diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1dfc532e..18e82d09 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,9 +8,12 @@ All notable user-visible changes to Hunk are documented in this file.
 
 - Added Windows x64 prebuilt artifact publishing to the release workflow.
 - Added Nix flake app outputs for `nix run` and a named `hunk` package output.
+- Documented native Windows support in the README and contributor guide.
 
 ### Changed
 
+- Ported `build:npm`, `build:bin`, and `install:bin` from bash scripts to cross-platform Bun-runnable TypeScript so native Windows contributors no longer need Git Bash to build or install Hunk locally.
+
 ### Fixed
 
 ## [0.12.0-beta.1] - 2026-05-10
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f8d21869..91956e84 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -11,6 +11,7 @@ Requirements:
 - Bun 1.3+
 - Node.js 18+
 - Git
+- macOS, Linux, or Windows. The Windows path uses native Node/Bun on Windows 10/11 (x64); no WSL or Git Bash required.
 
 > Nix users can use `nix develop` or [direnv](https://direnv.net/) to enter a development shell.
 
diff --git a/README.md b/README.md
index d1bdce87..8923ce54 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ brew install modem-dev/tap/hunk
 Requirements:
 
 - Node.js 18+
-- macOS or Linux
+- macOS, Linux, or Windows
 - Git recommended for most workflows
 
