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Utilities

Resolvers

Convert between different Cardano data formats including hashes, addresses, epochs, and slots

Use resolver functions to convert between different Cardano data formats. These utilities handle conversions for private keys, transaction hashes, data hashes, script hashes, addresses, epochs, and slots.

Overview

Resolvers provide format conversion utilities for common Cardano operations:

  • Key derivation (mnemonic to private key)
  • Hash computation (transactions, data, scripts)
  • Address extraction (stake addresses, key hashes)
  • Time-based conversions (epoch and slot numbers)

Quick Start

import { resolveDataHash, resolvePaymentKeyHash, resolveEpochNo } from "@meshsdk/core";

// Compute a data hash
const hash = resolveDataHash("my-datum-value");

// Extract a key hash from an address
const keyHash = resolvePaymentKeyHash("addr_test1qpvx0sac...");

// Get the current epoch
const epoch = resolveEpochNo("preprod");

resolvePrivateKey

Derive a private key from mnemonic phrases.

Function Signature

resolvePrivateKey(mnemonic: string[]): string

Parameters

ParameterTypeRequiredDescription
mnemonicstring[]YesArray of 24 mnemonic words

Returns

TypeDescription
stringThe derived private key in hex format

Example

import { resolvePrivateKey } from "@meshsdk/core";

const mnemonic = [
  "solution", "solution", "solution", "solution",
  "solution", "solution", "solution", "solution",
  "solution", "solution", "solution", "solution",
  "solution", "solution", "solution", "solution",
  "solution", "solution", "solution", "solution",
  "solution", "solution", "solution", "solution",
];

const privateKey = resolvePrivateKey(mnemonic);
console.log("Private Key:", privateKey);

resolveTxHash

Compute the transaction hash from a CBOR-encoded transaction.

Function Signature

resolveTxHash(txCbor: string): string

Parameters

ParameterTypeRequiredDescription
txCborstringYesThe transaction in CBOR hex format (signed or unsigned)

Returns

TypeDescription
stringThe transaction hash (64 hex characters)

Example

import { resolveTxHash, MeshTxBuilder } from "@meshsdk/core";

const txBuilder = new MeshTxBuilder();

const unsignedTx = await txBuilder
  .txOut("addr_test1vpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0c7e4cxr", [
    { unit: "lovelace", quantity: "1500000" },
  ])
  .changeAddress(changeAddress)
  .selectUtxosFrom(utxos)
  .complete();

// Get hash before signing
const hash1 = resolveTxHash(unsignedTx);
console.log("Transaction Hash:", hash1);

// Hash remains the same after signing
const signedTx = await wallet.signTx(unsignedTx);
const hash2 = resolveTxHash(signedTx);

console.log("Hashes match:", hash1 === hash2); // true

resolveDataHash

Compute the hash of a datum value.

Function Signature

resolveDataHash(datum: any): string

Parameters

ParameterTypeRequiredDescription
datumanyYesThe datum value to hash

Returns

TypeDescription
stringThe datum hash (64 hex characters)

Example

import { resolveDataHash } from "@meshsdk/core";

// Simple string datum
const hash = resolveDataHash("supersecretdatum");
console.log("Datum Hash:", hash);

// Complex datum structure
const complexDatum = {
  constructor: 0,
  fields: [
    "aa048e4cc8a1e67e1d97ffbd4be614388014cbc2b2451527202943b6",
    1000000,
  ],
};
const complexHash = resolveDataHash(complexDatum);
console.log("Complex Datum Hash:", complexHash);

resolvePaymentKeyHash

Extract the payment key hash from a bech32 address.

Function Signature

resolvePaymentKeyHash(address: string): string

Parameters

ParameterTypeRequiredDescription
addressstringYesA Cardano bech32 address

Returns

TypeDescription
stringThe payment key hash (56 hex characters)

Example

import { resolvePaymentKeyHash, NativeScript } from "@meshsdk/core";

const address = "addr_test1vpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0c7e4cxr";
const keyHash = resolvePaymentKeyHash(address);

// Use in a native script
const nativeScript: NativeScript = {
  type: "sig",
  keyHash: keyHash,
};

console.log("Key Hash:", keyHash);

resolveNativeScriptHash

Compute the hash (policy ID) of a native script.

Function Signature

resolveNativeScriptHash(nativeScript: NativeScript): string

Parameters

ParameterTypeRequiredDescription
nativeScriptNativeScriptYesThe native script object

Returns

TypeDescription
stringThe script hash / policy ID (56 hex characters)

Example

import { resolveNativeScriptHash, resolvePaymentKeyHash, NativeScript } from "@meshsdk/core";

const keyHash = resolvePaymentKeyHash(
  "addr_test1vpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0c7e4cxr"
);

const nativeScript: NativeScript = {
  type: "all",
  scripts: [
    {
      type: "sig",
      keyHash: keyHash,
    },
  ],
};

const policyId = resolveNativeScriptHash(nativeScript);
console.log("Policy ID:", policyId);

resolveScriptHash

Compute the hash of a script from its CBOR representation.

