Providers are the bridge between your application and the Cardano blockchain. They handle data fetching, transaction submission, and blockchain queries so you can focus on building your application.

Overview

MeshJS supports multiple blockchain data providers, each with different strengths:

Provider	Best For	Key Features
Blockfrost	Production apps	100+ APIs, reliable infrastructure
Koios	Open-source projects	Free tier, distributed architecture
Maestro	DeFi applications	Enterprise-grade, turbo submit
UTxORPC	High performance	gRPC protocol, minimal overhead
Ogmios	Self-hosted nodes	WebSocket API, local deployment
Yaci	Local development	Custom devnets, fast iteration
Hydra	Layer 2 scaling	High throughput, low latency
Offline Fetcher	Testing	No network required, mock data
Offline Evaluator	Script testing	Plutus evaluation, cost analysis

Quick Start

Install MeshJS and choose a provider:

npm install @meshsdk/core

Initialize your provider:

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

const provider = new BlockfrostProvider("<YOUR_API_KEY>");

Use the provider to fetch blockchain data:

// Fetch UTxOs from an address
const utxos = await provider.fetchAddressUTxOs(
  "addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9"
);

// Fetch protocol parameters
const params = await provider.fetchProtocolParameters();

// Submit a transaction
const txHash = await provider.submitTx(signedTx);

Provider Interface

All providers implement a common interface, making them interchangeable:

interface IFetcher {
  fetchAccountInfo(address: string): Promise<AccountInfo>;
  fetchAddressUTxOs(address: string, asset?: string): Promise<UTxO[]>;
  fetchAssetAddresses(asset: string): Promise<AssetAddress[]>;
  fetchAssetMetadata(asset: string): Promise<AssetMetadata>;
  fetchBlockInfo(hash: string): Promise<BlockInfo>;
  fetchCollectionAssets(policyId: string, cursor?: number): Promise<CollectionAssets>;
  fetchProtocolParameters(epoch?: number): Promise<Protocol>;
  fetchTxInfo(hash: string): Promise<TransactionInfo>;
  fetchUTxOs(hash: string, index?: number): Promise<UTxO[]>;
}

interface ISubmitter {
  submitTx(tx: string): Promise<string>;
}

interface IEvaluator {
  evaluateTx(tx: string): Promise<Omit<Action, "data">[]>;
}