diff --git a/CHANGELOG.md b/CHANGELOG.md
index db5c848..44ba693 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 #### Security
 
 
+## [2.4.0] - 2023-06-27
+#### Added
+- multiple path hashing options (thanks @trevor-vaughan)
+
+
 ## [2.3.0] - 2023-05-22
 #### Added
 - `ttl` (time to live) to expire caches (thanks @douglaslinsmeyer)
diff --git a/README.md b/README.md
index 787bac3..0267ced 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,16 @@ A super-fast, promise-based cache that reads and writes to the file-system.
 
     npm install --save file-system-cache
 
+Import
+
+```ts
+import Cache from 'file-system-cache';
+
+   // or ↑↓ (equivalent)
+
+import { Cache } from 'file-system-cache';
+```
+
 ## Usage (API)
 
 Create an instance of the cache optionally giving it a folder location to store files within.
@@ -17,9 +27,10 @@ Create an instance of the cache optionally giving it a folder location to store
 import Cache from "file-system-cache";
 
 const cache = Cache({
-  basePath: "./.cache", // Optional. Path where cache files are stored (default).
-  ns: "my-namespace",   // Optional. A grouping namespace for items.
-  ttl: 60               // Optional. A time-to-live for how long the cached item is valid (secs).
+  basePath: "./.cache", // (optional) Path where cache files are stored (default).
+  ns: "my-namespace",   // (optional) A grouping namespace for items.
+  hash: "sha1"          // (optional) A hashing algorithm used within the cache key.
+  ttl: 60               // (optional) A time-to-live (in secs) on how long an item remains cached.
 });
 ```
 
diff --git a/package.json b/package.json
index 98f0050..13547e6 100644
--- a/package.json
+++ b/package.json
@@ -1,27 +1,29 @@
 {
   "name": "file-system-cache",
-  "version": "2.3.0",
+  "version": "2.4.0",
   "description": "A super-fast, promise-based cache that reads and writes to the file-system.",
   "main": "./lib/index.js",
   "scripts": {
     "test": "ts-mocha -p tsconfig.json src/**/*.TEST.ts",
     "build": "tsc",
-    "prepublish": "npm test && npm run build"
+    "prepublish": "npm test && npm run build",
+    "gen:hashtype": "ts-node-esm -T ./script.ts/generate-hashtype.ts"
   },
   "dependencies": {
     "fs-extra": "11.1.1",
     "ramda": "0.29.0"
   },
   "devDependencies": {
-    "@types/chai": "4.3.4",
+    "@types/chai": "4.3.5",
     "@types/expect": "24.3.0",
     "@types/fs-extra": "11.0.1",
     "@types/mocha": "10.0.1",
-    "@types/ramda": "0.29.1",
+    "@types/ramda": "0.29.2",
     "chai": "4.3.7",
     "mocha": "10.2.0",
     "ts-mocha": "10.0.0",
-    "typescript": "5.0.4"
+    "ts-node": "10.9.1",
+    "typescript": "5.1.3"
   },
   "repository": {
     "type": "git",
diff --git a/script.ts/generate-hashtype.ts b/script.ts/generate-hashtype.ts
new file mode 100644
index 0000000..6a55d24
--- /dev/null
+++ b/script.ts/generate-hashtype.ts
@@ -0,0 +1,45 @@
+#!/usr/bin/env ts-node
+import { crypto, fs, fsPath } from '../src/common';
+
+const HashUnionType = {
+  /**
+   * Generate the union type.
+   */
+  generate() {
+    const names = crypto.getHashes().map((hash) => `'${hash}'`);
+    const type = `export type HashAlgorithm = \n  | ${names.join('\n  | ')};`;
+
+    const nameArray = `[\n  ${names.join(',\n  ')}];`;
+    const constants = `export const hashAlgorithms: t.HashAlgorithm[] = ${nameArray}`;
+    return { type, constants };
+  },
+
+  /**
+   * Generate and save the type definition file.
+   */
+  update() {
+    const header = `
+/**
+ * Generated file - do not edit.
