effect-v4-migration

Migrate TypeScript projects from Effect v3 to Effect v4 module layout.

1|Updated Nov 28, 2025

Search Tags:#typescript #refactoring #migration #effect-ts #code upgrade #effect v4

Ready to run

npx skills add https://github.com/jlcanela/app-project-v2 --skill effect-v4-migration

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: effect-v4-migration
Source: https://github.com/jlcanela/app-project-v2/tree/main/.agents/skills/effect-v4-migration
Command: npx skills add https://github.com/jlcanela/app-project-v2 --skill effect-v4-migration

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill assists developers in migrating their TypeScript projects from older versions of Effect-TS (v3 and @effect/* v0.x) to the latest Effect v4, ensuring compatibility and leveraging new features.

Core Features & Use Cases

Import Path Updates: Automatically adjusts import statements to the new Effect v4 module layout.
API Renaming and Restructuring: Modifies code to accommodate changes in Effect's API, classes, and module organization.
Use Case: You have a project using @effect/platform and older Effect imports. This Skill can help you update all necessary imports and API calls to work seamlessly with Effect v4.

Quick Start

Migrate the provided Effect v3 code snippet to Effect v4.

Frequently Asked Questions about effect-v4-migration

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I migrate Effect v3 code to Effect v4?▼

Migrating Effect v3 to v4 involves updating import paths to the new module layout and adjusting changed APIs. This process preserves type safety and applies minimal mechanical changes based on the official Effect migration guide.

What changes when upgrading @effect/* packages to v4?▼

Upgrading @effect/* v0.x packages to Effect v4 involves API renaming, class restructuring, and module organization changes. You must modify code to accommodate these API adjustments and update all necessary imports to work seamlessly with the new v4 architecture.

Can I automatically update Effect TS imports to the new v4 module layout?▼

Yes, you can automatically adjust TypeScript import statements to match the new Effect v4 module layout. This import path update is a core feature of the migration process, transitioning from older Effect v3 structures to the new v4 architecture.

Does migrating to Effect v4 preserve existing TypeScript type safety?▼

Migrating to Effect v4 preserves TypeScript type safety by applying minimal mechanical code changes. The process focuses on updating imports and adjusting changed APIs across Effect, platform, schema, and HTTP modules without breaking type constraints.

What is the best way to handle API renaming when upgrading to Effect v4?▼

The best way to handle API renaming during an Effect v4 upgrade is to apply minimal mechanical changes based on the official migration guide. You modify code to accommodate changes in Effect's API, classes, and module organization while preserving type safety.

Why do my @effect/platform imports break after upgrading to Effect v4?▼

@effect/platform imports break after upgrading to Effect v4 because the new version introduces a different module layout and API restructuring. You must update all necessary import paths and API calls to work seamlessly with the new v4 architecture.