diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index e1b6302..b702ff6 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -7,7 +7,7 @@ jobs:
         strategy:
             matrix:
                 node-version:
-                - 18.x
+                - 20.x
                 - 22.x
                 - latest
         steps:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2b12557..650a902 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,18 @@
 faucet-pipeline-static version history
 ======================================
 
+v2.2.0
+------
+
+_TBD_
+
+maintenance release to update dependencies; no significant changes
+
+improvements for developers:
+
+* it now exposes `buildProcessPipeline` for other pipelines that convert directories of files instead of single files
+
+
 v2.1.0
 ------
 
diff --git a/index.js b/index.js
deleted file mode 100644
index 40833ac..0000000
--- a/index.js
+++ /dev/null
@@ -1,91 +0,0 @@
-let { readFile, stat } = require("fs").promises;
-let path = require("path");
-let { FileFinder } = require("faucet-pipeline-core/lib/util/files/finder");
-
-module.exports = {
-	key: "static",
-	bucket: "static",
-	plugin: faucetStatic
-};
-
-function faucetStatic(config, assetManager, { compact } = {}) {
-	let copiers = config.map(copyConfig =>
-		makeCopier(copyConfig, assetManager, { compact }));
-
-	return filepaths => Promise.all(copiers.map(copy => copy(filepaths)));
-}
-
-function makeCopier(copyConfig, assetManager, { compact } = {}) {
-	let source = assetManager.resolvePath(copyConfig.source);
-	let target = assetManager.resolvePath(copyConfig.target, {
-		enforceRelative: true
-	});
-	let fileFinder = new FileFinder(source, {
-		skipDotfiles: true,
-		filter: copyConfig.filter
-	});
-	let { fingerprint } = copyConfig;
-	let plugins = determinePlugins(compact, copyConfig);
-
-	return filepaths => {
-		return Promise.all([
-			(filepaths ? fileFinder.match(filepaths) : fileFinder.all()),
-			determineTargetDir(source, target)
-		]).then(([fileNames, targetDir]) => {
-			return processFiles(fileNames, {
-				assetManager, source, target, targetDir, plugins, fingerprint
-			});
-		});
-	};
-}
-
-function determinePlugins(compact, copyConfig) {
-	if(!compact) {
-		return {};
-	}
-
-	return copyConfig.compact || {};
-}
-
-// If `source` is a directory, `target` is used as target directory -
-// otherwise, `target`'s parent directory is used
-function determineTargetDir(source, target) {
-	return stat(source).
-		then(results => results.isDirectory() ? target : path.dirname(target));
-}
-
-function processFiles(fileNames, config) {
-	return Promise.all(fileNames.map(fileName => processFile(fileName, config)));
-}
-
-async function processFile(fileName,
-		{ source, target, targetDir, fingerprint, assetManager, plugins }) {
-	let sourcePath = path.join(source, fileName);
-	let targetPath = path.join(target, fileName);
-
-	try {
-		var content = await readFile(sourcePath); // eslint-disable-line no-var
-	} catch(err) {
-		if(err.code !== "ENOENT") {
-			throw err;
-		}
-		console.error(`WARNING: \`${sourcePath}\` no longer exists`);
-		return;
-	}
-
-	let type = determineFileType(sourcePath);
-	if(type && plugins[type]) {
-		let plugin = plugins[type];
-		content = await plugin(content);
-	}
-
-	let options = { targetDir };
-	if(fingerprint !== undefined) {
-		options.fingerprint = fingerprint;
-	}
-	return assetManager.writeFile(targetPath, content, options);
-}
-
-function determineFileType(sourcePath) {
-	return path.extname(sourcePath).substr(1).toLowerCase();
-}
