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)