 > Nix users can use the `default` package exported in `flake.nix` instead. See [nix/README.md](./nix/README.md) for details.
diff --git a/package.json b/package.json
index 8f7845db..313acabf 100644
--- a/package.json
+++ b/package.json
@@ -46,12 +46,12 @@
   "scripts": {
     "start": "bun run src/main.tsx",
     "dev": "bun --watch src/main.tsx",
-    "build:npm": "bash ./scripts/build-npm.sh",
-    "build:bin": "bash ./scripts/build-bin.sh",
+    "build:npm": "bun run ./scripts/build-npm.ts",
+    "build:bin": "bun run ./scripts/build-bin.ts",
     "build:prebuilt:npm": "bun run build:npm && bun run build:bin && bun run ./scripts/stage-prebuilt-npm.ts",
     "build:prebuilt:artifact": "bun run build:bin && bun run ./scripts/build-prebuilt-artifact.ts",
     "stage:prebuilt:release": "bun run build:npm && bun run ./scripts/stage-prebuilt-npm.ts --artifact-root ./dist/release/artifacts",
-    "install:bin": "bash ./scripts/install-bin.sh",
+    "install:bin": "bun run ./scripts/install-bin.ts",
     "typecheck": "tsc --noEmit",
     "format": "oxfmt --write .",
     "format:check": "oxfmt --check .",
diff --git a/scripts/build-bin.sh b/scripts/build-bin.sh
deleted file mode 100644
index c4c802fe..00000000
--- a/scripts/build-bin.sh
+++ /dev/null
@@ -1,16 +0,0 @@
-#!/usr/bin/env bash
-set -Eeuo pipefail
-
-repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-dist_dir="${repo_root}/dist"
-outfile="${dist_dir}/hunk"
-legacy_outfile="${dist_dir}/otdiff"
-
-mkdir -p "${dist_dir}"
-rm -f "${legacy_outfile}"
-
-BUN_TMPDIR="${repo_root}/.bun-tmp" \
-BUN_INSTALL="${repo_root}/.bun-install" \
-bun build --compile "${repo_root}/src/main.tsx" --outfile "${outfile}"
-
-printf 'Built %s\n' "${outfile}"
diff --git a/scripts/build-bin.ts b/scripts/build-bin.ts
new file mode 100644
index 00000000..2158d454
--- /dev/null
+++ b/scripts/build-bin.ts
@@ -0,0 +1,34 @@
+#!/usr/bin/env bun
+
+import { mkdirSync, rmSync } from "node:fs";
+import path from "node:path";
+
+const repoRoot = path.resolve(import.meta.dir, "..");
+const distDir = path.join(repoRoot, "dist");
+const binaryName = process.platform === "win32" ? "hunk.exe" : "hunk";
+const outfile = path.join(distDir, binaryName);
+const legacyOutfile = path.join(distDir, process.platform === "win32" ? "otdiff.exe" : "otdiff");
+
+mkdirSync(distDir, { recursive: true });
+rmSync(legacyOutfile, { force: true });
+
+const proc = Bun.spawnSync(
+  ["bun", "build", "--compile", path.join(repoRoot, "src", "main.tsx"), "--outfile", outfile],
+  {
+    cwd: repoRoot,
+    stdin: "inherit",
+    stdout: "inherit",
+    stderr: "inherit",
+    env: {
+      ...process.env,
+      BUN_TMPDIR: path.join(repoRoot, ".bun-tmp"),
+      BUN_INSTALL: path.join(repoRoot, ".bun-install"),
+    },
+  },
+);
+
+if (proc.exitCode !== 0) {
+  throw new Error(`bun build --compile failed with exit ${proc.exitCode}`);
+}
+
+console.log(`Built ${outfile}`);
diff --git a/scripts/build-npm.sh b/scripts/build-npm.sh
deleted file mode 100644
index 31697a8a..00000000
--- a/scripts/build-npm.sh
+++ /dev/null
@@ -1,44 +0,0 @@
-#!/usr/bin/env bash
-set -Eeuo pipefail
-
-repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-outdir="${repo_root}/dist/npm"
-types_outdir="${repo_root}/dist/npm-types"
-
-rm -rf "${outdir}"
-rm -rf "${types_outdir}"
-mkdir -p "${outdir}/opentui"
-
-BUN_TMPDIR="${repo_root}/.bun-tmp" \
-BUN_INSTALL="${repo_root}/.bun-install" \
-  bun build "${repo_root}/src/main.tsx" \
-    --target bun \
-    --format esm \
-    --outdir "${outdir}" \
-    --entry-naming main.js