+ * See:
+ *    - generator:  script.ts/generate-hashtype.ts
+ *    - command:    yarn run gen:hashtype
+ */    
+`
+      .substring(1)
+      .slice(0, -1);
+
+    const { type, constants } = HashUnionType.generate();
+    const typeDef = `${header}\n${type}\n`;
+    const importT = `import { type t } from '../common.t';`;
+    const constDef = `${header}\n${importT}\n\n${constants}\n`;
+
+    fs.writeFileSync(fsPath.resolve('./src/types.hashes.ts'), typeDef);
+    fs.writeFileSync(fsPath.resolve('./src/common/const.hashes.ts'), constDef);
+  },
+};
+
+/**
+ * Run
+ */
+HashUnionType.update();
diff --git a/src/FileSystemCache.ts b/src/FileSystemCache.ts
index ef235e8..937a3b4 100644
--- a/src/FileSystemCache.ts
+++ b/src/FileSystemCache.ts
@@ -1,21 +1,23 @@
-import { R, fs, Util } from './common';
-
-export type FileSystemCacheOptions = {
-  basePath?: string;
-  ns?: any;
-  extension?: string;
-  ttl?: number;
-};
+import { R, Util, fs, hashAlgorithms, type t } from './common';
 
 /**
  * A cache that read/writes to a specific part of the file-system.
  */
 export class FileSystemCache {
-  basePath: string;
-  ns?: any;
-  extension?: string;
+  /**
+   * The list of all available hash algorithms.
+   */
+  static hashAlgorithms: t.HashAlgorithm[] = hashAlgorithms;
+
+  /**
+   * Instance.
+   */
+  readonly basePath: string;
+  readonly ns?: any;
+  readonly extension?: string;
+  readonly hash: t.HashAlgorithm;
+  readonly ttl: number;
   basePathExists?: boolean;
-  ttl: number;
 
   /**
    * Constructor.
@@ -28,15 +30,23 @@ export class FileSystemCache {
    *            - extension:  An optional file-extension for paths.
    *            - ttl:        The default time-to-live for cached values in seconds.
    *                          Default: 0 (never expires)
+   *            - hash:       The hashing algorithm to use when generating cache keys.
+   *                          Default: "sha1"
    */
-  constructor(options: FileSystemCacheOptions = {}) {
+  constructor(options: t.FileSystemCacheOptions = {}) {
     this.basePath = formatPath(options.basePath);
-    this.ns = Util.hash(options.ns);
-    this.ttl = typeof options.ttl === 'undefined' ? 0 : options.ttl;
+    this.hash = options.hash ?? 'sha1';
+    this.ns = Util.hash(this.hash, options.ns);
+    this.ttl = options.ttl ?? 0;
     if (Util.isString(options.extension)) this.extension = options.extension;
+
     if (Util.isFileSync(this.basePath)) {
       throw new Error(`The basePath '${this.basePath}' is a file. It should be a folder.`);
     }
+
+    if (!Util.hashExists(this.hash)) {
+      throw new Error(`Hash does not exist: ${this.hash}`);
+    }
   }
 
   /**
@@ -45,7 +55,7 @@ export class FileSystemCache {
    */
   public path(key: string): string {
     if (Util.isNothing(key)) throw new Error(`Path requires a cache key.`);
-    let name = Util.hash(key);
+    let name = Util.hash(this.hash, key);
     if (this.ns) name = `${this.ns}-${name}`;
     if (this.extension) name = `${name}.${this.extension.replace(/^\./, '')}`;
     return `${this.basePath}/${name}`;
diff --git a/src/common.t.ts b/src/common.t.ts
new file mode 100644
index 0000000..1afab57
--- /dev/null
+++ b/src/common.t.ts
@@ -0,0 +1,2 @@
+import type * as t from './types';
+export type { t };
diff --git a/src/common/const.hashes.ts b/src/common/const.hashes.ts
new file mode 100644
index 0000000..d51ca2e
--- /dev/null
+++ b/src/common/const.hashes.ts
@@ -0,0 +1,61 @@
+/**
+ * Generated file - do not edit.
