnemonic

Load wallets

// NOTE: Be sure to send ADA in this address, it will be used to pay the tx fee.
const customerWallet = JSON.parse(Deno.readTextFileSync("customer.json"));
// Wallet to create the policy with, no ADA is required for this one.
const policyWallet = JSON.parse(Deno.readTextFileSync("policy.json"));

Setup policy

Don't forget to increase the counter, otherwise you will double mint.

// Variables
const expirationDate = "2026-01-01";
const counter = 202502061237;

// Expiration date, you can interact with the policy until this date is reached.
// After that the policy is locked.
const slot = dateToSlot(new Date(expireDate));

const keyhash = get_keyhash(policyWallet.skey);
if (!keyhash) {
  throw new Error("Unable to get key hash for policy, missing or invalid skey");
}
const policyAnvilApi = create_policy_script(keyhash, slot);

Collection configurations

This example requires 2 rules.

const policyAnvilApiScript = {
  type: "all",
  scripts: [
    {
      type: "sig",
      keyHash: keyhash.to_hex(),
    },
    {
      type: "before",
      slot: slot,
    },
  ],
};

Meaning that the policy has to be signed by the wallet defined in the policy wallet path parameter AND all mutations must be done before the date defined.

Create Metadata

This function is where you have to define your own data and configuration per asset.

For example

const assets: {
  version: string;
  assetName: string;
  metadata: {
    name: string;
    image: string | string[];
    mediaType: string;
    description: string;
    epoch: number;
  };
  policyId: string;
  quantity: 1;
}[] = [];

const assetMetadataTemplate = JSON.parse(
  Deno.readTextFileSync("metatemplate.json")
);

// Simulate use case
assets.push({
  version: "cip25",
  assetName: `anvilapicip25_${counter}`,
  metadata: {
    ...assetMetadataTemplate,
    // Adding custom data just to test the flow
    name: `anvil-api-${counter}`,
    epoch: new Date().getTime(), // dummy data
  },
  policyId: get_policy_id(policyAnvilApi.mint_script),
  quantity: 1,
});

The counter is used to be sure that the assetName remains unique.

Create the transaction

const data = {
  changeAddress: customerWallet.enterprise_address_preprod,
  mint: assets,
  preloadedScripts: [
    {
      type: "simple",
      script: policyAnvilApiScript,
      hash: get_policy_id(policyAnvilApi.mint_script),
    },
  ],
};

const urlTX =
  "https://preprod.api.ada-anvil.app/v2/services/transactions/build";
const transactionToSignWithPolicyKey = await fetch(urlTX, {
  method: "POST",
  body: JSON.stringify(data),
  headers: {
    "Content-Type": "application/json",
    "X-Api-Key": "testnet_EyrkvCWDZqjkfLSe1pxaF0hXxUcByHEhHuXIBjt9",
  },
}).then((res) => res.json());

Sign with the policy wallet

// Sign transaction with policy key
const transactionToSignWithCustomerKey = FixedTransaction.from_bytes(
  Buffer.from(transactionToSignWithPolicyKey.complete, "hex")
);
transactionToSignWithCustomerKey.sign_and_add_vkey_signature(
  PrivateKey.from_bech32(policyWallet.skey)
);

Sign with the customer wallet

usually done using the browser extension

// Sign transaction with metaManager key
const txToSubmitOnChain = FixedTransaction.from_bytes(
  Buffer.from(transactionToSignWithCustomerKey.to_hex(), "hex")
);
// This sign the tx and add vkeys to the txToSubmitOnChain, so in submit we don't need to provide signautres
txToSubmitOnChain.sign_and_add_vkey_signature(
  PrivateKey.from_bech32(customerWallet.skey)
);

Submit Transaction

const urlSubmit =
  "https://preprod.api.ada-anvil.app/v2/services/transactions/submit";

const submitted = await fetch(urlSubmit, {
  method: "POST",
  body: JSON.stringify({
    signatures: [], // This empty because the txToSubmitOnChain has the vkeys
    transaction: txToSubmitOnChain.to_hex(),
  }),
  headers: {
    "Content-Type": "application/json",
    "X-Api-Key": "testnet_EyrkvCWDZqjkfLSe1pxaF0hXxUcByHEhHuXIBjt9",
  },
}).then((res) => res.json());

console.debug(submitted);

Launch Deno

deno run -A index.ts

Dont forget to increase the counter, otherwise you will double mint.