-
-chmod 0755 "${outdir}/main.js"
-
-BUN_TMPDIR="${repo_root}/.bun-tmp" \
-BUN_INSTALL="${repo_root}/.bun-install" \
-  bun build "${repo_root}/src/opentui/index.ts" \
-    --target node \
-    --format esm \
-    --external react \
-    --external react/jsx-runtime \
-    --external react/jsx-dev-runtime \
-    --external @opentui/core \
-    --external @opentui/react \
-    --external @opentui/react/jsx-runtime \
-    --external @opentui/react/jsx-dev-runtime \
-    --external @pierre/diffs \
-    --outdir "${outdir}/opentui" \
-    --entry-naming index.js
-
-bun x tsc -p "${repo_root}/tsconfig.opentui.json"
-
-cp "${types_outdir}/opentui/"*.d.ts "${outdir}/opentui/"
-rm -rf "${types_outdir}"
-
-printf 'Built %s\n' "${outdir}/main.js"
-printf 'Built %s\n' "${outdir}/opentui/index.js"
diff --git a/scripts/build-npm.ts b/scripts/build-npm.ts
new file mode 100644
index 00000000..c4be9c6d
--- /dev/null
+++ b/scripts/build-npm.ts
@@ -0,0 +1,95 @@
+#!/usr/bin/env bun
+
+import { chmodSync, copyFileSync, mkdirSync, readdirSync, rmSync } from "node:fs";
+import path from "node:path";
+
+const repoRoot = path.resolve(import.meta.dir, "..");
+const outdir = path.join(repoRoot, "dist", "npm");
+const typesOutdir = path.join(repoRoot, "dist", "npm-types");
+const opentuiOutdir = path.join(outdir, "opentui");
+const opentuiTypesDir = path.join(typesOutdir, "opentui");
+
+const bunEnv = {
+  ...process.env,
+  BUN_TMPDIR: path.join(repoRoot, ".bun-tmp"),
+  BUN_INSTALL: path.join(repoRoot, ".bun-install"),
+};
+
+function runBun(args: string[]) {
+  const proc = Bun.spawnSync(["bun", ...args], {
+    cwd: repoRoot,
+    stdin: "inherit",
+    stdout: "inherit",
+    stderr: "inherit",
+    env: bunEnv,
+  });
+
+  if (proc.exitCode !== 0) {
+    throw new Error(`bun ${args.join(" ")} failed with exit ${proc.exitCode}`);
+  }
+}
+
+rmSync(outdir, { recursive: true, force: true });
+rmSync(typesOutdir, { recursive: true, force: true });
+mkdirSync(opentuiOutdir, { recursive: true });
+
+runBun([
+  "build",
+  path.join(repoRoot, "src", "main.tsx"),
+  "--target",
+  "bun",
+  "--format",
+  "esm",
+  "--outdir",
+  outdir,
+  "--entry-naming",
+  "main.js",
+]);
+
+const mainJs = path.join(outdir, "main.js");
+// chmod is a no-op on Windows; preserve exec bits on Unix so the bin runs in npm-installed packages.
+if (process.platform !== "win32") {
+  chmodSync(mainJs, 0o755);
+}
+
+runBun([
+  "build",
+  path.join(repoRoot, "src", "opentui", "index.ts"),
+  "--target",
+  "node",
+  "--format",
+  "esm",
+  "--external",
+  "react",
+  "--external",
+  "react/jsx-runtime",
+  "--external",
+  "react/jsx-dev-runtime",
+  "--external",
+  "@opentui/core",
+  "--external",
+  "@opentui/react",
+  "--external",
+  "@opentui/react/jsx-runtime",
+  "--external",
+  "@opentui/react/jsx-dev-runtime",
+  "--external",
+  "@pierre/diffs",
+  "--outdir",
+  opentuiOutdir,
+  "--entry-naming",
+  "index.js",
+]);
+
+runBun(["x", "tsc", "-p", path.join(repoRoot, "tsconfig.opentui.json")]);
+
+for (const entry of readdirSync(opentuiTypesDir)) {
+  if (entry.endsWith(".d.ts")) {
+    copyFileSync(path.join(opentuiTypesDir, entry), path.join(opentuiOutdir, entry));
+  }
+}
+
+rmSync(typesOutdir, { recursive: true, force: true });
+
+console.log(`Built ${mainJs}`);
+console.log(`Built ${path.join(opentuiOutdir, "index.js")}`);
diff --git a/scripts/check-pack.ts b/scripts/check-pack.ts
index 934846ab..d0baae92 100644
--- a/scripts/check-pack.ts
+++ b/scripts/check-pack.ts
@@ -1,5 +1,7 @@
 #!/usr/bin/env bun
 