Function Signature

resolveScriptHash(scriptCbor: string): string

Parameters

ParameterTypeRequiredDescription
scriptCborstringYesThe script in CBOR hex format

Returns

TypeDescription
stringThe script hash (56 hex characters)

Example

import { resolveScriptHash } from "@meshsdk/core";

const scriptCbor = "8200581c5867c3b8e27840f556ac268b781578b14c5661fc63ee720dbeab663f";

const hash = resolveScriptHash(scriptCbor);
console.log("Script Hash:", hash);

resolveRewardAddress

Convert a wallet address to its corresponding stake/reward address.

Function Signature

resolveRewardAddress(address: string): string

Parameters

ParameterTypeRequiredDescription
addressstringYesA Cardano base address with stake credential

Returns

TypeDescription
stringThe stake/reward address in bech32 format

Example

import { resolveRewardAddress } from "@meshsdk/core";

const walletAddress = "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9";

const stakeAddress = resolveRewardAddress(walletAddress);
console.log("Stake Address:", stakeAddress);
// Output: stake_test1urw5s...

resolveStakeKeyHash

Extract the stake key hash from a stake address.

Function Signature

resolveStakeKeyHash(stakeAddress: string): string

Parameters

ParameterTypeRequiredDescription
stakeAddressstringYesA stake address in bech32 format

Returns

TypeDescription
stringThe stake key hash (56 hex characters)

Example

import { resolveStakeKeyHash } from "@meshsdk/core";

const stakeAddress = "stake_test1uzw5mnt7g4xjgdqkfa80hrk7kdvds6sa4k0vvgjvlj7w8eskffj2n";

const stakeKeyHash = resolveStakeKeyHash(stakeAddress);
console.log("Stake Key Hash:", stakeKeyHash);

resolveFingerprint

Compute the asset fingerprint (CIP-14) from a policy ID and asset name.

Function Signature

resolveFingerprint(policyId: string, assetName: string): string

Parameters

ParameterTypeRequiredDescription
policyIdstringYesThe policy ID (56 hex characters)
assetNamestringYesThe asset name in hex format

Returns

TypeDescription
stringThe asset fingerprint (starts with asset1...)

Example

import { resolveFingerprint } from "@meshsdk/core";

const policyId = "426117329844ccb3b0ba877220ff06a5bdf21eab3fb33e2f3a3f8e69";
const assetName = "4d657368546f6b656e"; // "MeshToken" in hex

const fingerprint = resolveFingerprint(policyId, assetName);
console.log("Asset Fingerprint:", fingerprint);
// Output: asset1...

resolveScriptHashDRepId

Convert a script hash to a DRep ID for governance.

Function Signature

resolveScriptHashDRepId(scriptHash: string): string

Parameters

ParameterTypeRequiredDescription
scriptHashstringYesThe script hash (56 hex characters)

Returns

TypeDescription
stringThe DRep ID in bech32 format

Example

import { resolveScriptHashDRepId, resolveNativeScriptHash, NativeScript } from "@meshsdk/core";

const script: NativeScript = {
  type: "all",
  scripts: [
    {
      type: "sig",
      keyHash: "aa048e4cc8a1e67e1d97ffbd4be614388014cbc2b2451527202943b6",
    },
  ],
};

const scriptHash = resolveNativeScriptHash(script);
const drepId = resolveScriptHashDRepId(scriptHash);
console.log("DRep ID:", drepId);

resolveEpochNo

Get the epoch number for a network at a specific time.

Function Signature

resolveEpochNo(network: string, milliseconds?: number): number

Parameters

ParameterTypeRequiredDescription
networkstringYesNetwork name: "mainnet", "preprod", or "preview"
millisecondsnumberNoOptional timestamp in milliseconds. Defaults to current time

Returns

TypeDescription
numberThe epoch number

Example: Get Current Epoch

import { resolveEpochNo } from "@meshsdk/core";

const currentEpoch = resolveEpochNo("preprod");
console.log("Current Epoch:", currentEpoch);

Example: Get Future Epoch

import { resolveEpochNo } from "@meshsdk/core";

// Calculate epoch one year from now
const oneYearFromNow = new Date();
oneYearFromNow.setFullYear(oneYearFromNow.getFullYear() + 1);

const futureEpoch = resolveEpochNo("preprod", oneYearFromNow.getTime());
console.log("Epoch in 1 year:", futureEpoch);

resolveSlotNo

Get the slot number for a network at a specific time.

