Treasury Updates Metadata (TS/JS + Fetch)

An example of a CIP-68 NFT where a central treasury wallet updates the on-chain metadata, using TypeScript or JavaScript.

This example requires several utility and configuration files. Create the following files in the same directory as your main script.

Need to create wallets?

You can use the Anvil Wallet CLI to generate the required wallet JSON files for these examples.

https://github.com/Cardano-Forge/anvil-api-examples/blob/main/utils/constant.ts

// See Authentication page for API key details.
export const X_API_KEY = "testnet_EyrkvCWDZqjkfLSe1pxaF0hXxUcByHEhHuXIBjt9";
export const NETWORK = "preprod";
export const API_URL = `https://${NETWORK}.api.ada-anvil.app/v2/services`;
export const HEADERS = {
  "Content-Type": "application/json",
  "x-api-key": X_API_KEY,
};

You will also need the shared utility functions, which you can find in the utils/shared.ts file in the examples repository.

This example uses the Wallet Endpoints to fetch UTXOs from the treasury wallet.

Now, you can run the main script:

https://github.com/Cardano-Forge/anvil-api-examples/blob/main/documentation-references/cip68-treasury-update-meta.ts

/**
 * CIP-68 Metadata Update with Treasury-Paid Fees Example
 *
 * This script demonstrates how to update the metadata of a CIP-68 asset (specifically the reference token)
 * where the transaction fees are paid from a designated treasury wallet.
 *
 * This involves:
 * 1. Loading treasury, policy, and metadata manager wallets.
 * 2. Defining the target asset and policy details.
 * 3. Fetching UTXOs from the treasury wallet to cover transaction fees.
 * 4. Building a transaction payload to update the CIP-68 metadata.
 * 5. Building the transaction via the Anvil API.
 * 6. Signing the transaction with both the metadata manager's key (as required by the reference token's datum)
 *    and the treasury wallet's key (to authorize fee payment).
 * 7. Submitting the fully signed transaction to the blockchain.
 *
 * Required files: wallet-treasury.json, wallet-policy.json, wallet-meta-manager.json
 * Required environment variables: BLOCKFROST_PROJECT_ID, ANVIL_API_KEY
 * Prerequisite: deno run --allow-all --env-file=.env cip68-treasury-update-meta.ts
 */

import { Buffer } from "node:buffer";
import {
  FixedTransaction,
  PrivateKey,
} from "npm:@emurgo/[email protected]";
import {
  createNativeScript,
  timeToSlot,
  getKeyhash,
} from "../utils/shared.ts";
import { API_URL, HEADERS } from "../utils/constant.ts";
import { getUtxos } from "../fetch-utxos-from-the-backend/utxos/blockfrost.ts";

// 1. Load wallets
const treasuryWallet = JSON.parse(Deno.readTextFileSync("wallet-treasury.json"));
const policyWallet = JSON.parse(Deno.readTextFileSync("wallet-policy.json"));
const metaManagerWallet = JSON.parse(Deno.readTextFileSync("wallet-meta-manager.json"));

// 2. Define Asset and Policy Details
// This is the hex-encoded asset name (policyID + assetName) of the CIP-68 token pair.
// The API will automatically find the reference (100) token to update.
const assetName = "000643b0616e76696c61706963697036385f31373532373032393939373838";

// The native script is needed to be pre-loaded for the API to validate the transaction.
// In a real-world scenario, you might just have the policy ID if it's already on-chain.
const expirationDate = "2026-01-01";
const slot = await timeToSlot(new Date(expirationDate));
const keyhash = await getKeyhash(policyWallet.base_address_preprod);
if (!keyhash) {
  throw new Error("Unable to get key hash for policy wallet.");
}
const nativeScript = await createNativeScript(keyhash, slot);

// 3. Fetch Treasury UTXOs
const BLOCKFROST_PROJECT_ID = Deno.env.get("BLOCKFROST_PROJECT_ID");
if (!BLOCKFROST_PROJECT_ID) {
  throw new Error("Missing BLOCKFROST_PROJECT_ID env var");
}
const utxos = await getUtxos(
  "https://cardano-preprod.blockfrost.io/api/v0",
  BLOCKFROST_PROJECT_ID,
  treasuryWallet.base_address_preprod,
);
console.log(`Found ${utxos.length} UTXOs in treasury wallet.`);

