Mesh: the TypeScript SDK for Cardano

Build Cardano dApps in TypeScript: transactions, wallets, smart contracts and blockchain data in one open-source SDK.

Website & live demos · API docs · Guides · Examples · Discord

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Mesh is an open-source TypeScript and JavaScript SDK for building applications on the Cardano blockchain. It handles the hard parts of Cardano development, such as coin selection, fee calculation, CBOR serialization and script evaluation, so you can focus on your app.

With Mesh you can:

• Build transactions with MeshTxBuilder: send ADA and native tokens, mint and burn NFTs, stake, vote in governance, and spend from Plutus and Aiken scripts.
• Connect wallets in the browser through CIP-30 (such as Eternl) with BrowserWallet, or sign server-side from a mnemonic or private key with MeshWallet.
• Use ready-made smart contracts for escrow, marketplaces, vesting, swaps and more, each with on-chain code and off-chain TypeScript.
• Query and submit through Blockfrost, Koios, Maestro, Ogmios, Yaci and other blockchain providers.
• Test offline against a local ledger with the Scalus emulator.

Mesh runs in Node.js, the browser, Next.js and other modern frameworks.

Quick start

Create a new Cardano dApp from a template with the Mesh CLI:

npx meshjs your-app-name

Or add Mesh to an existing project:

npm install @meshsdk/core

Example: send ADA from a browser wallet

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

const provider = new BlockfrostProvider("<BLOCKFROST_PROJECT_ID>");
const wallet = await BrowserWallet.enable("eternl");

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

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

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

Try this and many more transactions interactively in the Mesh playground.

Packages

This monorepo publishes the core Mesh packages to npm under the @meshsdk scope. Most apps only need @meshsdk/core, which re-exports transactions, wallets, providers and common utilities.

Package	Description	Docs
@meshsdk/core	The main entry point. Re-exports transactions, wallets, providers and common utilities.	Playground
@meshsdk/transaction	MeshTxBuilder for sending assets, minting tokens and interacting with smart contracts	Docs · Playground
@meshsdk/contract	Open-source smart contracts with off-chain transaction code	Docs · Playground
@meshsdk/common	Shared constants, types and interfaces used across the SDK	Docs
@meshsdk/core-cst	Serialization and utilities built on cardano-js-sdk and Harmonic Labs libraries	Docs
@meshsdk/core-csl	Serialization and utilities built on Whisky (cardano-serialization-lib)	Docs
@meshsdk/scalus-emulator	Local Cardano ledger emulator built on Scalus, for testing transactions offline

Packages in other repositories

These @meshsdk packages are developed in their own repositories:

Package	Description	Repository
@meshsdk/wallet	Browser (CIP-30) and headless wallets for managing keys, signing and submitting	MeshJS/wallet
@meshsdk/provider	Blockchain data providers (Blockfrost, Koios, Maestro, Ogmios and more)	MeshJS/providers
@meshsdk/react	React components and hooks for Cardano wallet connection	MeshJS/react
@meshsdk/hydra	Hydra Head protocol client for layer-2 scaling	MeshJS/hydra
@meshsdk/midnight-setup	Development setup for Midnight Network dApps	MeshJS/midnight-setup
@meshsdk/midnight-contracts-wizard	CLI wizard for new Midnight contract projects	MeshJS/midnight-contracts-wizard

Architecture

graph TD
  core["@meshsdk/core"]
  common["@meshsdk/common"]
  core_csl["@meshsdk/core-csl"]
  core_cst["@meshsdk/core-cst"]
  provider["@meshsdk/provider"]
  transaction["@meshsdk/transaction"]
  wallet["@meshsdk/wallet"]
  contract["@meshsdk/contract"]
  emulator["@meshsdk/scalus-emulator"]
  whisky["@sidan-lab/whisky-js"]
  cardano_sdk["@cardano-sdk/*"]
  harmoniclabs["@harmoniclabs/*"]

  contract --> core
  core --> provider
  core --> transaction
  core --> wallet
  core --> core_cst
  wallet --> transaction
  transaction --> core_cst
  emulator --> core_cst

  subgraph serializers
    core_csl --> whisky
    core_cst --> cardano_sdk
    core_cst --> harmoniclabs
  end

  core_cst --> common
  core_csl --> common

  click core_csl "https://docs.meshjs.dev/core-csl" _parent
  click core_cst "https://docs.meshjs.dev/core-cst" _parent
  click provider "https://github.com/MeshJS/providers" _parent
  click transaction "https://docs.meshjs.dev/transactions" _parent
  click wallet "https://github.com/MeshJS/wallet" _parent
  click contract "https://docs.meshjs.dev/contracts" _parent

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Cardano smart contracts library

@meshsdk/contract includes open-source Cardano smart contracts, each with on-chain Aiken code, off-chain TypeScript, documentation and a live demo.

Contract	What it does	Links
Content Ownership	A registry where users create content that is recorded on-chain	Demo · Source · Docs
Escrow	Holds assets between two parties until both agree to complete the exchange	Demo · Source · Docs
Giftcard	Locks assets behind a newly minted gift card token; redeeming burns the token and releases the assets	Demo · Source · Docs
Hello World	A simple lock-and-unlock contract to learn end-to-end validation and transaction building	Demo · Source · Docs
Marketplace	An NFT marketplace where anyone can list, buy and sell native assets	Demo · Source · Docs
NFT Minting Machine	Mints NFTs with an index that increments by one for each new token	Demo · Source · Docs
Payment Splitter	Splits incoming payments among a group of addresses	Demo · Source · Docs
Swap	Exchanges assets between two parties	Demo · Source · Docs
Vesting	Locks tokens until a set time, after which the beneficiary can withdraw them	Demo · Source · Docs
Asteria (work in progress)	A bot challenge where ships race across a 2D grid to showcase the eUTxO model	Source
Royalties (work in progress)	CIP-102 royalties for NFTs	Source · Docs

Developing Mesh

Mesh is a Turborepo monorepo using npm workspaces. You need Node.js 18 or later.

git clone https://github.com/MeshJS/mesh.git
cd mesh
npm install
npm run build

Command	What it does
npm run build	Build all packages
npm run dev	Build packages in watch mode
npm test	Run the test suites
npm run lint	Lint all packages
npm run format	Check formatting with Prettier (format:fix to apply)

Contributing

Contributions of all kinds are welcome: bug fixes, new features, documentation, tests, and help triaging issues and pull requests.

• Read the contributing guide and Code of Conduct.
• See the developer docs for coding and pull request guidelines.
• Report bugs and request features in GitHub issues, or ask questions on Discord.

Using an AI coding assistant? MeshJS/skills gives Claude Code, Cursor, Codex and other tools deep knowledge of the Mesh SDK.

License

Mesh is released under the Apache 2.0 License.