+import { npmCommand } from "./script-helpers";
+
 interface PackedFile {
   path: string;
   size: number;
@@ -13,7 +15,7 @@ interface PackResult {
   files: PackedFile[];
 }
 
-const proc = Bun.spawnSync(["npm", "pack", "--dry-run", "--json"], {
+const proc = Bun.spawnSync([npmCommand, "pack", "--dry-run", "--json"], {
   cwd: process.cwd(),
   stdin: "ignore",
   stdout: "pipe",
diff --git a/scripts/check-prebuilt-pack.ts b/scripts/check-prebuilt-pack.ts
index 8b34a79e..808e6c40 100644
--- a/scripts/check-prebuilt-pack.ts
+++ b/scripts/check-prebuilt-pack.ts
@@ -3,6 +3,7 @@
 import { existsSync, readdirSync } from "node:fs";
 import path from "node:path";
 import { releaseNpmDir } from "./prebuilt-package-helpers";
+import { npmCommand } from "./script-helpers";
 
 interface PackedFile {
   path: string;
@@ -15,7 +16,7 @@ interface PackResult {
 }
 
 function runPackDryRun(cwd: string) {
-  const proc = Bun.spawnSync(["npm", "pack", "--dry-run", "--json"], {
+  const proc = Bun.spawnSync([npmCommand, "pack", "--dry-run", "--json"], {
     cwd,
     stdin: "ignore",
     stdout: "pipe",
diff --git a/scripts/install-bin.sh b/scripts/install-bin.sh
deleted file mode 100644
index cc1d1c76..00000000
--- a/scripts/install-bin.sh
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/usr/bin/env bash
-set -Eeuo pipefail
-
-repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-binary_path="${repo_root}/dist/hunk"
-install_dir="${HUNK_INSTALL_DIR:-${HOME}/.local/bin}"
-install_path="${install_dir}/hunk"
-legacy_install_path="${install_dir}/otdiff"
-
-bash "${repo_root}/scripts/build-bin.sh"
-
-mkdir -p "${install_dir}"
-install -m 0755 "${binary_path}" "${install_path}"
-rm -f "${legacy_install_path}"
-
-printf 'Installed %s\n' "${install_path}"
-
-case ":${PATH}:" in
-  *":${install_dir}:"*) ;;
-  *)
-    printf 'Warning: %s is not on PATH\n' "${install_dir}" >&2
-    ;;
-esac
diff --git a/scripts/install-bin.ts b/scripts/install-bin.ts
new file mode 100644
index 00000000..e531d088
--- /dev/null
+++ b/scripts/install-bin.ts
@@ -0,0 +1,60 @@
+#!/usr/bin/env bun
+
+import { chmodSync, copyFileSync, mkdirSync, rmSync } from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const repoRoot = path.resolve(import.meta.dir, "..");
+const isWindows = process.platform === "win32";
+const binaryName = isWindows ? "hunk.exe" : "hunk";
+const legacyBinaryName = isWindows ? "otdiff.exe" : "otdiff";
+const binaryPath = path.join(repoRoot, "dist", binaryName);
+
+function defaultInstallDir() {
+  if (isWindows) {
+    const base = process.env.LOCALAPPDATA ?? path.join(os.homedir(), "AppData", "Local");
+    return path.join(base, "Programs", "hunk");
+  }
+
+  return path.join(os.homedir(), ".local", "bin");
+}
+
+const installDir = process.env.HUNK_INSTALL_DIR ?? defaultInstallDir();
+const installPath = path.join(installDir, binaryName);
+const legacyInstallPath = path.join(installDir, legacyBinaryName);
+
+const buildScript = path.join(repoRoot, "scripts", "build-bin.ts");
+const build = Bun.spawnSync(["bun", "run", buildScript], {
+  cwd: repoRoot,
+  stdin: "inherit",
+  stdout: "inherit",
+  stderr: "inherit",
+  env: process.env,
+});
+
+if (build.exitCode !== 0) {
+  throw new Error(`scripts/build-bin.ts failed with exit ${build.exitCode}`);
+}
+
+mkdirSync(installDir, { recursive: true });
+copyFileSync(binaryPath, installPath);
+if (!isWindows) {
+  chmodSync(installPath, 0o755);
+}
+rmSync(legacyInstallPath, { force: true });
+
+console.log(`Installed ${installPath}`);
+
+const pathEntries = (process.env.PATH ?? "").split(path.delimiter).filter(Boolean);
+const installDirOnPath = pathEntries.some((entry) => {
+  // Windows paths are case-insensitive; normalize both sides for the comparison.
+  const normalizedEntry = isWindows ? path.normalize(entry).toLowerCase() : path.normalize(entry);
+  const normalizedInstallDir = isWindows
+    ? path.normalize(installDir).toLowerCase()
+    : path.normalize(installDir);
+  return normalizedEntry === normalizedInstallDir;
+});
+
+if (!installDirOnPath) {
+  console.warn(`Warning: ${installDir} is not on PATH`);
+}
diff --git a/scripts/publish-prebuilt-npm.ts b/scripts/publish-prebuilt-npm.ts
index 1d6ebcab..d830c05e 100644
--- a/scripts/publish-prebuilt-npm.ts
+++ b/scripts/publish-prebuilt-npm.ts
@@ -3,6 +3,7 @@
 import { existsSync, readdirSync, readFileSync } from "node:fs";
 import path from "node:path";
 import { releaseNpmDir } from "./prebuilt-package-helpers";
+import { npmCommand } from "./script-helpers";
 