// 4. Build the transaction payload
const buildBody = {
  changeAddress: treasuryWallet.base_address_preprod,
  utxos,
  cip68MetadataUpdates: [
    {
      policyId: nativeScript.hash,
      assetName: assetName,
      metadata: {
        name: "New Updated Name",
        description: "This is the updated description for the CIP-68 asset.",
        image: "ipfs://new-image-hash-goes-here",
      },
      action: "update",
    },
  ],
  preloadedScripts: [
    {
      type: "simple",
      script: nativeScript.script,
      hash: nativeScript.hash,
    },
  ],
};

console.log("Build Body: ", buildBody);

// 5. Build the transaction
const buildResponse = await fetch(`${API_URL}/transactions/build`, {
  method: "POST",
  body: JSON.stringify(buildBody),
  headers: HEADERS,
});
const buildJson = await buildResponse.json();

if (!buildResponse.ok) {
  console.error("Build failed. Response:", buildJson);
  throw new Error(`Failed to build transaction: ${buildResponse.statusText}`);
}
console.log("Build Output:", buildJson);

// 6. Sign the transaction
const transaction = FixedTransaction.from_bytes(
  Buffer.from(buildJson.complete, "hex"),
);

// Sign with MetaManager wallet (required by the datum on the reference token)
transaction.sign_and_add_vkey_signature(PrivateKey.from_bech32(metaManagerWallet.skey));

// Sign with Treasury wallet (to authorize spending the UTXO for fees)
transaction.sign_and_add_vkey_signature(PrivateKey.from_bech32(treasuryWallet.skey));

// 7. Submit the transaction
const submitResponse = await fetch(`${API_URL}/transactions/submit`, {
  method: "POST",
  body: JSON.stringify({
    transaction: transaction.to_hex(),
  }),
  headers: HEADERS,
});
const submitJson = await submitResponse.json();

if (!submitResponse.ok) {
  console.error("Submission failed. Response:", submitJson);
  throw new Error(`Failed to submit transaction: ${submitResponse.statusText}`);
}

console.log("Submitted Transaction:", JSON.stringify(submitJson, null, 2));

/*
Sample Output: 

