diff --git a/files/autofmt.js b/files/autofmt.js
deleted file mode 100755
index 4e2ff72211661546099d762e33526cb0781cf8a9..0000000000000000000000000000000000000000
--- a/files/autofmt.js
+++ /dev/null
@@ -1,593 +0,0 @@
-#!/usr/bin/env node
-// autofmt v1 - https://paperclover.dev/nix/config/src/branch/main/files/autofmt.js
-//
-// Different codebases use different formatters. Autofmt looks for project
-// configuration to pick the correct formatter, allowing an editor to simply
-// point to this script and ambiguities resolved. This single file program
-// depends only on Node.js v22.
-//
-// When using this repository's Nix-based Neovim configuration, autofmt is
-// automatically configured as the default formatter. To configure manually,
-// set the editor's formatter to run `autofmt --stdio=<filename>`. The filename
-// is used to determine which formatter to invoke.
-//
-// With `conform.nvim`:
-//   formatters = {
-//     autofmt = { command = "autofmt" }
-//   }
-//
-// With Zed:
-//   "formatter": {
-//     "external": {
-//       "command": "autofmt",
-//       "arguments": ["--stdio", "{buffer_path}"]
-//     }
-//   },
-//
-// @ts-nocheck
-
-// -- definitions --
-const extensions = {
-  c: [".c", ".h"],
-  cpp: [".cpp", ".cc", ".cxx", ".hpp", ".hxx", ".hh"],
-  css: [".css"],
-  html: [".html"],
-  javascript: [".js", ".ts", ".cjs", ".cts", ".mjs", ".mts", ".jsx", ".tsx"],
-  json: [".json", ".jsonc"],
-  markdown: [".md", ".markdown"],
-  mdx: [".mdx"],
-  nix: [".nix"],
-  rust: [".rs"],
-  toml: [".toml"],
-  yaml: [".yml", ".yaml"],
-  zig: [".zig"],
-};
-const formatters = {
-  // this object is sorted by priority
-  //
-  // `languages: true` are multiplexers that apply to all listed
-  // languages, as it is assumed a project will setup their multiplexer
-  // correctly for all tracked files.
-  //
-  // if a formatter doesnt match a config file, the first one is picked
-  // as a default, making things like `deno fmt file.ts` or `clang-format`
-  // the default when there are no config files.
-  dprint: {
-    languages: true,
-    files: ["dprint.json", "dprint.jsonc"],
-    cmd: ["dprint", "fmt", "--", "$files"],
-    stdin: (file) => ["dprint", "fmt", "--stdin", file],
-  },
-  treefmt: {
-    languages: true,
-    files: ["treefmt.toml", ".treefmt.toml"],
-    cmd: ["treefmt", "--", "$files"],
-    stdin: (file) => ["treefmt", "--stdin", file],
-  },
-  // -- web ecosystem --
-  deno: {
-    languages: ["javascript", "markdown", "json", "yaml", "html", "css"],
-    files: ["dprint.json", "dprint.jsonc"],
-    cmd: ["deno", "fmt", "--", "$files"],
-    stdin: (file) => ["deno", "fmt", "--ext", path.extname(file).slice(1), "-"],
-  },
-  prettier: {
-    languages: ["javascript", "markdown", "json", "yaml", "mdx", "html", "css"],
-    files: ["node_modules/.bin/prettier"],
-    cmd: ["node_modules/.bin/prettier", "--write", "--", "$files"],
-    stdin: (file) => ["node_modules/.bin/prettier", "--stdin-filepath", file],
-  },
-  biome: {
-    languages: ["javascript", "json", "css"],
-    files: ["node_modules/.bin/biome"],
-    cmd: ["node_modules/.bin/biome", "format", "--", "$files"],
-    stdin: (file) => [
-      "node_modules/bin/biome",
-      "format",
-      `--stdin-file-path=${file}`,
-    ],
-  },
-  "nixfmt-rfc-style": {
-    languages: ["nix"],
-    files: {
-      "flake.nix": (contents) => contents.includes("nixfmt"),
-    },
-    cmd: ["nixfmt", "--", "$files"],
-    stdin: (file) => ["nixfmt", `--filename=${file}`],
-  },
-  alejandra: {
-    languages: ["nix"],
-    files: {
-      "flake.nix": (contents) => contents.includes("alejandra"),
-    },
-    cmd: ["alejandra", "--", "$files"],
-    stdin: () => ["alejandra"],
-  },
-  clang: {
-    languages: ["c", "cpp"],
-    files: true,
-    cmd: ["clang-format", "--", "$files"],
-    stdin: (file) => ["clang-format", `--assume-filename=${file}`],
-  },
-  zig: {
-    languages: ["zig"],
-    files: true,
-    cmd: ["zig", "fmt", "$files"],
-    stdin: (file) => [
-      "zig",
-      "fmt",
-      "--stdin",
-      ...file.endsWith(".zon") ? ["--zon"] : [],
-    ],
-  },
-  rustfmt: {
-    languages: ["rust"],
-    files: true,
-    cmd: ["rustfmt", "--", "$files"],
-    stdin: () => ["rustfmt"],
-  },
-  taplo: {
-    languages: ["toml"],
-    files: ["taplo.toml"],
-    cmd: ["taplo", "format", "--", "$files"],
-    cmd: () => ["taplo", "format", "-"],
-  },
-};
-
-// -- cli --
-if (!fs.globSync) {
-  console.error(`error: autofmt must be run with Node.js v22 or newer`);
-  process.exit(1);
-}
-const [, bin, ...argv] = process.argv;
-let inputs = [];
-let globalExclude = [];
-let gitignore = true;
-let dryRun = false;
-let stdio = null;
-let excludes = [".git"];
-while (argv.length > 0) {
-  const arg = argv.shift();
-  if (arg === "-h" || arg === "--help") usage();