+ * See:
+ *    - generator:  script.ts/generate-hashtype.ts
+ *    - command:    yarn run gen:hashtype
+ */    
+import { type t } from '../common.t';
+
+export const hashAlgorithms: t.HashAlgorithm[] = [
+  'RSA-MD5',
+  'RSA-RIPEMD160',
+  'RSA-SHA1',
+  'RSA-SHA1-2',
+  'RSA-SHA224',
+  'RSA-SHA256',
+  'RSA-SHA3-224',
+  'RSA-SHA3-256',
+  'RSA-SHA3-384',
+  'RSA-SHA3-512',
+  'RSA-SHA384',
+  'RSA-SHA512',
+  'RSA-SHA512/224',
+  'RSA-SHA512/256',
+  'RSA-SM3',
+  'blake2b512',
+  'blake2s256',
+  'id-rsassa-pkcs1-v1_5-with-sha3-224',
+  'id-rsassa-pkcs1-v1_5-with-sha3-256',
+  'id-rsassa-pkcs1-v1_5-with-sha3-384',
+  'id-rsassa-pkcs1-v1_5-with-sha3-512',
+  'md5',
+  'md5-sha1',
+  'md5WithRSAEncryption',
+  'ripemd',
+  'ripemd160',
+  'ripemd160WithRSA',
+  'rmd160',
+  'sha1',
+  'sha1WithRSAEncryption',
+  'sha224',
+  'sha224WithRSAEncryption',
+  'sha256',
+  'sha256WithRSAEncryption',
+  'sha3-224',
+  'sha3-256',
+  'sha3-384',
+  'sha3-512',
+  'sha384',
+  'sha384WithRSAEncryption',
+  'sha512',
+  'sha512-224',
+  'sha512-224WithRSAEncryption',
+  'sha512-256',
+  'sha512-256WithRSAEncryption',
+  'sha512WithRSAEncryption',
+  'shake128',
+  'shake256',
+  'sm3',
+  'sm3WithRSAEncryption',
+  'ssl3-md5',
+  'ssl3-sha1'];
diff --git a/src/common/index.ts b/src/common/index.ts
index 770b333..6eeee58 100644
--- a/src/common/index.ts
+++ b/src/common/index.ts
@@ -1,4 +1,7 @@
-import * as Util from './Util';
+import * as Util from './util';
 
-export { Util };
+export * from './const.hashes';
 export * from './libs';
+export { Util };
+
+export { type t } from '../common.t';
diff --git a/src/common/libs.ts b/src/common/libs.ts
index 9c26e98..3c0a06d 100644
--- a/src/common/libs.ts
+++ b/src/common/libs.ts
@@ -1,6 +1,6 @@
-import R from 'ramda';
+import crypto from 'crypto';
 import fs from 'fs-extra';
 import fsPath from 'path';
-import crypto from 'crypto';
+import R from 'ramda';
 
-export { R, fs, fsPath, crypto };
+export { R, crypto, fs, fsPath };
diff --git a/src/common/Util.ts b/src/common/util.ts
similarity index 89%
rename from src/common/Util.ts
rename to src/common/util.ts
index 112a968..2f3554b 100644
--- a/src/common/Util.ts
+++ b/src/common/util.ts
@@ -1,4 +1,5 @@
-import { R, fs, fsPath, crypto } from './libs';
+import { type t } from '../common.t';
+import { R, crypto, fs, fsPath } from './libs';
 
 export const isNothing = (value: any) => R.isNil(value) || R.isEmpty(value);
 export const isString = R.is(String);
@@ -39,15 +40,19 @@ export const filePathsP = async (basePath: string, ns: string): Promise<string[]
  * Turns a set of values into a HEX hash code.
  * @param values: The set of values to hash.
