# @stackline/deepmerge

Secure, immutable, zero-dependency deep merge for JavaScript with a
deepmerge-compatible API.

## Canonical resources

- Documentation: https://alexandro.net/docs/vanilla/deepmerge/
- npm: https://www.npmjs.com/package/@stackline/deepmerge
- Source: https://github.com/alexandroit/stackline-deepmerge
- README: https://github.com/alexandroit/stackline-deepmerge/blob/main/README.md
- Security: https://github.com/alexandroit/stackline-deepmerge/blob/main/SECURITY.md
- Full LLM reference: https://alexandro.net/docs/vanilla/deepmerge/llms-full.txt

## Install

Direct: npm install @stackline/deepmerge

Drop-in alias: npm install deepmerge@npm:@stackline/deepmerge

## Core contract

- Default arrays concatenate.
- Inputs are not mutated.
- __proto__, prototype, and constructor are skipped by default at every depth.
- onUnsafeKey: "throw" rejects unsafe input.
- Cycles and shared references are preserved.
- maxDepth and maxKeys bound traversal.
- ESM, callable CommonJS, browser global, and TypeScript are supported.