-  else if (arg === "--no-gitignore") gitignore = false;
-  else if (arg === "--dry-run") dryRun = true;
-  else if (arg.match(/^--stdio=./)) {
-    if (stdio) {
-      console.error("error: can only pass --stdio once");
-      usage();
-    }
-    stdio = arg.slice("--stdio=".length);
-  } else if (arg === "--stdio") {
-    const value = argv.shift();
-    if (!value) {
-      console.error("error: missing value for --stdio");
-      usage();
-    }
-    if (stdio) {
-      console.error("error: can only pass --stdio once");
-      usage();
-    }
-    stdio = value;
-  } else if (arg.match(/^--exclude=./)) {
-    excludes.push(arg.slice("--exclude=".length));
-  } else if (arg === "--") {
-    inputs.push(...argv);
-    break;
-  } else if (arg.startsWith("-")) {
-    console.error("error: unknown option " + JSON.stringify(arg));
-    usage();
-  } else inputs.push(arg);
-}
-function usage() {
-  const exe = path.basename(bin);
-  console.error(`usage: ${exe} [...files or directories]`);
-  console.error(``);
-  console.error(`uses the right formatter for the job (by scanning config)`);
-  console.error(`when autofmt reads dirs, it will respect gitignore`);
-  console.error(``);
-  console.error(`to format current directory recursively, run '${exe} .'`);
-  console.error(``);
-  console.error(`options:`);
-  console.error(`  --dry-run           print commands instead of running them`);
-  console.error(`  --no-gitignore      do not read '.gitignore'`);
-  console.error(`  --exclude=<glob>    add an exclusion glob`);
-  console.error(`  --stdio=<filename>  read/write contents via stdin/stdout`);
-  console.error(``);
-  process.exit(1);
-}
-if (inputs.length === 0 && !stdio) usage();
-if (stdio && inputs.length > 0) {
-  console.error("error: stdio mode only operates on one file");
-  process.exit(1);
-}
-const { sep } = path;
-
-// -- disable warnings --
-const { emit: originalEmit } = process;
-const warnings = ["ExperimentalWarning"];
-process.emit = function (event, error) {
-  return event === "warning" && warnings.includes(error.name)
-    ? false
-    : originalEmit.apply(process, arguments);
-};
-
-// -- vars --
-const extToLanguage = Object.fromEntries(
-  Object.entries(extensions).flatMap(([lang, exts]) =>
-    exts.map((ext) => [ext, lang])
-  ),
-);
-const multis = Object.keys(formatters).filter(
-  (x) => formatters[x].languages === true,
-);
-const files = [];
-const gitignores = new Map();
-const dirs = new Map();
-const cached = new Map();
-
-// -- stdin mode --
-if (stdio) {
-  const fmtWithPath = pickFormatter(stdio);
-  if (!fmtWithPath) {
-    console.error(`No formatter configured for ${path.relative(".", stdio)}`);
-    process.exit(1);
-  }
-  let [fmt, cwd] = fmtWithPath.split("\0");
-  let cmd = formatters[fmt].stdin(stdio);
-  cwd ??= process.cwd();
-  if (dryRun) {
-    console.info(cmd.join(" "));
-    process.exit(0);
-  }
-  const proc = child_process.spawn(cmd[0], cmd.slice(1), {
-    stdio: ["inherit", "inherit", "inherit"],
-  });
-  proc.on("error", (e) => {
-    let message = "";
-    if (e?.code === "ENOENT") {
-      message = `${cmd[0]} is not installed`;
-    } else {
-      message = String(e?.message ?? e);
-    }
-    console.error(`error: ${message}`);
-    process.exit(1);
-  });
-  const [code] = await events.once(proc, "exit");
-  process.exit(code ?? 1);
-}
-
-// -- decide what formatters to run
-inputs = inputs.map((x) => path.resolve(x));
-inputs.forEach(walk);
-const toRun = new Map();
-for (const file of new Set(files)) {
-  const fmt = pickFormatter(file);
-  if (!fmt) {
-    if (inputs.includes(file)) {
-      console.warn(`No formatter configured for ${path.relative(".", file)}`);
-    }
-    continue;
-  }
-  let list = toRun.get(fmt);
-  list ?? toRun.set(fmt, list = []);
-  list.push(file);
-}
-
-// -- create a list of commands --
-const commands = [];
-let totalFiles = 0;
-for (const [fmtWithPath, files] of toRun) {
-  let [fmt, cwd] = fmtWithPath.split("\0");
-  let { cmd } = formatters[fmt];
-  if (cwd) cmd = [path.join(cwd, cmd[0]), ...cmd.slice(1)];
-  cwd ??= process.cwd();
-  let i = 0;
-  totalFiles += files.length;
-  if ((i = cmd.indexOf("$files")) != -1) {
-    const c = cmd.slice();
-    c.splice(i, 1, ...files);
-    commands.push({ cmd: c, cwd, files });
-  } else if ((i = cmd.indexOf("$file")) != -1) {
-    for (const file of files) {
-      const c = cmd.slice();
-      c.splice(i, 1, file);
-      commands.push({ cmd: c, cwd, files: [file] });
-    }
-  } else {
-    throw new Error(`Formatter ${fmt} has incorrectly configured command.`);
-  }
-}
-if (commands.length === 0) {
-  console.error("No formattable files");
-  process.exit(0);
-}
-
-// -- dry run mode --
-if (dryRun) {
-  for (const { cmd } of commands) {
-    console.info(cmd);
