Solana Kit Migration Assistant

This skill helps you navigate the transition between @solana/web3.js (v1.x) and @solana/kit (formerly web3.js 2.0), providing guidance on when to use each library and how to migrate between them.

Overview

The Solana JavaScript ecosystem has two major SDK options:

| Library | Status | Use Case |
|---------|--------|----------|
| @solana/web3.js (1.x) | Maintenance mode | Legacy projects, Anchor-dependent apps |
| @solana/kit | Active development | New projects, performance-critical apps |

Key Decision: @solana/kit is the future, but migration isn't always straightforward.

When to Use Each Library

Use @solana/kit When:

Starting a new project without Anchor dependencies

Bundle size matters - Kit is tree-shakeable (26% smaller bundles)

Performance is critical - ~200ms faster confirmation latency, 10x faster crypto ops

Using standard programs (System, Token, Associated Token)

Building browser applications where bundle size impacts load time

Type safety is important - Better TypeScript support catches errors at compile time

Using modern JavaScript - Native BigInt, WebCrypto, AsyncIterators

Use @solana/web3.js (v1.x) When:

Using Anchor - Anchor doesn't support Kit out of the box yet

Existing large codebase - Migration cost outweighs benefits

Dependencies require v1 - Check if your SDKs support Kit

Rapid prototyping - v1's OOP style may be more familiar

Documentation/examples - More community resources for v1

Use Both (Hybrid Approach) When:

Gradual migration - Use @solana/compat for interoperability

Mixed dependencies - Some libs require v1, some support Kit

Feature-by-feature migration - Convert hot paths first

Quick Decision Flowchart

```
START
│
├─ New project? ─────────────────────────────────────────┐
│ │ │
│ ├─ Using