Found 3 UTXOs in treasury wallet.
Build Body:  {
  changeAddress: "addr_test1qpxpar5s94wv6n76jvmvkr8uhnrflge6fatjzlkuujw3m33mk0alnas44ptzrkqqp3kdhplmcwys5mlht5w6seefrtls2r748e",
  utxos: [
    "82825820cbdd371aca5fef27267d5a41d9af6c6d9c9ba46b16aa5501f6fae91d3415a1f700825839004c1e8e902d5ccd4fda9336cb0cfcbcc69fa33a4f57217edce49d1dc63bb3fbf9f615a85621d8000c6cdb87fbc3890a6ff75d1da867291aff1a05f5e100",
    "82825820f3c3344a570042a0ad5753bd6af8a6ff360dbc41ea35c77f6502da89427efc9c00825839004c1e8e902d5ccd4fda9336cb0cfcbcc69fa33a4f57217edce49d1dc63bb3fbf9f615a85621d8000c6cdb87fbc3890a6ff75d1da867291aff1a01312d00",
    "82825820d6aefd369f3bf1c17398c43a7608d197cba623f7fa60831f77865a9c76ecd56602825839004c1e8e902d5ccd4fda9336cb0cfcbcc69fa33a4f57217edce49d1dc63bb3fbf9f615a85621d8000c6cdb87fbc3890a6ff75d1da867291aff821a097f845ca3581c38fdf893232baf9703e2f051ff9083a2756063c8bce3d80eb8d5eb3fa148000de1407465737401581c5e3817eacf8b6c393307fa61b00d546678e24414380dc7a2d879bc78a148000de1407465737401581cf8e024681ee83f54bd5f9a033464168f619970289017a9f53454d950a148000de1407465737401"
  ],
  cip68MetadataUpdates: [
    {
      policyId: "4d5bd6249f0d9e4b2762ce334e2973dc7fd414ec1e08b4b0c2159bfb",
      assetName: "000643b0616e76696c61706963697036385f31373532373032393939373838",
      metadata: {
        name: "New Updated Name",
        description: "This is the updated description for the CIP-68 asset.",
        image: "ipfs://new-image-hash-goes-here"
      },
      action: "update"
    }
  ],
  preloadedScripts: [
    {
      type: "simple",
      script: { type: "all", scripts: [ [Object], [Object] ] },
      hash: "4d5bd6249f0d9e4b2762ce334e2973dc7fd414ec1e08b4b0c2159bfb"
    }
  ]
}
Build Output: {
  hash: "3bbfdc451b2d12a3388146113b9411da603c205a835579a6e1397e696e04f0df",
  complete: "84a700d90102838258209d13e6fdec8ddae0b7e94e27100feb67d30ab13b7f284f8c672f662018e16ff101825820d6aefd369f3bf1c17398c43a7608d197cba623f7fa60831f77865a9c76ecd56600825820d6aefd369f3bf1c17398c43a7608d197cba623f7fa60831f77865a9c76ecd56602018383583900bd2c5bba13a4f58a8a1ffd15e7c4f759f562c2dd928e3bf555fca3cb20106f57def03022a0a9751c4189de03b16730536a231f56df898dd3821a00157084a1581c4d5bd6249f0d9e4b2762ce334e2973dc7fd414ec1e08b4b0c2159bfba1581f000643b0616e76696c61706963697036385f31373532373032393939373838015820a68af340c4deadbc6dfadf635d8e8145d2d5dcdedb06ae4b27a218d0b5823ef8a300581d60ea2cb2c69f72fc8e3c31f836de3d6877267bbdc50311c3e8eecf099c011a00186a00028201d8184a49616e76696c2d746167825839004c1e8e902d5ccd4fda9336cb0cfcbcc69fa33a4f57217edce49d1dc63bb3fbf9f615a85621d8000c6cdb87fbc3890a6ff75d1da867291aff821a0979d543a3581c38fdf893232baf9703e2f051ff9083a2756063c8bce3d80eb8d5eb3fa148000de1407465737401581c5e3817eacf8b6c393307fa61b00d546678e24414380dc7a2d879bc78a148000de1407465737401581cf8e024681ee83f54bd5f9a033464168f619970289017a9f53454d950a148000de1407465737401021a00036529031a05c887fd081a05c86bdd0b5820ff3e6f8c66bcd5a36e6ad36d70bc96873d98e0684e0f1cae68023aa5c20a18e70ed9010281581cea2cb2c69f72fc8e3c31f836de3d6877267bbdc50311c3e8eecf099ca200d90102818258208bc6baaa47db83c0a0d957d559e4b443a9f7a5757ab3c184cf8c2b2ee21bb69558404800f8b668617063b0ecd1cee7760b205d2071ea97b5726c9ec89bcf90db00e2e2b4b8560aa2aae47eab657839e99fe997f17c4703d2ab2da4d778fe0659d40f04d901029fd8799fa3446e616d65504e65772055706461746564204e616d654b6465736372697074696f6e583554686973206973207468652075706461746564206465736372697074696f6e20666f7220746865204349502d36382061737365742e45696d616765581f697066733a2f2f6e65772d696d6167652d686173682d676f65732d6865726501fffff5f6",
  stripped: "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",
  witnessSet: "a200d90102818258208bc6baaa47db83c0a0d957d559e4b443a9f7a5757ab3c184cf8c2b2ee21bb69558404800f8b668617063b0ecd1cee7760b205d2071ea97b5726c9ec89bcf90db00e2e2b4b8560aa2aae47eab657839e99fe997f17c4703d2ab2da4d778fe0659d40f04d901029fd8799fa3446e616d65504e65772055706461746564204e616d654b6465736372697074696f6e583554686973206973207468652075706461746564206465736372697074696f6e20666f7220746865204349502d36382061737365742e45696d616765581f697066733a2f2f6e65772d696d6167652d686173682d676f65732d6865726501ffff"
}
Submitted Transaction: {
  "txHash": "3bbfdc451b2d12a3388146113b9411da603c205a835579a6e1397e696e04f0df"
}
*/

Learn More

For a step-by-step explanation, see the Update CIP-68 Metadata Guide.