-  }
-  process.exit(0);
-}
-
-// -- user interface --
-let filesComplete = 0;
-let lastFile = commands[0].cmd;
-const syncStart = "\u001B[?2026h";
-const syncEnd = "\u001B[?2026l";
-let buffer = "";
-let statusVisible = false;
-const tty = process.stderr.isTTY;
-function writeStatus() {
-  if (!tty) return;
-  clearStatus();
-  buffer ||= syncStart;
-  buffer += `${filesComplete}/${totalFiles} - ${lastFile}`;
-  statusVisible = true;
-}
-function clearStatus() {
-  if (!tty) return;
-  if (!statusVisible) return;
-  buffer ||= syncStart;
-  buffer += "\r\x1b[2K\r";
-  statusVisible = false;
-}
-function flush() {
-  if (!buffer) return;
-  const width = Math.max(1, process.stderr.columns - 1);
-  process.stderr.write(
-    buffer.split("\n").map((x) => x.slice(0, width)).join("\n") + syncEnd,
-  );
-  buffer = "";
-}
-
-// -- async process queue --
-let running = 0;
-/** @param cmd {{ cmd: string, cwd: string, files: string[] }} */
-function run({ cmd, cwd, files }) {
-  running += 1;
-  let c = child_process.spawn(cmd[0], cmd.slice(1), {
-    stdio: ["ignore", "pipe", "pipe"],
-    cwd,
-  });
-  const relatives = new Set(
-    files.map((file) => file.startsWith(cwd) ? path.relative(cwd, file) : file),
-  );
-  function onLine(line) {
-    for (const file of relatives) {
-      if (line.includes(file)) {
-        filesComplete += 1;
-        relatives.delete(file);
-        lastFile = path.relative(process.cwd(), path.resolve(cwd, file));
-        if (tty) {
-          writeStatus();
-          flush();
-        } else {
-          console.info(lastFile);
-        }
-        return;
-      }
-    }
-  }
-  let errBuffer = "";
-  let exited = false;
-  c.on("error", (e) => {
-    let message = "";
-    if (e?.code === "ENOENT") {
-      if (cmd[0].includes("/")) {
-        running -= 1;
-        run({ cmd: [path.basename(cmd[0]), ...cmd.slice(1)], cwd, files });
-        return;
-      }
-      message = `${cmd[0]} is not installed`;
-    } else {
-      message = String(e?.message ?? e);
-    }
-    clearStatus();
-    const filesConcise =
-      path.relative(".", path.resolve(cwd, relatives.keys().next().value)) + (
-        relatives.size > 1 ? ` and ${relatives.size - 1} more` : ""
-      );
-    buffer += errBuffer + `error: ${message}, cannot format ${filesConcise}.\n`;
-    flush();
-    exited = true;
-    runNext();
-  });
-  readline.createInterface(c.stderr).addListener("line", (line) => {
-    errBuffer += line + "\n";
-    onLine(line);
-  });
-  readline.createInterface(c.stdout).addListener("line", onLine);
-  c.on("exit", (code, signal) => {
-    if (exited) return;
-    exited = true;
-    if (code !== 0) {
-      clearStatus();
-      const exitStatus = code != null ? `code ${code}` : `signal ${signal}`;
-      buffer += errBuffer + `error: ${cmd[0]} exited with ${exitStatus}\n`;
-      flush();
-    } else {
-      filesComplete += relatives.size;
-      if (relatives.size) {
-        lastFile = path.relative(
-          ".",
-          path.resolve(cwd, relatives.keys().next().value),
-        );
-      }
-      writeStatus();
-      flush();
-    }
-    runNext();
-  });
-  function runNext() {
-    running -= 1;
-    const next = commands.pop();
-    if (next) run(next);
-    else if (running == 0) {
-      clearStatus();
-      flush();
-      console.info(
-        `Formatted ${filesComplete} file${filesComplete !== 1 ? "s" : ""}`,
-      );
-    }
-  }
-}
-
-for (let i = 0; i < navigator.hardwareConcurrency; i++) {
-  const cmd = commands.pop();
-  if (cmd) run(cmd);
-  else break;
-}
-
-// -- library functions --
-
-/** @param file {string} */
-function walk(file) {
-  file = path.resolve(file);
-  try {
-    if (fs.statSync(file).isDirectory()) {
-      const exclude = getGitIgnores(file);
-      const read = fs
-        .globSync(escapeGlob(file) + "/{**,.**}", {
-          exclude,
-          withFileTypes: true,
-        })
-        .filter((file) => !file.isDirectory())
-        .map((file) => path.join(file.parentPath, file.name));
-      files.push(...read);
-    } else {
-      files.push(file);
-    }
-  } catch (err) {
-    console.error(
-      `Failed to stat ${file}: ${err?.code ?? err?.message ?? err}`,
-    );
-    process.exit(1);
-  }
-}
-
-/** @param dir {string} @returns {Array<string>} */
-function readDir(dir) {
-  dir = path.resolve(dir);
-  let contents = dirs.get(dir);
-  if (!contents) {
-    try {
-      contents = fs.readdirSync(dir);
-    } catch {
-      contents = [];
-    }
-    dirs.set(dir, contents);
-  }
-  return contents;
-}
-
-/** @param dir {string} @returns {string} */
-function pickFormatter(file) {
-  const lang = extToLanguage[path.extname(file)];
-  const dir = path.dirname(file);
-  let c = walkUp(dir, (x) => cached.get(x) ?? cached.get(`${x}:${lang}`));
