# Amber

> Amber is a free, open-source (MIT) JavaScript and TypeScript runtime built with Rust and V8. One `amber` binary runs scripts, Jest-style tests, bundling, single-file compile, a small package installer, an HTTP serve command, and an opt-in capability sandbox for agent tools. It is not a drop-in Node.js replacement: each API is labeled Stable, Preview, Experimental, or Not supported.

- Current release: v1.17.0. Install: `curl -fsSL https://get.amberjs.com/install.sh | sh` (macOS/Linux) or `irm https://get.amberjs.com/install.ps1 | iex` (Windows PowerShell). See [Installation](https://amberjs.com/docs/installation.md).
- License: MIT, free and open source. Source: https://github.com/zh30/amberjs
- Pricing: none. Amber is free to use; there is no paid tier, plan, or license fee.
- Status labels: Stable / Preview / Experimental / Not supported, from [docs/CURRENT_SCOPE.md](https://github.com/zh30/amberjs/blob/main/docs/CURRENT_SCOPE.md). 69 Stable contracts (G1–G69). Full table: [Compatibility](https://amberjs.com/compatibility.md).
- Node conformance scorecard: 56/56 PASS on main.
- Amber is not a drop-in replacement for Node.js, Bun, or Deno, and publishes no current performance numbers.

## Overview

- [Overview](https://amberjs.com/index.md): What Amber is and is not, install commands, license, and status summary
- [Compatibility & scope](https://amberjs.com/compatibility.md): Every Stable contract with limits, plus Preview, Experimental, and non-goals
- [Docs index](https://amberjs.com/docs.md): Table of contents for the manual

## Getting started

- [Introduction](https://amberjs.com/docs/introduction.md): Amber is a JavaScript and TypeScript runtime built with Rust and V8. This manual covers v1.17.0.
- [Installation](https://amberjs.com/docs/installation.md): Install the amber binary from a release archive, or build it from source with Cargo.
- [Quick start](https://amberjs.com/docs/quick-start.md): Run a script, a TypeScript file, a test, and an HTTP handler in a few minutes.

## Guides

- [CLI reference](https://amberjs.com/docs/cli-usage.md): Every amber subcommand in v1.17.0, grouped by maturity. Checked against src/main.rs.
- [TypeScript](https://amberjs.com/docs/typescript.md): Run .ts and .tsx files directly. Amber transpiles with oxc and does not type-check.
- [Test runner](https://amberjs.com/docs/testing.md): amber test discovers and runs Jest-style tests without extra dependencies.
- [Server mode](https://amberjs.com/docs/server-mode.md): Serve a fetch-style handler over HTTP/1.1, with optional rustls TLS.
- [Package installer](https://amberjs.com/docs/package-manager.md): Install direct dependencies from package.json, with lockfile pins and integrity checks. Not an npm replacement.
- [Bundle and compile](https://amberjs.com/docs/bundling-compilation.md): amber bundle packs a module graph into one file. amber compile turns it into a single executable for this host.
- [Debugging](https://amberjs.com/docs/debugging.md): A small Chrome DevTools Protocol endpoint for evaluating code in a running script.

## Compatibility

- [Stability levels](https://amberjs.com/docs/stability.md): How Amber decides what is Stable, Preview, Experimental, or not supported.
- [Node.js compatibility](https://amberjs.com/docs/node-compat.md): Which Node modules are Stable, what each contract covers, and what stays out.
- [Web APIs](https://amberjs.com/docs/web-apis.md): The Web-platform globals Amber pins with contracts, and the ones it deliberately leaves out.
- [WinterTC baseline](https://amberjs.com/docs/wintertc-compliance.md): ECMA-429 minimum common Web API, runtime keys, and the Sockets API.

## Agents & sandbox

- [Agent sandbox](https://amberjs.com/docs/agent-sandbox.md): Run tool code with file, network, environment, and process access denied unless you allow it.
- [Tools, sessions, and MCP](https://amberjs.com/docs/mcp-protocol.md): Export functions from a file, then call them through a JSON-RPC session or an MCP stdio server.
- [amber:ai](https://amberjs.com/docs/ai-engine.md): Typed-array tensors, a built-in text embedding, and an LLM interface for local model files.
- [WebAssembly](https://amberjs.com/docs/wasm-interop.md): Standard WebAssembly on V8, Stable streaming compilation, and the Preview amber:wasm zero-copy helpers.

## Optional

- [Experimental surfaces](https://amberjs.com/docs/experimental.md): Commands, flags, and modules that ship in the binary but are not product promises yet.
- [Full text of all pages](https://amberjs.com/llms-full.txt): Every Markdown page above, concatenated
- [Release notes](https://amberjs.com/blog): Blog posts (HTML). Older posts may quote historical benchmark numbers that are not current claims
- [Source code](https://github.com/zh30/amberjs): GitHub repository
- [CURRENT_SCOPE.md](https://github.com/zh30/amberjs/blob/main/docs/CURRENT_SCOPE.md): Authoritative capability boundary
- [Conformance scorecard](https://github.com/zh30/amberjs/blob/main/tests/conformance/scorecard.md): 56/56 Node conformance fixtures