Build Cardano applications with Mesh's comprehensive SDK for wallets, transactions, data handling, utilities, and x402 payments.

Overview

The Mesh SDK provides everything you need to build Cardano applications: wallet integrations, transaction builders, data serialization, utility functions, and x402 payments. Choose the APIs that fit your use case.

Quick Start

npm install @meshsdk/core

import { MeshTxBuilder, BlockfrostProvider } from "@meshsdk/core";
import { MeshCardanoBrowserWallet } from "@meshsdk/wallet";

// Connect to a browser wallet
const wallet = await MeshCardanoBrowserWallet.enable("eternl");

// Initialize provider and transaction builder
const provider = new BlockfrostProvider("<YOUR_API_KEY>");
const txBuilder = new MeshTxBuilder({ fetcher: provider });

// Build and submit a transaction
const utxos = await wallet.getUtxosMesh();
const changeAddress = await wallet.getChangeAddressBech32();

const unsignedTx = await txBuilder
  .txOut("addr_test1...", [{ unit: "lovelace", quantity: "5000000" }])
  .changeAddress(changeAddress)
  .selectUtxosFrom(utxos)
  .complete();

const signedTx = await wallet.signTx(unsignedTx, false);
const txHash = await wallet.submitTx(signedTx);

API Categories

Category	Purpose	Key Classes
Wallets	Connect and interact with user wallets	`MeshCardanoBrowserWallet`, `MeshCardanoHeadlessWallet`
Transaction Builder	Construct and customize transactions	`MeshTxBuilder`
Transaction Parser	Parse and test transaction data	`MeshTxParser`, `TxTester`
Data	Handle Cardano data types and conversions	`MeshValue`, JSON/Mesh formats
Utilities	Serialize, deserialize, and resolve data	Serializers, deserializers, resolvers
x402 Payments	Charge for an HTTP resource with Cardano	`fetchWithPayment`, `createPaywall`, `createFacilitatorApp`

Wallets

Connect to browser extension wallets (CIP-30) or create server-side wallets for backend applications.

// Browser wallet (frontend)
import { MeshCardanoBrowserWallet } from "@meshsdk/wallet";
const wallet = await MeshCardanoBrowserWallet.enable("eternl");

// Headless wallet (backend)
import { MeshCardanoHeadlessWallet, AddressType } from "@meshsdk/wallet";
const wallet = await MeshCardanoHeadlessWallet.fromMnemonic({
  networkId: 0,
  walletAddressType: AddressType.Base,
  fetcher: provider,
  mnemonic: ["..."],
});

Learn more about Wallets →

Transaction Builder

Build any type of Cardano transaction with fine-grained control over inputs, outputs, metadata, and scripts.

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

const txBuilder = new MeshTxBuilder({ fetcher: provider });

const unsignedTx = await txBuilder
  .txOut(recipient, [{ unit: "lovelace", quantity: "5000000" }])
  .mint("1", policyId, assetName)
  .mintingScript(forgingScript)
  .metadataValue(721, metadata)
  .changeAddress(changeAddress)
  .selectUtxosFrom(utxos)
  .complete();

Learn more about Transaction Builder →

Data Handling

Work with Cardano's data types and convert between different formats.

import { MeshValue, mConStr0 } from "@meshsdk/core";

// Work with multi-asset values
const value = new MeshValue();
value.addAsset({ unit: "lovelace", quantity: "5000000" });

// Create Plutus data
const datum = mConStr0([pubKeyHash]);

Learn more about Data APIs →

Utilities

Serialize addresses, deserialize transactions, and resolve various Cardano identifiers.

import {
  deserializeAddress,
  serializeNativeScript,
  resolveScriptHash
} from "@meshsdk/core";

// Get key hash from address
const { pubKeyHash } = deserializeAddress(address);

// Create and serialize a native script
const { address, scriptCbor } = serializeNativeScript(nativeScript);

// Get policy ID from script
const policyId = resolveScriptHash(forgingScript);

Learn more about Utilities →

x402 Payments

Charge for an API or page with @meshsdk/x402. The server answers 402 with a price, the client signs a Cardano payment, and a facilitator settles it before the content is released.

import { fetchWithPayment } from "@meshsdk/x402";

const { response, paymentResponse } = await fetchWithPayment(
  "http://localhost:3000/weather",
  undefined,
  wallet,
  { fetcher: provider, protocol, currentSlot },
);