-  if (c) return c;
-
-  const possible = Object.keys(formatters).filter(
-    (x) =>
-      Array.isArray(formatters[x].languages) &&
-      formatters[x].languages.includes(lang),
-  );
-  const order = [...multis, ...possible];
-  return walkUp(dir, (x) => {
-    const children = readDir(x);
-    for (const fmt of order) {
-      let matches = false;
-      if (formatters[fmt].files === true) {
-        matches = true;
-      }
-      if (!matches) {
-        const filesToCheck = Array.isArray(formatters[fmt].files)
-          ? formatters[fmt].files.map((base) => ({ base, contents: true }))
-          : Object.entries(formatters[fmt].files)
-            .map(([base, contents]) => ({ base, contents }));
-        for (const { base, contents } of filesToCheck) {
-          if (base.includes("/")) {
-            matches = readDir(path.join(x, path.dirname(base))) //
-              .includes(path.basename(base));
-          } else {
-            matches = children.includes(base);
-          }
-          if (matches && typeof contents === "function") {
-            matches = !!contents(fs.readFileSync(path.join(x, base), "utf-8"));
-          }
-        }
-      }
-      if (matches) {
-        const formatterId = `${fmt}\0${x}`;
-        const k = multis.includes(fmt) ? x : `${x}:${lang}`;
-        cached.set(k, formatterId);
-        return formatterId;
-      }
-    }
-  }) ?? possible[0];
-}
-
-/** @param dir {string} @param find {(x: string) => any} */
-function walkUp(dir, find) {
-  do {
-    const found = find(dir);
-    if (found != null) return found;
-    const parent = path.dirname(dir);
-    if (parent === dir) break;
-    dir = parent;
-  } while (true);
-  return null;
-}
-
-/** @param dir {string} */
-function getGitIgnores(dir) {
-  if (!gitignore) return [];
-  if (dir.endsWith(sep)) dir = dir.slice(0, -1);
-  const files = fs.globSync(`${dir}${sep}{**${sep}*${sep},}.gitignore`, {});
-  const referenced = [];
-  for (const abs of files) {
-    const dir = path.dirname(abs);
-    referenced.push(dir);
-    if (!gitignores.has(dir)) gitignores.set(dir, readGitIgnore(dir));
-  }
-  do {
-    const parent = path.dirname(dir);
-    if (parent === dir || fs.existsSync(path.join(dir, ".git"))) break;
-    referenced.push(parent);
-    if (!gitignores.has(parent)) gitignores.set(parent, readGitIgnore(parent));
-    dir = parent;
-  } while (true);
-  return referenced.flatMap((root) =>
-    (gitignores.get(root) ?? [])
-      .filter((x) => x[0] !== "!")
-      .map(
-        (rule) => `${root}${sep}${rule[0] === "/" ? "" : `**${sep}`}${rule}`,
-      )
-  );
-}
-
-/** @param dir {string} */
-function readGitIgnore(dir) {
-  try {
-    return fs
-      .readFileSync(`${dir}${sep}.gitignore`, "utf-8")
-      .split("\n")
-      .map((line) => line.replace(/#.*$/, "").trim())
-      .filter(Boolean);
-  } catch {
-    return [];
-  }
-}
-
-function escapeGlob(str) {
-  return str.replace(/[\\*,{}]/g, "\\$&");
-}
-
-import * as child_process from "node:child_process";
-import * as fs from "node:fs";
-import * as path from "node:path";
-import * as readline from "node:readline";
-import * as events from "node:events";
-import process from "node:process";
-import assert from "node:assert";
diff --git a/flake.nix b/flake.nix
index 24e6c7d79ea873ac00f2801c9d9e13a37620da4a..72d7e578f967a98211741e1bb0bdb35eab8fef16 100644
--- a/flake.nix
+++ b/flake.nix
@@ -69,7 +69,7 @@
 
         # custom packages
         (_: pkgs: {
-          autofmt = pkgs.callPackage ./packages/autofmt.nix { };
+          autofmt = pkgs.callPackage ./packages/autofmt { };
         })
       ];
 
diff --git a/packages/autofmt.nix b/packages/autofmt.nix
deleted file mode 100644
index 16ade370450c4f4eb38f940ec30def0cec0241ee..0000000000000000000000000000000000000000
--- a/packages/autofmt.nix
+++ /dev/null
@@ -1,14 +0,0 @@
-{ pkgs, ... }:
-pkgs.writeShellApplication {
-  name = "autofmt";
-  runtimeInputs = with pkgs; [
-    # include only a couple of formatters by default
-    deno
-    nixfmt-rfc-style
-    dprint
-    rustfmt
-    zig
-    clang-tools
-  ];
-  text = ''exec deno run -A ${../files/autofmt.js} "$@"'';
-}
diff --git a/packages/autofmt/autofmt.js b/packages/autofmt/autofmt.js
new file mode 100755
index 0000000000000000000000000000000000000000..dc8481d663f42c7849af589caaf249260b63e4b6
--- /dev/null
+++ b/packages/autofmt/autofmt.js
@@ -0,0 +1,594 @@
+#!/usr/bin/env node
+// autofmt v1 by paper clover
+// https://paperclover.dev/nix/config/src/branch/main/packages/autofmt/autofmt.js
+//
+// Different codebases use different formatters. Autofmt looks for project
+// configuration to pick the correct formatter, allowing an editor to simply
+// point to this script and ambiguities resolved. This single file program
+// depends only on Node.js v22.