 type PackageJson = {
   name: string;
@@ -41,7 +42,7 @@ function parseArgs(argv: string[]) {
 }
 
 function npmViewExists(name: string, version: string) {
-  const proc = Bun.spawnSync(["npm", "view", `${name}@${version}`, "version"], {
+  const proc = Bun.spawnSync([npmCommand, "view", `${name}@${version}`, "version"], {
     stdin: "ignore",
     stdout: "pipe",
     stderr: "ignore",
@@ -70,7 +71,7 @@ function publishDirectory(directory: string, dryRun: boolean, npmTag: string) {
     args.push("--dry-run");
   }
 
-  const proc = Bun.spawnSync(["npm", ...args], {
+  const proc = Bun.spawnSync([npmCommand, ...args], {
     cwd: directory,
     stdin: "ignore",
     stdout: "inherit",
diff --git a/scripts/script-helpers.ts b/scripts/script-helpers.ts
new file mode 100644
index 00000000..428b1763
--- /dev/null
+++ b/scripts/script-helpers.ts
@@ -0,0 +1,37 @@
+#!/usr/bin/env bun
+
+/**
+ * Shared cross-platform helpers for Bun-driven repo scripts.
+ *
+ * On Windows, Node ships `npm` (a shell-script shim) alongside `npm.cmd`. Bun
+ * (and Node `child_process` without `shell: true`) cannot execute the shim
+ * directly, so we must spawn the `.cmd` wrapper instead. The helpers below
+ * give scripts one place to resolve those names.
+ */
+
+/** Command name to invoke `npm` from Bun.spawn on the current platform. */
+export const npmCommand = process.platform === "win32" ? "npm.cmd" : "npm";
+
+/**
+ * Build a child-process env that overrides PATH cleanly on every platform.
+ *
+ * Windows environment variables are case-insensitive, but `{ ...process.env }`
+ * preserves whatever case Bun reported (often `Path`). Setting `PATH: ...` on
+ * top of that produces an env object with both `Path` (the original system
+ * value) and `PATH` (the sanitized value); the child inherits both, and
+ * Windows resolves lookups against the un-normalized union, defeating any
+ * attempt to scope PATH. We strip every case-variant first, then set PATH.
+ */
+export function envWithPath(
+  path: string,
+  base: NodeJS.ProcessEnv = process.env,
+): NodeJS.ProcessEnv {
+  const next: NodeJS.ProcessEnv = {};
+  for (const [key, value] of Object.entries(base)) {
+    if (key.toLowerCase() !== "path") {
+      next[key] = value;
+    }
+  }
+  next.PATH = path;
+  return next;
+}
diff --git a/scripts/smoke-prebuilt-install.ts b/scripts/smoke-prebuilt-install.ts
index 79c46d7c..4c9bcceb 100644
--- a/scripts/smoke-prebuilt-install.ts
+++ b/scripts/smoke-prebuilt-install.ts
@@ -16,6 +16,7 @@ import {
   getHostPlatformPackageSpec,
   releaseNpmDir,
 } from "./prebuilt-package-helpers";
+import { envWithPath, npmCommand } from "./script-helpers";
 
 function run(command: string[], options?: { cwd?: string; env?: NodeJS.ProcessEnv }) {
   const proc = Bun.spawnSync(command, {
@@ -80,9 +81,11 @@ try {
 
   const nodePath = commandPath("node");
   const nodeDir = path.dirname(nodePath);
-  const bashDir = commandDirectory("bash");
+  // bash is required on Unix where the npm-installed wrapper shells out via `#!/usr/bin/env bash`,
+  // but the Windows `hunk.cmd` shim does not need bash on PATH.
+  const bashDir = process.platform === "win32" ? undefined : commandDirectory("bash");
 
