What is Avalanche® JS?
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Written by H
Updated over a week ago

AvalancheJS is a JavaScript library for building dApps on Avalanche®. AvalancheJS enables interactions with Avalanche APIs and has a modular library architecture, allowing for custom virtual machines to write plugins to extend AvalancheJS’s functionality. The library has helped hundreds of thousands of developers with building Web3 front-ends for Avalanche and Avalanche Subnets.

The APIs currently supported by default are:

  • Admin API

  • Auth API

  • AVM API (X-Chain)

  • EVM API (C-Chain)

  • Health API

  • Index API

  • Info API

  • Keystore API

  • Metrics API

  • PlatformVM API

  • Socket API

We built AvalancheJS with ease of use in mind. With this library, any Javascript developer is able to interact with a node on the Avalanche Platform that has enabled their API endpoints for the developer’s consumption. We keep the library up-to-date with the latest changes in the Avalanche Platform Specification found in the Platform Chain Specification, Exchange Chain (X-Chain) Specification, and Contract Chain (C-Chain) Specification.

Using AvalancheJS, developers can:

  • Locally manage private keys

  • Retrieve balances on addresses

  • Get UTXOs for addresses

  • Build and sign transactions

  • Issue signed transactions to the X-Chain, P-Chain, and C-Chain on the Primary network

  • Create a Subnetwork

  • Swap AVAX and assets between the X-Chain, P-Chain, and C-Chain

  • Add a Validator to the Primary network

  • Add a Delegator to the Primary network

  • Administer a local node

  • Retrieve Avalanche network information from a node


AvalancheJS requires Node.js version 14.18.0 or higher to compile.

For any additional questions, please view our other knowledge base articles or contact a support team member via the chat button. Examples are for illustrative purposes only.

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