+//
+// When using this repository's Nix-based Neovim configuration, autofmt is
+// automatically configured as the default formatter. To configure manually,
+// set the editor's formatter to run `autofmt --stdio=<filename>`. The filename
+// is used to determine which formatter to invoke.
+//
+// With `conform.nvim`:
+//   formatters = {
+//     autofmt = { command = "autofmt" }
+//   }
+//
+// With Zed:
+//   "formatter": {
+//     "external": {
+//       "command": "autofmt",
+//       "arguments": ["--stdio", "{buffer_path}"]
+//     }
+//   },
+//
+// @ts-nocheck
+
+// -- definitions --
+const extensions = {
+  c: [".c", ".h"],
+  cpp: [".cpp", ".cc", ".cxx", ".hpp", ".hxx", ".hh"],
+  css: [".css"],
+  html: [".html"],
+  javascript: [".js", ".ts", ".cjs", ".cts", ".mjs", ".mts", ".jsx", ".tsx"],
+  json: [".json", ".jsonc"],
+  markdown: [".md", ".markdown"],
+  mdx: [".mdx"],
+  nix: [".nix"],
+  rust: [".rs"],
+  toml: [".toml"],
+  yaml: [".yml", ".yaml"],
+  zig: [".zig"],
+};
+const formatters = {
+  // this object is sorted by priority
+  //
+  // `languages: true` are multiplexers that apply to all listed
+  // languages, as it is assumed a project will setup their multiplexer
+  // correctly for all tracked files.
+  //
+  // if a formatter doesnt match a config file, the first one is picked
+  // as a default, making things like `deno fmt file.ts` or `clang-format`
+  // the default when there are no config files.
+  dprint: {
+    languages: true,
+    files: ["dprint.json", "dprint.jsonc"],
+    cmd: ["dprint", "fmt", "--", "$files"],
+    stdin: (file) => ["dprint", "fmt", "--stdin", file],
+  },
+  treefmt: {
+    languages: true,
+    files: ["treefmt.toml", ".treefmt.toml"],
+    cmd: ["treefmt", "--", "$files"],
+    stdin: (file) => ["treefmt", "--stdin", file],
+  },
+  // -- web ecosystem --
+  deno: {
+    languages: ["javascript", "markdown", "json", "yaml", "html", "css"],
+    files: ["dprint.json", "dprint.jsonc"],
+    cmd: ["deno", "fmt", "--", "$files"],
+    stdin: (file) => ["deno", "fmt", "--ext", path.extname(file).slice(1), "-"],
+  },
+  prettier: {
+    languages: ["javascript", "markdown", "json", "yaml", "mdx", "html", "css"],
+    files: ["node_modules/.bin/prettier"],
+    cmd: ["node_modules/.bin/prettier", "--write", "--", "$files"],
+    stdin: (file) => ["node_modules/.bin/prettier", "--stdin-filepath", file],
+  },
+  biome: {
+    languages: ["javascript", "json", "css"],
+    files: ["node_modules/.bin/biome"],
+    cmd: ["node_modules/.bin/biome", "format", "--", "$files"],
+    stdin: (file) => [
+      "node_modules/bin/biome",
+      "format",
+      `--stdin-file-path=${file}`,
+    ],
+  },
+  "nixfmt-rfc-style": {
+    languages: ["nix"],
+    files: {
+      "flake.nix": (contents) => contents.includes("nixfmt"),
+    },
+    cmd: ["nixfmt", "--", "$files"],
+    stdin: (file) => ["nixfmt", `--filename=${file}`],
+  },
+  alejandra: {
+    languages: ["nix"],
+    files: {
+      "flake.nix": (contents) => contents.includes("alejandra"),
+    },
+    cmd: ["alejandra", "--", "$files"],
+    stdin: () => ["alejandra"],
+  },
+  clang: {
+    languages: ["c", "cpp"],
+    files: true,
+    cmd: ["clang-format", "--", "$files"],
+    stdin: (file) => ["clang-format", `--assume-filename=${file}`],
+  },
+  zig: {
+    languages: ["zig"],
+    files: true,
+    cmd: ["zig", "fmt", "$files"],
+    stdin: (file) => [
+      "zig",
+      "fmt",
+      "--stdin",
+      ...file.endsWith(".zon") ? ["--zon"] : [],
+    ],
+  },
+  rustfmt: {
+    languages: ["rust"],
+    files: true,
+    cmd: ["rustfmt", "--", "$files"],
+    stdin: () => ["rustfmt"],
+  },
+  taplo: {
+    languages: ["toml"],
+    files: ["taplo.toml"],
+    cmd: ["taplo", "format", "--", "$files"],
+    cmd: () => ["taplo", "format", "-"],
+  },
+};
+
+// -- cli --
+if (!fs.globSync) {
+  console.error(`error: autofmt must be run with Node.js v22 or newer`);
+  process.exit(1);
+}
+const [, bin, ...argv] = process.argv;
+let inputs = [];
+let globalExclude = [];
+let gitignore = true;
+let dryRun = false;
+let stdio = null;
+let excludes = [".git"];
+while (argv.length > 0) {
+  const arg = argv.shift();
+  if (arg === "-h" || arg === "--help") usage();
+  else if (arg === "--no-gitignore") gitignore = false;
+  else if (arg === "--dry-run") dryRun = true;
+  else if (arg.match(/^--stdio=./)) {
+    if (stdio) {