diff --git a/lib/index.js b/lib/index.js
new file mode 100644
index 0000000..a2ad2a7
--- /dev/null
+++ b/lib/index.js
@@ -0,0 +1,72 @@
+import { buildProcessPipeline } from "./util.js";
+import { readFile } from "node:fs/promises";
+import path from "node:path";
+
+export const key = "static";
+export const bucket = "static";
+
+/** @type FaucetPlugin<Config> */
+export function plugin(config, assetManager, options) {
+	let pipeline = config.map(copyConfig => {
+		let processFile = buildProcessFile(copyConfig, options);
+		let { source, target, filter } = copyConfig;
+		return buildProcessPipeline(source, target, processFile, assetManager, filter);
+	});
+
+	return filepaths => Promise.all(pipeline.map(copy => copy(filepaths)));
+}
+
+/**
+ * Returns a function that copies a single file with optional compactor
+ *
+ * @param {Config} copyConfig
+ * @param {FaucetPluginOptions} options
+ * @returns {ProcessFile}
+ */
+function buildProcessFile(copyConfig, options) {
+	let compactors = (options.compact && copyConfig.compact) || {};
+
+	return async function(filename,
+			{ source, target, targetDir, assetManager }) {
+		let sourcePath = path.join(source, filename);
+		let targetPath = path.join(target, filename);
+
+		let content;
+		try {
+			content = await readFile(sourcePath);
+		} catch(err) {
+			// @ts-expect-error TS2345
+			if(err.code !== "ENOENT") {
+				throw err;
+			}
+			console.error(`WARNING: \`${sourcePath}\` no longer exists`);
+			return;
+		}
+
+		let fileExtension = path.extname(sourcePath).substr(1).toLowerCase();
+		if(fileExtension && compactors[fileExtension]) {
+			let compactor = compactors[fileExtension];
+			content = await compactor(content);
+		}
+
+		/** @type WriteFileOpts */
+		let options = { targetDir };
+		if(copyConfig.fingerprint !== undefined) {
+			options.fingerprint = copyConfig.fingerprint;
+		}
+		return assetManager.writeFile(targetPath, content, options);
+	};
+}
+
+/**
+ * @import {
+ *     Config,
+ *     ProcessFile
+ * } from "./types.ts"
+ *
+ * @import {
+ *     FaucetPlugin,
+ *     FaucetPluginOptions,
+ *     WriteFileOpts,
+ * } from "faucet-pipeline-core/lib/types.ts"
+*/
diff --git a/lib/types.ts b/lib/types.ts
new file mode 100644
index 0000000..357269a
--- /dev/null
+++ b/lib/types.ts
@@ -0,0 +1,39 @@
+import { AssetManager } from "faucet-pipeline-core/lib/types.ts"
+
+export interface Config {
+	source: string,
+	target: string,
+	targetDir: string,
+	fingerprint?: boolean,
+	compact?: CompactorMap,
+	assetManager: AssetManager,
+	filter?: Filter
+}
+
+export interface CompactorMap {
+	[fileExtension: string]: Compactor
+}
+
+export interface Compactor {
+	(contact: Buffer): Promise<Buffer>
+}
+
+export interface ProcessFile {
+	(filename: string, opts: ProcessFileOptions): Promise<unknown>
+}
+
+export interface ProcessFileOptions {
+	source: string,
+	target: string,
+	targetDir: string,
+	assetManager: AssetManager,
+}
+
+export interface FileFinderOptions {
+	skipDotfiles: boolean,
+	filter?: Filter
+}
+
+export interface Filter {
+	(filename: string): boolean
+}
diff --git a/lib/util.js b/lib/util.js
new file mode 100644
index 0000000..2084d9d
--- /dev/null
+++ b/lib/util.js
@@ -0,0 +1,123 @@
+import { readdir, stat } from "node:fs/promises";
+import path from "node:path";
+
+/**
+ * Creates a processor for a single configuration
+ *
+ * @param {string} source - the source folder or file for this pipeline
+ * @param {string} target - the target folder or file for this pipeline
+ * @param {ProcessFile} processFile - process a single file
