Getting Started

Install Delta and run your first code transformation in under 5 minutes.

Requirements

Node.js 18 or higher.

Install

npm install -g @delta-lang/cli

Verify:

delta --version

Your first transform

Create transform.delta in your project root:

fix strictNull {
  pattern:  { $X == null }
  replace:  { $X === null }
  scope:    "**/*.ts"
  severity: bug
  note:     "use strict equality"
}
apply fix strictNull to project preview

Preview:

delta run transform.delta --preview

Apply:

delta run transform.delta

CLI commands

CommandDescription
delta run <file>Run a .delta transform
delta run <file> --previewPreview — no files written
delta check <file>Parse and validate only
delta initScaffold a starter transform.delta
delta lsp --stdioStart the Language Server (used by VS Code)

VS Code extension

Install the vscode-delta extension for syntax highlighting, IntelliSense, and run commands directly in the editor.

Next steps