+      console.error("error: can only pass --stdio once");
+      usage();
+    }
+    stdio = arg.slice("--stdio=".length);
+  } else if (arg === "--stdio") {
+    const value = argv.shift();
+    if (!value) {
+      console.error("error: missing value for --stdio");
+      usage();
+    }
+    if (stdio) {
+      console.error("error: can only pass --stdio once");
+      usage();
+    }
+    stdio = value;
+  } else if (arg.match(/^--exclude=./)) {
+    excludes.push(arg.slice("--exclude=".length));
+  } else if (arg === "--") {
+    inputs.push(...argv);
+    break;
+  } else if (arg.startsWith("-")) {
+    console.error("error: unknown option " + JSON.stringify(arg));
+    usage();
+  } else inputs.push(arg);
+}
+function usage() {
+  const exe = path.basename(bin);
+  console.error(`usage: ${exe} [...files or directories]`);
+  console.error(``);
+  console.error(`uses the right formatter for the job (by scanning config)`);
+  console.error(`when autofmt reads dirs, it will respect gitignore`);
+  console.error(``);
+  console.error(`to format current directory recursively, run '${exe} .'`);
+  console.error(``);
+  console.error(`options:`);
+  console.error(`  --dry-run           print commands instead of running them`);
+  console.error(`  --no-gitignore      do not read '.gitignore'`);
+  console.error(`  --exclude=<glob>    add an exclusion glob`);
+  console.error(`  --stdio=<filename>  read/write contents via stdin/stdout`);
+  console.error(``);
+  process.exit(1);
+}
+if (inputs.length === 0 && !stdio) usage();
+if (stdio && inputs.length > 0) {
+  console.error("error: stdio mode only operates on one file");
+  process.exit(1);
+}
+const { sep } = path;
+
+// -- disable warnings --
+const { emit: originalEmit } = process;
+const warnings = ["ExperimentalWarning"];
+process.emit = function (event, error) {
+  return event === "warning" && warnings.includes(error.name)
+    ? false
+    : originalEmit.apply(process, arguments);
+};
+
+// -- vars --
+const extToLanguage = Object.fromEntries(
+  Object.entries(extensions).flatMap(([lang, exts]) =>
+    exts.map((ext) => [ext, lang])
+  ),
+);
+const multis = Object.keys(formatters).filter(
+  (x) => formatters[x].languages === true,
+);
+const files = [];
+const gitignores = new Map();
+const dirs = new Map();
+const cached = new Map();
+
+// -- stdin mode --
+if (stdio) {
+  const fmtWithPath = pickFormatter(stdio);
+  if (!fmtWithPath) {
+    console.error(`No formatter configured for ${path.relative(".", stdio)}`);
+    process.exit(1);
+  }
+  let [fmt, cwd] = fmtWithPath.split("\0");
+  let cmd = formatters[fmt].stdin(stdio);
+  cwd ??= process.cwd();
+  if (dryRun) {
+    console.info(cmd.join(" "));
+    process.exit(0);
+  }
+  const proc = child_process.spawn(cmd[0], cmd.slice(1), {
+    stdio: ["inherit", "inherit", "inherit"],
+  });
+  proc.on("error", (e) => {
+    let message = "";
+    if (e?.code === "ENOENT") {
+      message = `${cmd[0]} is not installed`;
+    } else {
+      message = String(e?.message ?? e);
+    }
+    console.error(`error: ${message}`);
+    process.exit(1);
+  });
+  const [code] = await events.once(proc, "exit");
+  process.exit(code ?? 1);
+}
+
+// -- decide what formatters to run
+inputs = inputs.map((x) => path.resolve(x));
+inputs.forEach(walk);
+const toRun = new Map();
+for (const file of new Set(files)) {
+  const fmt = pickFormatter(file);
+  if (!fmt) {
+    if (inputs.includes(file)) {
+      console.warn(`No formatter configured for ${path.relative(".", file)}`);
+    }
+    continue;
+  }
+  let list = toRun.get(fmt);
+  list ?? toRun.set(fmt, list = []);
+  list.push(file);
+}
+
+// -- create a list of commands --
+const commands = [];
+let totalFiles = 0;
+for (const [fmtWithPath, files] of toRun) {
+  let [fmt, cwd] = fmtWithPath.split("\0");
+  let { cmd } = formatters[fmt];
+  if (cwd) cmd = [path.join(cwd, cmd[0]), ...cmd.slice(1)];
+  cwd ??= process.cwd();
+  let i = 0;
+  totalFiles += files.length;
+  if ((i = cmd.indexOf("$files")) != -1) {
+    const c = cmd.slice();
+    c.splice(i, 1, ...files);
+    commands.push({ cmd: c, cwd, files });
+  } else if ((i = cmd.indexOf("$file")) != -1) {
+    for (const file of files) {
+      const c = cmd.slice();
+      c.splice(i, 1, file);
+      commands.push({ cmd: c, cwd, files: [file] });
+    }
+  } else {
+    throw new Error(`Formatter ${fmt} has incorrectly configured command.`);
