---
title: Architecture
permalink: architecture
---

# Architecture

Tree-sitter consists of two separate libraries, both of which expose C APIs.

The first library, `libcompiler`, is
used to generate a parser for a language by supplying a [context-free grammar](https://en.wikipedia.org/wiki/Context-free_grammar) describing the
language. `libcompiler` is a build tool; it is no longer needed once a parser has been generated. Its public interface is specified in the header file [`compiler.h`](https://github.com/tree-sitter/tree-sitter/blob/master/include/tree_sitter/compiler.h).

The second library, `libruntime`, is used in combination with the parsers
generated by `libcompiler`, to produce syntax trees from source code and keep the
syntax trees up-to-date as the source code changes. `libruntime` is designed to be embedded in applications. Its interface is specified in the header file [`runtime.h`](https://github.com/tree-sitter/tree-sitter/blob/master/include/tree_sitter/runtime.h).

## The Compiler

WIP

## The Runtime

WIP