-  run(["npm", "pack", "--pack-destination", packageDir], {
+  run([npmCommand, "pack", "--pack-destination", packageDir], {
     cwd: path.join(releaseRoot, hostSpec.packageName),
   });
 
@@ -102,19 +105,19 @@ try {
   };
   writeFileSync(smokeManifestPath, `${JSON.stringify(smokeManifest, null, 2)}\n`);
 
-  run(["npm", "pack", "--pack-destination", packageDir], {
+  run([npmCommand, "pack", "--pack-destination", packageDir], {
     cwd: smokePackageDir,
   });
   const metaTarball = path.join(packageDir, `hunkdiff-${packageVersion}.tgz`);
 
-  run(["npm", "install", "-g", "--prefix", installDir, metaTarball]);
+  run([npmCommand, "install", "-g", "--prefix", installDir, metaTarball]);
 
   const installedBinDir = process.platform === "win32" ? installDir : path.join(installDir, "bin");
   const installedPackageRoot =
     process.platform === "win32"
       ? path.join(installDir, "node_modules", "hunkdiff")
       : path.join(installDir, "lib", "node_modules", "hunkdiff");
-  const sanitizedPath = [installedBinDir, nodeDir, bashDir].join(path.delimiter);
+  const sanitizedPath = [installedBinDir, nodeDir, bashDir].filter(Boolean).join(path.delimiter);
   const installedHunk = path.join(
     installedBinDir,
     process.platform === "win32" ? "hunk.cmd" : "hunk",
@@ -126,10 +129,7 @@ try {
     "bin",
     binaryFilenameForSpec(hostSpec),
   );
-  const commandEnv = {
-    ...process.env,
-    PATH: sanitizedPath,
-  };
+  const commandEnv = envWithPath(sanitizedPath);
 
   if (process.platform !== "win32") {
     const installedBinaryMode = statSync(installedPlatformBinary).mode & 0o777;
diff --git a/scripts/stage-prebuilt-npm.ts b/scripts/stage-prebuilt-npm.ts
index 66989747..fb892b21 100644
--- a/scripts/stage-prebuilt-npm.ts
+++ b/scripts/stage-prebuilt-npm.ts
@@ -171,12 +171,13 @@ const artifactRoot = options.artifactRoot ? path.resolve(options.artifactRoot) :
 rmSync(releaseRoot, { recursive: true, force: true });
 ensureDirectory(releaseRoot);
 
+const hostSpec = artifactRoot ? undefined : getHostPlatformPackageSpec();
 const artifacts = artifactRoot
   ? collectArtifactSpecs(artifactRoot)
   : [
       {
-        spec: getHostPlatformPackageSpec(),
-        compiledBinary: path.join(repoRoot, "dist", "hunk"),
+        spec: hostSpec!,
+        compiledBinary: path.join(repoRoot, "dist", binaryFilenameForSpec(hostSpec!)),
       },
     ];
 
@@ -195,5 +196,5 @@ for (const spec of stagedSpecs) {
 if (artifactRoot) {
   console.log(`Artifacts source: ${artifactRoot}`);
 } else {
-  console.log(`Artifacts source: ${path.join(repoRoot, "dist", "hunk")}`);
+  console.log(`Artifacts source: ${path.join(repoRoot, "dist", binaryFilenameForSpec(hostSpec!))}`);
 }