Neovim, Zed and Helix¶

inwards server is a language server over stdio, in the binary from Inwards 0.5.0 on. An editor with an LSP client starts it and shows, for every file in the workspace, what inwards check reports there: the file you type in is checked on every change, and the whole workspace again on every save. VS Code has an extension; this page sets up the editors that take a language server from their config.

The server only reports diagnostics. It has no completion, hover or code actions, so it runs next to your Python language server (ty, basedpyright, Ruff), not instead of it.

Before you start¶

• Install Inwards 0.5.0 or newer, and add [tool.inwards] to pyproject.toml. inwards --help lists inwards server when the binary has it.
• Each editor below starts the server in the project root, the directory that holds pyproject.toml. There it checks what inwards check run in that directory would check, with that directory's config (ADR-041).
• With Inwards as a uv dev dependency, start uv run inwards server instead of inwards server, so each project runs the version it pins. Each section shows where the command goes.

Neovim¶

Neovim 0.11 added vim.lsp.config and vim.lsp.enable, so no plugin is needed. Add to init.lua:

vim.lsp.config("inwards", {
  cmd = { "inwards", "server" },
  filetypes = { "python" },
  root_markers = { "pyproject.toml" },
})
vim.lsp.enable("inwards")

Neovim searches upwards from the Python file for pyproject.toml and uses that directory as the root. To keep the config in its own file instead, put the table in lsp/inwards.lua on your runtimepath (~/.config/nvim/lsp/inwards.lua) and keep only vim.lsp.enable("inwards") in init.lua:

return {
  cmd = { "inwards", "server" },
  filetypes = { "python" },
  root_markers = { "pyproject.toml" },
}

With uv, start the server in the project root. Neovim starts cmd in its own working directory, which isn't always the project, and uv run finds the project from the directory it runs in:

vim.lsp.config("inwards", {
  cmd = function(dispatchers, config)
    return vim.lsp.rpc.start({ "uv", "run", "inwards", "server" }, dispatchers, { cwd = config.root_dir })
  end,
  filetypes = { "python" },
  root_markers = { "pyproject.toml" },
})
vim.lsp.enable("inwards")

nvim-lspconfig has no config for Inwards, and none is needed: the snippets work with it installed. Its old require("lspconfig") setup is deprecated, so don't register Inwards through lspconfig.configs.

Check it works:

• Open a Python file in the project and run :checkhealth vim.lsp. inwards is listed among the active clients, with the project as its root.
• A layer violation shows as a diagnostic with source inwards and its rule code. :lua vim.diagnostic.setqflist() lists them all in the quickfix window.
• After changing the config, :lsp restart inwards (Neovim 0.12) restarts the server.

Zed¶

Zed starts only language servers that Zed itself or an extension registers; settings can't add a new one (zed#52653). Inwards has no extension in Zed's registry yet, so install this one as a dev extension. It is three files; Zed compiles the Rust to WebAssembly when it installs it, which needs Rust installed through rustup.

id = "inwards-local"
name = "Inwards (local)"
version = "0.1.0"
schema_version = 1
authors = ["You <you@example.com>"]
description = "Starts inwards server for Python files."
repository = "https://github.com/SirCypkowskyy/inwards"

[language_servers.inwards]
name = "Inwards"
languages = ["Python"]

[package]
name = "inwards_zed"
version = "0.1.0"
edition = "2021"

[lib]
path = "src/lib.rs"
crate-type = ["cdylib"]

[dependencies]
zed_extension_api = "0.7.0"

use zed_extension_api::{self as zed, settings::LspSettings, LanguageServerId, Result};

struct Inwards;

impl zed::Extension for Inwards {
    fn new() -> Self {
        Inwards
    }

    fn language_server_command(
        &mut self,
        server_id: &LanguageServerId,
        worktree: &zed::Worktree,
    ) -> Result<zed::Command> {
        let binary = LspSettings::for_worktree(server_id.as_ref(), worktree)
            .ok()
            .and_then(|settings| settings.binary);
        let args = binary
            .as_ref()
            .and_then(|b| b.arguments.clone())
            .unwrap_or_else(|| vec!["server".into()]);
        let command = binary
            .and_then(|b| b.path)
            .or_else(|| worktree.which("inwards"))
            .ok_or("inwards isn't on PATH; install it or set lsp.inwards.binary.path")?;
        Ok(zed::Command {
            command,
            args,
            env: worktree.shell_env(),
        })
    }
}

zed::register_extension!(Inwards);

Then, in Zed, run zed: install dev extension from the command palette and pick the inwards-zed directory. The extension looks for inwards on the PATH of the project's shell and starts inwards server in the worktree's root.

Zed's default for Python ends with "...", which takes in every registered server, so inwards runs next to basedpyright and Ruff with no more settings. If you set languages.Python.language_servers yourself, keep "..." in the list or name "inwards".

With uv, point the extension at uv in your settings. The lsp.inwards.binary entry replaces the command and its arguments:

{
  "lsp": {
    "inwards": {
      "binary": { "path": "uv", "arguments": ["run", "inwards", "server"] }
    }
  }
}

Check it works:

• The lightning-bolt icon in the status bar lists inwards among the running servers for a Python file. dev: open language server logs shows what it wrote to stderr.
• A layer violation shows in the editor and in the project diagnostics panel with its rule code.
• If the server doesn't start, zed: open log has the reason, such as the PATH message from the extension.

Helix¶

Add the server and the Python language list to languages.toml, in ~/.config/helix/ for every project or in the project's .helix/ for one:

[language-server.inwards]
command = "inwards"
args = ["server"]

[[language]]
name = "python"
language-servers = ["ty", "ruff", "jedi", "pylsp", "inwards"]

language-servers replaces Helix's default list instead of adding to it. The list above is Helix 25.07.1's default (ty, ruff, jedi, pylsp) with inwards added; drop the servers you don't use. Helix collects diagnostics from every server in the list, so the order doesn't matter for Inwards.

Helix starts the server in the project root, the nearest directory above the file with one of Python's root markers (pyproject.toml, setup.py, poetry.lock, pyrightconfig.json). With uv, that's where uv run finds the project:

[language-server.inwards]
command = "uv"
args = ["run", "inwards", "server"]

Check it works:

• hx --health python lists inwards among the language servers and says whether it found the binary.
• A layer violation shows in the gutter and in the diagnostics picker (Space d) with its rule code.
• :lsp-restart restarts the servers after a config change; :log-open shows why one didn't start.

Architecture diagrams¶

With INW017 or INW018 on, the server checks the Markdown, Mermaid and PlantUML files the diagrams key lists too: a closed one with each whole-project pass, an open one on every change, from the unsaved text. Saving a diagram runs no pass, since nothing else depends on it. Any other Markdown file is left alone. The editor has to send the server those files, so add their file types where you added python, as the VS Code extension does:

• Neovim: filetypes = { "python", "markdown", "mermaid", "plantuml" }.
• Zed: languages = ["Python", "Markdown"] in extension.toml.
• Helix: add inwards to the language-servers of the markdown language too.

These lines follow each editor's docs and haven't been tried by hand.

Troubleshooting¶