+ * @param {AssetManager} assetManager
+ * @param {Filter} [filter] - optional filter based on filenames
+ * @returns {FaucetPluginFunc}
+ */
+export function buildProcessPipeline(source, target, processFile, assetManager, filter) {
+	source = assetManager.resolvePath(source);
+	target = assetManager.resolvePath(target, {
+		enforceRelative: true
+	});
+	let fileFinder = new FileFinder(source, {
+		skipDotfiles: true,
+		filter
+	});
+
+	return async filepaths => {
+		let [filenames, targetDir] = await Promise.all([
+			(filepaths ? fileFinder.match(filepaths) : fileFinder.all()),
+			determineTargetDir(source, target)
+		]);
+
+		return Promise.all(filenames.map(filename => processFile(filename, {
+			assetManager, source, target, targetDir
+		})));
+	};
+}
+
+/**
+ * If `source` is a directory, `target` is used as target directory -
+ * otherwise, `target`'s parent directory is used
+ *
+ * @param {string} source
+ * @param {string} target
+ * @returns {Promise<string>}
+ */
+async function determineTargetDir(source, target) {
+	let results = await stat(source);
+	return results.isDirectory() ? target : path.dirname(target);
+}
+
+class FileFinder {
+	/**
+	 * @param {string} root
+	 * @param {FileFinderOptions} options
+	 */
+	constructor(root, { skipDotfiles, filter }) {
+		this._root = root;
+
+		/**
+		 * @param {string} filename
+		 * @return {boolean}
+		 */
+		this._filter = filename => {
+			if(skipDotfiles && path.basename(filename).startsWith(".")) {
+				return false;
+			}
+			return filter ? filter(filename) : true;
+		};
+	}
+
+	/**
+	 * A list of relative file paths within the respective directory
+	 *
+	 * @returns {Promise<string[]>}
+	 */
+	async all() {
+		let filenames = await tree(this._root);
+		return filenames.filter(this._filter);
+	}
+
+	/**
+	 * All file paths that match the filter function
+	 *
+	 * @param {string[]} filepaths
+	 * @returns {Promise<string[]>}
+	 */
+	async match(filepaths) {
+		return filepaths.map(filepath => path.relative(this._root, filepath)).
+			filter(filename => !filename.startsWith("..")).
+			filter(this._filter);
+	}
+}
+
+/**
+ * Flat list of all files of a directory tree
+ *
+ * @param {string} filepath
+ * @param {string} referenceDir
+ * @returns {Promise<string[]>}
+ */
+async function tree(filepath, referenceDir = filepath) {
+	let stats = await stat(filepath);
+
+	if(!stats.isDirectory()) {
+		return [path.relative(referenceDir, filepath)];
+	}
+
+	let entries = await Promise.all((await readdir(filepath)).map(entry => {
+		return tree(path.join(filepath, entry), referenceDir);
+	}));
+	return entries.flat();
+}
+
+/**
+ * @import {
+ *     Filter,
+ *     FileFinderOptions,
+ *     ProcessFile
+ * } from "./types.ts"
+ *
+ * @import {
+ *     AssetManager,
+ *     FaucetPluginFunc,
+ * } from "faucet-pipeline-core/lib/types.ts"
+*/
diff --git a/package.json b/package.json
index d6c5a77..c64c1e5 100644
--- a/package.json
+++ b/package.json
@@ -1,12 +1,14 @@
 {
 	"name": "faucet-pipeline-static",
-	"version": "2.1.0",
+	"version": "2.2.0",
 	"description": "static files for faucet-pipeline",
-	"main": "index.js",
+	"main": "./lib/index.js",
+	"type": "module",
 	"scripts": {
-		"test": "npm-run-all --parallel lint test:cli",
+		"test": "npm run lint && npm run typecheck && npm run test:cli",
 		"test:cli": "./test/run",
-		"lint": "eslint --cache index.js test && echo ✓"
+		"lint": "eslint --cache ./lib ./test && echo ✓",
+		"typecheck": "tsc"
 	},
 	"repository": {
 		"type": "git",
@@ -19,15 +21,16 @@
 	},
 	"homepage": "https://www.faucet-pipeline.org",