File Content - (customer.json, policy.json, metatemplate.json)

customer.json

{
  "skey": "REDACTED",
  "skey_hex": "REDACTED",
  "pkey": "REDACTED",
  "pkey_hex": "REDACTED",
  "key_hash": "REDACTED",
  "base_address_preview": "addr_test1qqc0f6py9qeyp5k2vme7pxct0t0ut5mczmq8yfumx8cfpfx7kdf62usuu92g463pyumktcckmd9x7nmrvfxc9w04dnfqz7ycf9",
  "base_address_preprod": "addr_test1qqc0f6py9qeyp5k2vme7pxct0t0ut5mczmq8yfumx8cfpfx7kdf62usuu92g463pyumktcckmd9x7nmrvfxc9w04dnfqz7ycf9",
  "base_address_mainnet": "addr1qyc0f6py9qeyp5k2vme7pxct0t0ut5mczmq8yfumx8cfpfx7kdf62usuu92g463pyumktcckmd9x7nmrvfxc9w04dnfqpgec96",
  "enterprise_address_mainnet": "addr1vyc0f6py9qeyp5k2vme7pxct0t0ut5mczmq8yfumx8cfpfq5xuxsn",
  "enterprise_address_preview": "addr_test1vqc0f6py9qeyp5k2vme7pxct0t0ut5mczmq8yfumx8cfpfq0wg6lk",
  "enterprise_address_preprod": "addr_test1vqc0f6py9qeyp5k2vme7pxct0t0ut5mczmq8yfumx8cfpfq0wg6lk",
  "reward_address_mainnet": "stake1u80tx5a9wgwwz4y2agsjwdm9uvtdkjn0fa3kynvzh86ke5se4shkt",
  "reward_address_preview": "stake_test1ur0tx5a9wgwwz4y2agsjwdm9uvtdkjn0fa3kynvzh86ke5s7l64jk",
  "reward_address_preprod": "stake_test1ur0tx5a9wgwwz4y2agsjwdm9uvtdkjn0fa3kynvzh86ke5s7l64jk",
  "mnemonic": "REDACTED"
}

policy.json

{
  "skey": "REDACTED",
  "skey_hex": "REDACTED",
  "pkey": "REDACTED",
  "pkey_hex": "REDACTED",
  "key_hash": "REDACTED",
  "base_address_preview": "addr_test1qzmdaaddmhut3e3kyjsv5f3nsws0mcxk7tu2gpwql8f8pfschsxexl9yakag0rdpf7m4rgg4dvlwuzklghq7trdr4qkqpckdye",
  "base_address_preprod": "addr_test1qzmdaaddmhut3e3kyjsv5f3nsws0mcxk7tu2gpwql8f8pfschsxexl9yakag0rdpf7m4rgg4dvlwuzklghq7trdr4qkqpckdye",
  "base_address_mainnet": "addr1qxmdaaddmhut3e3kyjsv5f3nsws0mcxk7tu2gpwql8f8pfschsxexl9yakag0rdpf7m4rgg4dvlwuzklghq7trdr4qkqzwtdgx",
  "enterprise_address_mainnet": "addr1vxmdaaddmhut3e3kyjsv5f3nsws0mcxk7tu2gpwql8f8pfsc3x6e8",
  "enterprise_address_testnet": "addr_test1vzmdaaddmhut3e3kyjsv5f3nsws0mcxk7tu2gpwql8f8pfsrejxkz",
  "reward_address_mainnet": "stake1uyvtcrvn0jjwmw583ks5ld635y2kk0hwpt05ts093k36stqfn5cxe",
  "reward_address_testnet": "stake_test1uqvtcrvn0jjwmw583ks5ld635y2kk0hwpt05ts093k36stqwe76zy",
  "mnemonic": "REDACTED"
}

metatemplate.json

{
  "name": "TBD",
  "image": [
    "https://ada-anvil.s3.ca-central-1.amazonaws.com/",
    "logo_pres_V2_3.png"
  ],
  "mediaType": "image/png",
  "description": "Testing CIP-25 using anvil API"
}

The code will override the name key

Explorer

The Whole File (Deno Version)

index.ts

import { Buffer } from "node:buffer";
import {
  Credential,
  type Ed25519KeyHash,
  FixedTransaction,
  NativeScript,
  NativeScripts,
  PrivateKey,
  ScriptAll,
  ScriptPubkey,
  TimelockExpiry,
} from "npm:@emurgo/cardano-serialization-lib-nodejs@13.2.0";

//
// Utils
//
const dateToSlot = (date: Date) => {
  return Math.floor(date.getTime() / 1000) - 1596491091 + 4924800;
};

export function get_keyhash(private_key: string): Ed25519KeyHash | undefined {
  return Credential.from_keyhash(
    PrivateKey.from_bech32(private_key).to_public().hash()
  ).to_keyhash();
}

export function create_policy_script(
  policy_key_hash: Ed25519KeyHash,
  ttl: number,
  with_timelock = true
): { mint_script: NativeScript; policy_ttl: number } {
  const scripts = NativeScripts.new();
  const key_hash_script = NativeScript.new_script_pubkey(
    ScriptPubkey.new(policy_key_hash)
  );
  scripts.add(key_hash_script);

  const policy_ttl: number = ttl;

  if (with_timelock) {
    const timelock = TimelockExpiry.new(policy_ttl);
    const timelock_script = NativeScript.new_timelock_expiry(timelock);
    scripts.add(timelock_script);
  }

  const mint_script = NativeScript.new_script_all(ScriptAll.new(scripts));

  return { mint_script, policy_ttl };
}

export function bytes_to_hex(input: Uint8Array): string {
  return Buffer.from(input).toString("hex");
}

export function get_policy_id(mint_script: NativeScript): string {
  return bytes_to_hex(mint_script.hash().to_bytes());
}