  */
-export const hash = (...values: any[]) => {
+export const hash = (algorithm: t.HashAlgorithm, ...values: any[]) => {
   if (R.pipe(compact, R.isEmpty)(values)) return undefined;
-  const resultHash = crypto.createHash('sha1');
+  const resultHash = crypto.createHash(algorithm);
   const addValue = (value: any) => resultHash.update(value);
   const addValues = R.forEach(addValue);
   R.pipe(toStringArray, addValues)(values);
   return resultHash.digest('hex');
 };
 
+export const hashExists = (algorithm: t.HashAlgorithm) => {
+  return crypto.getHashes().includes(algorithm);
+};
+
 /**
  * Retrieve a value from the given path.
  */
diff --git a/src/index.ts b/src/index.ts
index 8037aec..87ab277 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,8 @@
-import { FileSystemCache, FileSystemCacheOptions } from './FileSystemCache';
+import { type t } from './common';
+import { FileSystemCache } from './FileSystemCache';
 
 /**
  * Default entry function.
  */
-export default (options?: FileSystemCacheOptions) => new FileSystemCache(options);
-export { FileSystemCache };
+export default (options?: t.FileSystemCacheOptions) => new FileSystemCache(options);
+export { FileSystemCache, FileSystemCache as Cache };
diff --git a/src/test/cache.TEST.ts b/src/test/cache.TEST.ts
index 373a948..a4d7759 100644
--- a/src/test/cache.TEST.ts
+++ b/src/test/cache.TEST.ts
@@ -1,9 +1,25 @@
-import { expect, fs, fsPath, FileSystemCache, Util, basePath } from './common';
+import { FileSystemCache, Util, basePath, expect, fs, fsPath, type t } from './common';
 
-const ABSOLUTE_BASE_PATH = fsPath.resolve(basePath);
+const BASE_PATH = fsPath.resolve(basePath);
 
-describe('FileSystemCache', function () {
-  describe('basePath', function () {
+describe('FileSystemCache', () => {
+  describe('constructor', () => {
+    it('defaults', () => {
+      const cache = new FileSystemCache();
+      expect(cache.hash).to.eql('sha1');
+      expect(cache.ttl).to.eql(0);
+      expect(cache.ns).to.eql(undefined);
+      expect(cache.extension).to.eql(undefined);
+    });
+
+    it('throw: hash not supported', async () => {
+      const hash = '404-no-exist' as any;
+      const fn = () => new FileSystemCache({ hash });
+      expect(fn).to.throw(/Hash does not exist/);
+    });
+  });
+
+  describe('basePath', () => {
     it("has a default path of '/.cache'", () => {
       const cache = new FileSystemCache();
       expect(cache.basePath).to.equal(fsPath.resolve('./.cache'));
@@ -29,7 +45,7 @@ describe('FileSystemCache', function () {
     });
   });
 
-  describe('ns (namespace)', function () {
+  describe('ns (namespace)', () => {
     it('has no namespace by default', () => {
       expect(new FileSystemCache().ns).to.equal(undefined);
       expect(new FileSystemCache([] as any).ns).to.equal(undefined);
@@ -37,50 +53,76 @@ describe('FileSystemCache', function () {
     });
 
     it('creates a namespace hash with a single value', () => {
-      const cache = new FileSystemCache({ ns: 'foo' });
-      expect(cache.ns).to.equal(Util.hash('foo'));
+      const cache1 = new FileSystemCache({ ns: 'foo' });
+      const cache2 = new FileSystemCache({ ns: 'foo', hash: 'sha256' });
+      const cache3 = new FileSystemCache({ ns: 'foo', hash: 'sha512' });
+      expect(cache1.ns).to.equal(Util.hash('sha1', 'foo'));
+      expect(cache2.ns).to.equal(Util.hash('sha256', 'foo'));
+      expect(cache3.ns).to.equal(Util.hash('sha512', 'foo'));
     });
 
     it('creates a namespace hash with several values', () => {
-      const cache = new FileSystemCache({ ns: ['foo', 123] });
-      expect(cache.ns).to.equal(Util.hash('foo', 123));