 	"engines": {
-		"node": ">= 18"
+		"node": ">= 20.19.0"
 	},
 	"dependencies": {
-		"faucet-pipeline-core": "^3.0.0"
+		"faucet-pipeline-core": "git+https://github.com/faucet-pipeline/faucet-pipeline-core.git#util-cleanup"
 	},
 	"devDependencies": {
+		"@types/node": "^22.13.10",
 		"eslint-config-fnd": "^1.13.0",
 		"json-diff": "^1.0.0",
-		"npm-run-all": "^4.1.5",
-		"release-util-fnd": "^3.0.0"
+		"release-util-fnd": "^3.0.0",
+		"typescript": "^5.8.2"
 	}
 }
diff --git a/test/test_basic/faucet.config.js b/test/test_basic/faucet.config.js
index c075370..7e9350c 100644
--- a/test/test_basic/faucet.config.js
+++ b/test/test_basic/faucet.config.js
@@ -1,10 +1,9 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist"
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src",
+	target: "./dist"
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_fingerprint/faucet.config.js b/test/test_fingerprint/faucet.config.js
index 1bd7f28..340eab5 100644
--- a/test/test_fingerprint/faucet.config.js
+++ b/test/test_fingerprint/faucet.config.js
@@ -1,13 +1,13 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist"
-	}],
-	manifest: {
-		target: "./dist/manifest.json"
-	},
-	plugins: [path.resolve(__dirname, "../..")]
+const config = [{
+	source: "./src",
+	target: "./dist"
+}];
+export { config as static };
+
+export const manifest = {
+	target: "./dist/manifest.json"
 };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_key_config/faucet.config.js b/test/test_key_config/faucet.config.js
index 3ff6f64..6a1a831 100644
--- a/test/test_key_config/faucet.config.js
+++ b/test/test_key_config/faucet.config.js
@@ -1,14 +1,14 @@
-"use strict";
-let path = require("path");
+import { resolve, relative } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist"
-	}],
-	manifest: {
-		target: "./dist/manifest.json",
-		key: (f, targetDir) => path.relative(targetDir, f)
-	},
-	plugins: [path.resolve(__dirname, "../..")]
+const config = [{
+	source: "./src",
+	target: "./dist"
+}];
+export { config as static };
+
+export const manifest = {
+	target: "./dist/manifest.json",
+	key: (f, targetDir) => relative(targetDir, f)
 };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_key_for_single_file/faucet.config.js b/test/test_key_for_single_file/faucet.config.js
index 4642185..df75818 100644
--- a/test/test_key_for_single_file/faucet.config.js
+++ b/test/test_key_for_single_file/faucet.config.js
@@ -1,14 +1,14 @@
-"use strict";
-let path = require("path");
+import { resolve, relative } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src/test.txt",
-		target: "./dist/test.txt"
-	}],
-	manifest: {
-		target: "./dist/manifest.json",
-		key: (f, targetDir) => path.relative(targetDir, f)
-	},
-	plugins: [path.resolve(__dirname, "../..")]
+const config = [{
+	source: "./src/test.txt",
+	target: "./dist/test.txt"
+}];
+export { config as static };
+
+export const manifest = {
+	target: "./dist/manifest.json",
+	key: (f, targetDir) => relative(targetDir, f)
 };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_manifest_base_uri/faucet.config.js b/test/test_manifest_base_uri/faucet.config.js
index 1dd1fca..dbd6b42 100644
--- a/test/test_manifest_base_uri/faucet.config.js
+++ b/test/test_manifest_base_uri/faucet.config.js
@@ -1,14 +1,14 @@
-"use strict";
-let path = require("path");
+import { resolve, relative } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist"
-	}],
-	manifest: {
-		target: "./dist/manifest.json",
-		value: f => `/assets/${path.relative("./dist", f)}`
-	},
-	plugins: [path.resolve(__dirname, "../..")]
