Node API Overview

Use the Node API for low-level access to Alchemy-supported blockchains

Intro

The Node API is our implementation of the standard JSON-RPC API defined by Ethereum. It also supports reading and writing data for non-EVM chains like Solana and Bitcoin.

Use the Node API if you want to access the standard low-level interface for reading and writing to the blockchain of your choosing. For specific use cases and higher levels of abstraction, Alchemy also offers:

  • indexed speciality endpoints (ie. NFTs, Tokens, Transfers), use our Data API.
  • account abstraction and smart wallet flows, use our Wallet API.

Components of Node API

  • Chain APIs: read/write interface for all blockchains supported by Alchemy.
  • Websockets: otherwise known as our Subscription API, for subscribing to pending transactions, log events, new blocks and more.
  • Trace API: for insights into transactions processing and onchain activity.
  • Debug API: access to non-standard RPC methods for inspecting and debugging transactions.

When Should I Use the Node API?

Use the Node API when your app needs direct, low-level access to blockchain data and functionality without relying on Alchemy’s smart wallet abstractions or indexed data services.

Writing to a Blockchain

Use the Node API if:

  • Your users are sending transactions, and you’re not using Alchemy Smart Wallets.
    • If You are using our wallets, check out the Wallet API, which supports:
      • sendUserOp
      • estimateUserOpGas
      • and more account abstraction features

Examples of Node API write use cases

  • Sending ETH and ERC-20 tokens to/from users
  • Buying/selling NFTs in a marketplace
  • Simulating and inspecting transactions
  • Writing custom smart contract interactions

Key Node API endpoints

  • eth_sendRawTransaction - Submits a raw transaction (serialized and signed) for broadcasting to the network.

Reading from a Blockchain

If your use case requires raw blockchain data, not indexed data like in our Data API, then the Node API is what you want:

Examples of Node API read use cases

  • Reading token balances
  • Polling logs and events

Key endpoints

  • eth_getBalance - Returns the balance of the account of a given address.
  • eth_getLogs - Returns an array of all logs matching the specified filter.
  • eth_estimateGas - Generates and returns an estimate of how much gas is necessary to allow the transaction to complete.
  • eth_call - Executes a new message call immediately without creating a transaction on the blockchain.

Summary

The Node API is right for you if you are looking for a low-level way to:

  • Send and/or simulate transactions
  • Read raw blockchain state
  • Build tools or apps close to node-level logic

Otherwise, consider the following APIs more optimized for higher-level abstractions:

  • Data API: for fast, enriched, indexed queries (ie. historical token balances)
  • Wallet API: for smart account flows (ie. account abstraction)