+  }
+}
+if (commands.length === 0) {
+  console.error("No formattable files");
+  process.exit(0);
+}
+
+// -- dry run mode --
+if (dryRun) {
+  for (const { cmd } of commands) {
+    console.info(cmd);
+  }
+  process.exit(0);
+}
+
+// -- user interface --
+let filesComplete = 0;
+let lastFile = commands[0].cmd;
+const syncStart = "\u001B[?2026h";
+const syncEnd = "\u001B[?2026l";
+let buffer = "";
+let statusVisible = false;
+const tty = process.stderr.isTTY;
+function writeStatus() {
+  if (!tty) return;
+  clearStatus();
+  buffer ||= syncStart;
+  buffer += `${filesComplete}/${totalFiles} - ${lastFile}`;
+  statusVisible = true;
+}
+function clearStatus() {
+  if (!tty) return;
+  if (!statusVisible) return;
+  buffer ||= syncStart;
+  buffer += "\r\x1b[2K\r";
+  statusVisible = false;
+}
+function flush() {
+  if (!buffer) return;
+  const width = Math.max(1, process.stderr.columns - 1);
+  process.stderr.write(
+    buffer.split("\n").map((x) => x.slice(0, width)).join("\n") + syncEnd,
+  );
+  buffer = "";
+}
+
+// -- async process queue --
+let running = 0;
+/** @param cmd {{ cmd: string, cwd: string, files: string[] }} */
+function run({ cmd, cwd, files }) {
+  running += 1;
+  let c = child_process.spawn(cmd[0], cmd.slice(1), {
+    stdio: ["ignore", "pipe", "pipe"],
+    cwd,
+  });
+  const relatives = new Set(
+    files.map((file) => file.startsWith(cwd) ? path.relative(cwd, file) : file),
+  );
+  function onLine(line) {
+    for (const file of relatives) {
+      if (line.includes(file)) {
+        filesComplete += 1;
+        relatives.delete(file);
+        lastFile = path.relative(process.cwd(), path.resolve(cwd, file));
+        if (tty) {
+          writeStatus();
+          flush();
+        } else {
+          console.info(lastFile);
+        }
+        return;
+      }
+    }
+  }
+  let errBuffer = "";
+  let exited = false;
+  c.on("error", (e) => {
+    let message = "";
+    if (e?.code === "ENOENT") {
+      if (cmd[0].includes("/")) {
+        running -= 1;
+        run({ cmd: [path.basename(cmd[0]), ...cmd.slice(1)], cwd, files });
+        return;
+      }
+      message = `${cmd[0]} is not installed`;
+    } else {
+      message = String(e?.message ?? e);
+    }
+    clearStatus();
+    const filesConcise =
+      path.relative(".", path.resolve(cwd, relatives.keys().next().value)) + (
+        relatives.size > 1 ? ` and ${relatives.size - 1} more` : ""
+      );
+    buffer += errBuffer + `error: ${message}, cannot format ${filesConcise}.\n`;
+    flush();
+    exited = true;
+    runNext();
+  });
+  readline.createInterface(c.stderr).addListener("line", (line) => {
+    errBuffer += line + "\n";
+    onLine(line);
+  });
+  readline.createInterface(c.stdout).addListener("line", onLine);
+  c.on("exit", (code, signal) => {
+    if (exited) return;
+    exited = true;
+    if (code !== 0) {
+      clearStatus();
+      const exitStatus = code != null ? `code ${code}` : `signal ${signal}`;
+      buffer += errBuffer + `error: ${cmd[0]} exited with ${exitStatus}\n`;
+      flush();
+    } else {
+      filesComplete += relatives.size;
+      if (relatives.size) {
+        lastFile = path.relative(
+          ".",
+          path.resolve(cwd, relatives.keys().next().value),
+        );
+      }
+      writeStatus();
+      flush();
+    }
+    runNext();
+  });
+  function runNext() {
+    running -= 1;
+    const next = commands.pop();
+    if (next) run(next);
+    else if (running == 0) {
+      clearStatus();
+      flush();
+      console.info(
+        `Formatted ${filesComplete} file${filesComplete !== 1 ? "s" : ""}`,
+      );
+    }
+  }
+}
+
+for (let i = 0; i < navigator.hardwareConcurrency; i++) {
+  const cmd = commands.pop();
+  if (cmd) run(cmd);
+  else break;
+}
+
+// -- library functions --
+
+/** @param file {string} */
+function walk(file) {
+  file = path.resolve(file);
+  try {
+    if (fs.statSync(file).isDirectory()) {
+      const exclude = getGitIgnores(file);
+      const read = fs
+        .globSync(escapeGlob(file) + "/{**,.**}", {
+          exclude,
+          withFileTypes: true,
+        })
+        .filter((file) => !file.isDirectory())
+        .map((file) => path.join(file.parentPath, file.name));
+      files.push(...read);
+    } else {
+      files.push(file);
+    }
+  } catch (err) {
+    console.error(
+      `Failed to stat ${file}: ${err?.code ?? err?.message ?? err}`,