+const config = [{
+	source: "./src",
+	target: "./dist"
+}];
+export { config as static };
+
+export const manifest = {
+	target: "./dist/manifest.json",
+	value: f => `/assets/${relative("./dist", f)}`
 };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_match_dirname/faucet.config.js b/test/test_match_dirname/faucet.config.js
index d17a793..92ac275 100644
--- a/test/test_match_dirname/faucet.config.js
+++ b/test/test_match_dirname/faucet.config.js
@@ -1,11 +1,10 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist",
-		filter: path => path.startsWith("inner/")
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src",
+	target: "./dist",
+	filter: path => path.startsWith("inner/")
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_match_extension/faucet.config.js b/test/test_match_extension/faucet.config.js
index ca52325..4637f00 100644
--- a/test/test_match_extension/faucet.config.js
+++ b/test/test_match_extension/faucet.config.js
@@ -1,11 +1,10 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist",
-		filter: path => path.endsWith(".txt")
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src",
+	target: "./dist",
+	filter: path => path.endsWith(".txt")
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_match_multiple/faucet.config.js b/test/test_match_multiple/faucet.config.js
index 10c5111..d8e6288 100644
--- a/test/test_match_multiple/faucet.config.js
+++ b/test/test_match_multiple/faucet.config.js
@@ -1,11 +1,10 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist",
-		filter: path => path.endsWith(".txt") && !path.startsWith("inner/")
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src",
+	target: "./dist",
+	filter: path => path.endsWith(".txt") && !path.startsWith("inner/")
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_match_negation/faucet.config.js b/test/test_match_negation/faucet.config.js
index ec5b8cf..7ba2216 100644
--- a/test/test_match_negation/faucet.config.js
+++ b/test/test_match_negation/faucet.config.js
@@ -1,11 +1,10 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist",
-		filter: path => !path.endsWith("/test2.txt")
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src",
+	target: "./dist",
+	filter: path => !path.endsWith("/test2.txt")
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_no_fingerprint/faucet.config.js b/test/test_no_fingerprint/faucet.config.js
index f46b3cf..0731458 100644
--- a/test/test_no_fingerprint/faucet.config.js
+++ b/test/test_no_fingerprint/faucet.config.js
@@ -1,14 +1,13 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src",
-		target: "./dist/no-fingerprint",
-		fingerprint: false
-	}, {
-		source: "./src",
-		target: "./dist/fingerprint"
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src",
+	target: "./dist/no-fingerprint",
+	fingerprint: false
+}, {
+	source: "./src",
+	target: "./dist/fingerprint"
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/test/test_single/faucet.config.js b/test/test_single/faucet.config.js
index 4fac638..e6ae6c4 100644
--- a/test/test_single/faucet.config.js
+++ b/test/test_single/faucet.config.js
@@ -1,10 +1,9 @@
-"use strict";
-let path = require("path");
+import { resolve } from "node:path";
 
-module.exports = {
-	static: [{
-		source: "./src.txt",
-		target: "./dist/dist.txt"
-	}],
-	plugins: [path.resolve(__dirname, "../..")]
-};
+const config = [{
+	source: "./src.txt",
+	target: "./dist/dist.txt"
+}];
+export { config as static };
+
+export const plugins = [resolve(import.meta.dirname, "../..")];
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..c09dc11
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,14 @@
+{
+	"compilerOptions": {
+		"allowJs": true,
+		"checkJs": true,
+		"noEmit": true,
+		"strict": true,
+		"allowImportingTsExtensions": true,
+		"lib": ["dom", "es2023"],
+		"module": "nodenext",
+		"isolatedModules": true,
+		"erasableSyntaxOnly": true
+	},
+	"exclude": ["./test/**"]
+}