Helix 25.07 adds new file explorer and debuts tree-house for syntax layers

Helix 25.07 delivers notable changes with the replacement of Tree-sitter by the internally developed tree-house crate. This new engine, built from scratch, improves performance and maintainability while setting the stage for more consistent syntax features throughout the editor.

Tree-house supports intricate nested language injections. For example, users editing Markdown with embedded Rust code inside doc comments benefit from persistent locals highlighting, even when definitions scroll out of view. Its incremental injection handling ensures only modified syntax layers are re-parsed, optimizing responsiveness during work with large, complex documents. The new QueryIter API, introduced within tree-house, enables queries and operations across all syntax layers. This change lays the groundwork for advanced editing tooling—such as cross-language text object selection and precise indentation—across injected code.

In addition to these engine upgrades, a new file explorer can be opened with <space>e. This explorer offers fuzzy search and intuitive navigation through nested directories and files. Core improvements include a full rewrite of command mode, enabling more reliable argument parsing, improved file path completion (including paths with spaces), and support for command flags and expansion syntax. Helix also adds LSP document color support, displaying inline color swatches with compatible language servers. Parsing updates in scripting make configuration easier and shell command integration smoother.