Adding languages

Adding new languages to Helix

In order to add a new language to Helix, you will need to follow the steps below.

Add a new [[language]] entry in the languages.toml file and provide the necessary configuration for the new language. For more information on language configuration, refer to the language configuration section of the documentation. A new language server can be added by extending the [language-server] table in the same file.
If you are adding a new language or updating an existing language server configuration, run the command cargo xtask docgen to update the Language Support documentation.

💡 If you are adding a new Language Server configuration, make sure to update the Language Server Wiki with the installation instructions.

If a tree-sitter grammar is available for the new language, add a new [[grammar]] entry to the languages.toml file.
If you are testing the grammar locally, you can use the source.path key with an absolute path to the grammar. However, before submitting a pull request, make sure to switch to using source.git.

In order to provide syntax highlighting and indentation for the new language, you will need to add queries.
Create a new directory for the language with the path runtime/queries/<name>/.
Refer to the tree-sitter website for more information on writing queries.
A list of highlight captures can be found on the themes page.

If you encounter errors when running Helix after switching branches, you may need to update the tree-sitter grammars. Run the command hx --grammar fetch to fetch the grammars and hx --grammar build to build any out-of-date grammars.
If a parser is causing a segfault, or you want to remove it, make sure to remove the compiled parser located at runtime/grammars/<name>.so.
If you are attempting to add queries and Helix is unable to locate them, ensure that the environment variable HELIX_RUNTIME is set to the location of the runtime folder you're developing in.