Function Signature

resolveSlotNo(network: string, milliseconds?: number): number

Parameters

ParameterTypeRequiredDescription
networkstringYesNetwork name: "mainnet", "preprod", or "preview"
millisecondsnumberNoOptional timestamp in milliseconds. Defaults to current time

Returns

TypeDescription
numberThe slot number

Example: Get Current Slot

import { resolveSlotNo } from "@meshsdk/core";

const currentSlot = resolveSlotNo("preprod");
console.log("Current Slot:", currentSlot);

Example: Time-Locked Transaction

import { resolveSlotNo, MeshTxBuilder } from "@meshsdk/core";

// Lock transaction until 1 hour from now
const oneHourFromNow = Date.now() + 60 * 60 * 1000;
const validFromSlot = resolveSlotNo("preprod", oneHourFromNow);

const txBuilder = new MeshTxBuilder();
await txBuilder
  .txOut(recipientAddress, [{ unit: "lovelace", quantity: "5000000" }])
  .invalidBefore(validFromSlot)
  .changeAddress(changeAddress)
  .selectUtxosFrom(utxos)
  .complete();

Complete Example

This example demonstrates using multiple resolvers in a complete workflow:

import {
  resolvePaymentKeyHash,
  resolveNativeScriptHash,
  resolveDataHash,
  resolveRewardAddress,
  resolveFingerprint,
  resolveEpochNo,
  resolveSlotNo,
  serializeNativeScript,
  NativeScript,
} from "@meshsdk/core";

// 1. Extract key hash from address
const walletAddress = "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9";
const keyHash = resolvePaymentKeyHash(walletAddress);
console.log("Payment Key Hash:", keyHash);

// 2. Create and hash a native script
const nativeScript: NativeScript = {
  type: "all",
  scripts: [
    { type: "sig", keyHash: keyHash },
    { type: "after", slot: resolveSlotNo("preprod").toString() },
  ],
};

const policyId = resolveNativeScriptHash(nativeScript);
console.log("Policy ID:", policyId);

// 3. Serialize the script to get an address
const { address } = serializeNativeScript(nativeScript, 0);
console.log("Script Address:", address);

// 4. Get stake address
const stakeAddress = resolveRewardAddress(walletAddress);
console.log("Stake Address:", stakeAddress);

// 5. Compute asset fingerprint
const assetName = "4d657368546f6b656e";
const fingerprint = resolveFingerprint(policyId, assetName);
console.log("Asset Fingerprint:", fingerprint);

// 6. Hash some datum
const datumHash = resolveDataHash({ owner: keyHash, amount: 1000000 });
console.log("Datum Hash:", datumHash);

// 7. Get current epoch and slot
console.log("Current Epoch:", resolveEpochNo("preprod"));
console.log("Current Slot:", resolveSlotNo("preprod"));

Troubleshooting

resolvePrivateKey returns unexpected value

Ensure you provide exactly 24 valid BIP-39 mnemonic words in the correct order. The words must be from the standard BIP-39 English wordlist.

resolveRewardAddress fails

The input address must be a base address that includes a stake credential. Enterprise addresses (without stake credentials) cannot be converted to reward addresses.

Epoch/slot numbers seem incorrect

Verify you are using the correct network name ("mainnet", "preprod", or "preview"). Each network has different genesis parameters affecting epoch and slot calculations.

Deserializers

Parse CBOR and bech32 encoded Cardano data into usable objects

Data

Parse and manipulate Cardano data types for smart contract development

On this page

OverviewQuick StartresolvePrivateKeyFunction SignatureParametersReturnsExampleresolveTxHashFunction SignatureParametersReturnsExampleresolveDataHashFunction SignatureParametersReturnsExampleresolvePaymentKeyHashFunction SignatureParametersReturnsExampleresolveNativeScriptHashFunction SignatureParametersReturnsExampleresolveScriptHashFunction SignatureParametersReturnsExampleresolveRewardAddressFunction SignatureParametersReturnsExampleresolveStakeKeyHashFunction SignatureParametersReturnsExampleresolveFingerprintFunction SignatureParametersReturnsExampleresolveScriptHashDRepIdFunction SignatureParametersReturnsExampleresolveEpochNoFunction SignatureParametersReturnsExample: Get Current EpochExample: Get Future EpochresolveSlotNoFunction SignatureParametersReturnsExample: Get Current SlotExample: Time-Locked TransactionComplete ExampleTroubleshootingresolvePrivateKey returns unexpected valueresolveRewardAddress failsEpoch/slot numbers seem incorrectRelated