@essence-lang/cli

essence — the command line for the Essence programming language. One binary carries the whole toolchain: the compiler, the formatter, the Language Server and the Debug Adapter.

Install

npm install -g @essence-lang/cli

This puts essence on PATH, along with esc, the same binary under its historic name. Node 22 or later runs it; under Bun it works the same.

Usage

essence <command> [file...] [options]
essence <file.es>              same as: essence build <file.es>

| Command | | | -------- | -------------------------------------------------------- | | build | Compile Essence sources to JavaScript (the default) | | run | Compile a source file and execute it immediately | | check | Type-check sources without writing any output | | watch | Recompile automatically whenever a source changes | | format | Format Essence sources in place | | lsp | Start the Essence Language Server, speaking over stdio | | dap | Start the Essence Debug Adapter, speaking over stdio | | help | Show help for essence or for a single command |

essence HelloWorld.es compiles one file to HelloWorld.js beside it. The emitted bundle is a self-contained ES module — the runtime is inlined and tree-shaken into it — and runs under Node or Bun with no dependencies. --sourcemap emits a source map whose positions are the .es lines the author wrote, which is what the debugger and mapped stack traces read.

essence --help documents every option; essence help <command> goes deeper on one. --json turns any build into a machine-readable report.