//
// Wallets
//
// NOTE: Be sure to send ADA in this address, it will be used to pay the tx fee.
const customerWallet = JSON.parse(Deno.readTextFileSync("customer.json"));
// Wallet to create the policy with, no ADA is required for this one.
const policyWallet = JSON.parse(Deno.readTextFileSync("policy.json"));

//
// Variables
//
const expirationDate = "2026-01-01";
const counter = 202502061;

//
// Set Policy
//
// Date before you can interact with the policy
const slot = dateToSlot(new Date(expirationDate));
const keyhash = get_keyhash(policyWallet.skey);
if (!keyhash) {
  throw new Error("Unable to get key hash for policy, missing or invalid skey");
}
const policyAnvilApi = create_policy_script(keyhash, slot);

//
// Custom for each mint collection
//
// Not the best way to handle this, a config file would be better
const policyAnvilApiScript = {
  type: "all",
  scripts: [
    {
      type: "sig",
      keyHash: keyhash.to_hex(),
    },
    {
      type: "before",
      slot: slot,
    },
  ],
};

const assets: {
  version: string;
  assetName: string;
  metadata: {
    name: string;
    image: string | string[];
    mediaType: string;
    description: string;
    epoch: number;
  };
  policyId: string;
  quantity: 1;
}[] = [];
const assetMetadataTemplate = JSON.parse(
  Deno.readTextFileSync("metatemplate.json")
);

// Simulate use case
assets.push({
  version: "cip25",
  assetName: `anvilapicip25_${counter}`,
  metadata: {
    ...assetMetadataTemplate,
    // Adding custom data just to test the flow
    name: `anvil-api-${counter}`,
    epoch: new Date().getTime(), // dummy data
  },
  policyId: get_policy_id(policyAnvilApi.mint_script),
  quantity: 1,
});

//
// Generic calls to create, sign and submit tx
//
const data = {
  changeAddress: customerWallet.enterprise_address_preprod,
  mint: assets,
  preloadedScripts: [
    {
      type: "simple",
      script: policyAnvilApiScript,
      hash: get_policy_id(policyAnvilApi.mint_script),
    },
  ],
};

const urlTX =
  "https://preprod.api.ada-anvil.app/v2/services/transactions/build";
const transactionToSignWithPolicyKey = await fetch(urlTX, {
  method: "POST",
  body: JSON.stringify(data),
  headers: {
    "Content-Type": "application/json",
    "X-Api-Key": "testnet_EyrkvCWDZqjkfLSe1pxaF0hXxUcByHEhHuXIBjt9",
  },
}).then((res) => res.json());

console.debug(
  "transactionToSignWithPolicyKey: ",
  transactionToSignWithPolicyKey
);
//
// policy signature
//
const transactionToSignWithCustomerKey = FixedTransaction.from_bytes(
  Buffer.from(transactionToSignWithPolicyKey.complete, "hex")
);
transactionToSignWithCustomerKey.sign_and_add_vkey_signature(
  PrivateKey.from_bech32(policyWallet.skey)
);

console.debug(
  "transactionToSignWithCustomerKey: ",
  transactionToSignWithCustomerKey.to_hex()
);

//
// customer signature
//
const txToSubmitOnChain = FixedTransaction.from_bytes(
  Buffer.from(transactionToSignWithCustomerKey.to_hex(), "hex")
);
console.debug("Customer Wallet", customerWallet);
// This sign the tx and add vkeys to the txToSubmitOnChain, so in submit we don't need to provide signautres
txToSubmitOnChain.sign_and_add_vkey_signature(
  PrivateKey.from_bech32(customerWallet.skey)
);

console.debug("txToSubmitOnChain: ", txToSubmitOnChain.to_hex());
console.debug(
  "txToSubmitOnChain JSON: ",
  txToSubmitOnChain.witness_set().to_json()
);

//
// Submit tx
//
const urlSubmit =
  "https://preprod.api.ada-anvil.app/v2/services/transactions/submit";

const submitted = await fetch(urlSubmit, {
  method: "POST",
  body: JSON.stringify({
    signatures: [], // This empty because the txToSubmitOnChain has the vkeys
    transaction: txToSubmitOnChain.to_hex(),
  }),
  headers: {
    "Content-Type": "application/json",
    "X-Api-Key": "testnet_EyrkvCWDZqjkfLSe1pxaF0hXxUcByHEhHuXIBjt9",
  },
}).then((res) => res.json());

console.debug(submitted);

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