+      const cache1 = new FileSystemCache({ ns: ['foo', 123] });
+      const cache2 = new FileSystemCache({ ns: ['foo', 123], hash: 'sha256' });
+      const cache3 = new FileSystemCache({ ns: ['foo', 123], hash: 'sha512' });
+      expect(cache1.ns).to.equal(Util.hash('sha1', 'foo', 123));
+      expect(cache2.ns).to.equal(Util.hash('sha256', 'foo', 123));
+      expect(cache3.ns).to.equal(Util.hash('sha512', 'foo', 123));
     });
   });
 
-  describe('path', function () {
+  describe('path', () => {
     it('throws if no key is provided', () => {
       const cache = new FileSystemCache({ basePath });
       expect(() => (cache as any).path()).to.throw();
     });
 
     it('returns a path with no namespace', () => {
-      const key = 'foo';
-      const cache = new FileSystemCache({ basePath });
-      const path = `${ABSOLUTE_BASE_PATH}/${Util.hash(key)}`;
-      expect(cache.path(key)).to.equal(path);
+      const test = (hash: t.HashAlgorithm) => {
+        const key = 'foo';
+        const cache = new FileSystemCache({ basePath, hash });
+        const path = `${BASE_PATH}/${Util.hash(hash, key)}`;
+        expect(cache.path(key)).to.equal(path);
+      };
+
+      test('sha1');
+      test('sha256');
+      test('sha512');
     });
 
     it('returns a path with a namespace', () => {
-      const key = 'foo';
-      const ns = [1, 2];
-      const cache = new FileSystemCache({ basePath, ns: ns });
-      const path = `${ABSOLUTE_BASE_PATH}/${Util.hash(ns)}-${Util.hash(key)}`;
-      expect(cache.path(key)).to.equal(path);
+      const test = (hash: t.HashAlgorithm) => {
+        const key = 'foo';
+        const ns = [1, 2];
+        const cache = new FileSystemCache({ basePath, ns, hash });
+        const path = `${BASE_PATH}/${Util.hash(hash, ns)}-${Util.hash(hash, key)}`;
+        expect(cache.path(key)).to.equal(path);
+      };
+
+      test('sha1');
+      test('sha256');
+      test('sha512');
     });
 
     it('returns a path with a file extension', () => {
-      const key = 'foo';
-      const path = `${ABSOLUTE_BASE_PATH}/${Util.hash(key)}.styl`;
-      let cache;
-      cache = new FileSystemCache({ basePath, extension: 'styl' });
-      expect(cache.path(key)).to.equal(path);
-
-      cache = new FileSystemCache({ basePath, extension: '.styl' });
-      expect(cache.path(key)).to.equal(path);
+      const test = (hash: t.HashAlgorithm) => {
+        const key = 'foo';
+        const path = `${BASE_PATH}/${Util.hash(hash, key)}.styl`;
+        let cache;
+        cache = new FileSystemCache({ basePath, hash, extension: 'styl' });
+        expect(cache.path(key)).to.equal(path);
+
+        cache = new FileSystemCache({ basePath, hash, extension: '.styl' });
+        expect(cache.path(key)).to.equal(path);
+      };
+
+      test('sha1');
+      test('sha256');
+      test('sha512');
     });
   });
 
-  describe('ensureBasePath()', function () {
+  describe('ensureBasePath()', () => {
     it('creates the base path', (done) => {
       const cache = new FileSystemCache({ basePath });
       expect(fs.existsSync(cache.basePath)).to.equal(false);
diff --git a/src/test/cache.expires.TEST.ts b/src/test/cache.expires.TEST.ts
index 029aa1b..7ef3870 100644
--- a/src/test/cache.expires.TEST.ts
+++ b/src/test/cache.expires.TEST.ts
@@ -1,51 +1,47 @@
-import { expect, FileSystemCache, basePath } from './common';
+import { FileSystemCache, basePath, expect } from './common';
 
 function sleep(seconds: number): Promise<void> {
   return new Promise<void>((resolve) => {
     setTimeout(resolve, seconds * 1000);
   });
-} 
+}
 
 describe('expires', async function () {
   this.timeout(3000);
+
   it('cache doesnt expire (various types)', (done) => {