+    );
+    process.exit(1);
+  }
+}
+
+/** @param dir {string} @returns {Array<string>} */
+function readDir(dir) {
+  dir = path.resolve(dir);
+  let contents = dirs.get(dir);
+  if (!contents) {
+    try {
+      contents = fs.readdirSync(dir);
+    } catch {
+      contents = [];
+    }
+    dirs.set(dir, contents);
+  }
+  return contents;
+}
+
+/** @param dir {string} @returns {string} */
+function pickFormatter(file) {
+  const lang = extToLanguage[path.extname(file)];
+  const dir = path.dirname(file);
+  let c = walkUp(dir, (x) => cached.get(x) ?? cached.get(`${x}:${lang}`));
+  if (c) return c;
+
+  const possible = Object.keys(formatters).filter(
+    (x) =>
+      Array.isArray(formatters[x].languages) &&
+      formatters[x].languages.includes(lang),
+  );
+  const order = [...multis, ...possible];
+  return walkUp(dir, (x) => {
+    const children = readDir(x);
+    for (const fmt of order) {
+      let matches = false;
+      if (formatters[fmt].files === true) {
+        matches = true;
+      }
+      if (!matches) {
+        const filesToCheck = Array.isArray(formatters[fmt].files)
+          ? formatters[fmt].files.map((base) => ({ base, contents: true }))
+          : Object.entries(formatters[fmt].files)
+            .map(([base, contents]) => ({ base, contents }));
+        for (const { base, contents } of filesToCheck) {
+          if (base.includes("/")) {
+            matches = readDir(path.join(x, path.dirname(base))) //
+              .includes(path.basename(base));
+          } else {
+            matches = children.includes(base);
+          }
+          if (matches && typeof contents === "function") {
+            matches = !!contents(fs.readFileSync(path.join(x, base), "utf-8"));
+          }
+        }
+      }
+      if (matches) {
+        const formatterId = `${fmt}\0${x}`;
+        const k = multis.includes(fmt) ? x : `${x}:${lang}`;
+        cached.set(k, formatterId);
+        return formatterId;
+      }
+    }
+  }) ?? possible[0];
+}
+
+/** @param dir {string} @param find {(x: string) => any} */
+function walkUp(dir, find) {
+  do {
+    const found = find(dir);
+    if (found != null) return found;
+    const parent = path.dirname(dir);
+    if (parent === dir) break;
+    dir = parent;
+  } while (true);
+  return null;
+}
+
+/** @param dir {string} */
+function getGitIgnores(dir) {
+  if (!gitignore) return [];
+  if (dir.endsWith(sep)) dir = dir.slice(0, -1);
+  const files = fs.globSync(`${dir}${sep}{**${sep}*${sep},}.gitignore`, {});
+  const referenced = [];
+  for (const abs of files) {
+    const dir = path.dirname(abs);
+    referenced.push(dir);
+    if (!gitignores.has(dir)) gitignores.set(dir, readGitIgnore(dir));
+  }
+  do {
+    const parent = path.dirname(dir);
+    if (parent === dir || fs.existsSync(path.join(dir, ".git"))) break;
+    referenced.push(parent);
+    if (!gitignores.has(parent)) gitignores.set(parent, readGitIgnore(parent));
+    dir = parent;
+  } while (true);
+  return referenced.flatMap((root) =>
+    (gitignores.get(root) ?? [])
+      .filter((x) => x[0] !== "!")
+      .map(
+        (rule) => `${root}${sep}${rule[0] === "/" ? "" : `**${sep}`}${rule}`,
+      )
+  );
+}
+
+/** @param dir {string} */
+function readGitIgnore(dir) {
+  try {
+    return fs
+      .readFileSync(`${dir}${sep}.gitignore`, "utf-8")
+      .split("\n")
+      .map((line) => line.replace(/#.*$/, "").trim())
+      .filter(Boolean);
+  } catch {
+    return [];
+  }
+}
+
+function escapeGlob(str) {
+  return str.replace(/[\\*,{}]/g, "\\$&");
+}
+
+import * as child_process from "node:child_process";
+import * as fs from "node:fs";
+import * as path from "node:path";
+import * as readline from "node:readline";
+import * as events from "node:events";
+import process from "node:process";
+import assert from "node:assert";
diff --git a/packages/autofmt/default.nix b/packages/autofmt/default.nix
new file mode 100644
index 0000000000000000000000000000000000000000..54893c07aca0b08fc951b8dfee853e6df317f616
--- /dev/null
+++ b/packages/autofmt/default.nix
@@ -0,0 +1,14 @@
+{ pkgs, ... }:
+pkgs.writeShellApplication {
+  name = "autofmt";
+  runtimeInputs = with pkgs; [
+    # include only a couple of formatters by default
+    deno
+    nixfmt-rfc-style
+    dprint
+    rustfmt
+    zig
+    clang-tools
+  ];
+  text = ''exec deno run -A ${./autofmt.js} "$@"'';
+}