     const cache1 = new FileSystemCache({ basePath, ttl: 10 });
     const cache2 = new FileSystemCache({ basePath, ttl: 10 });
-    
+
     cache1.set('foo-1', 'bar-1');
     cache1.set('foo-2', 'bar-2', 0);
-    cache1.set('foo-3', 'bar-3', 10)
-      .then(() => {
-        cache2.get('foo')
-          .then((result) => { 
-            sleep(1).then(() => { 
-              expect(result).to.equal('bar') 
-            })
-          })
-          .then(() => {
-            cache2.get('foo-2').then((result) => expect(result).to.equal('bar-2'));
-            cache2.get('foo-3').then((result) => expect(result).to.equal('bar-3'));
-          })
-          .finally(() => done());
-      });
-
+    cache1.set('foo-3', 'bar-3', 10).then(() => {
+      cache2
+        .get('foo')
+        .then((result) => {
+          sleep(1).then(() => expect(result).to.equal('bar'));
+        })
+        .then(() => {
+          cache2.get('foo-2').then((result) => expect(result).to.equal('bar-2'));
+          cache2.get('foo-3').then((result) => expect(result).to.equal('bar-3'));
+        })
+        .finally(() => done());
+    });
   });
 
   it('cache expires (various types)', (done) => {
-    const cache1 = new FileSystemCache({ basePath, ttl: 1 });
-    const cache2 = new FileSystemCache({ basePath, ttl: 1 });
-    cache1.set('number', 123)
+    const cache1 = new FileSystemCache({ basePath, ttl: 0.5 });
+    const cache2 = new FileSystemCache({ basePath, ttl: 0.5 });
+    cache1.set('number', 123);
     cache1.set('object', { foo: 456 }, 1).then(() => {
-      sleep(2).then(() => {
-        cache2.get('number')
-          .then((result) => expect(result).to.equal(undefined))
-        cache2.get('object')
+      sleep(1).then(() => {
+        cache2.get('number').then((result) => expect(result).to.equal(undefined));
+        cache2
+          .get('object')
           .then((result) => expect(result).to.equal(undefined))
           .finally(() => done())
-          .catch((err) => console.error(err));;
+          .catch((err) => console.error(err));
       });
     });
   });
-
-
 });
diff --git a/src/test/common.ts b/src/test/common.ts
index 330ceec..bd439f5 100644
--- a/src/test/common.ts
+++ b/src/test/common.ts
@@ -1,9 +1,8 @@
 import { expect } from 'chai';
-import { fs, fsPath, Util } from '../common';
 import { FileSystemCache } from '..';
+import { Util, crypto, fs, fsPath, type t } from '../common';
 
-export { FileSystemCache, fs, fsPath, Util, expect };
-
+export { FileSystemCache, Util, crypto, expect, fs, fsPath, type t };
 export const basePath = './.tmp';
 
 const deleteFolder = () => fs.removeSync(fsPath.resolve(basePath));
diff --git a/src/test/funcs.TEST.ts b/src/test/funcs.TEST.ts
deleted file mode 100644
index f8c7317..0000000
--- a/src/test/funcs.TEST.ts
+++ /dev/null
@@ -1,27 +0,0 @@
-import { expect, Util } from './common';
-
-describe('util.hash', function () {
-  it("does not hash 'nothing' (undefined)", () => {
-    expect(Util.hash()).to.equal(undefined);
-    expect(Util.hash(null)).to.equal(undefined);
-    expect(Util.hash(null, undefined)).to.equal(undefined);
-    expect(Util.hash(null, [undefined, null])).to.equal(undefined);
-  });
-
-  it('returns a hash of multiple values', () => {
-    const result = Util.hash('one', undefined, [3, 4], 2);
-    expect(result).to.equal('0f161cb21daaa15962c1085855fe19dcb9df67e9');
-  });
-
-  it('returns a hash of a single value', () => {
-    const result = Util.hash('one');
-    expect(result).to.equal('443b7f970b6c6af26c392534c0a28ed4ad00a30e');
-  });
-
-  it('returns a hash from an array', () => {
-    const result1 = Util.hash('one', 'two');
-    const result2 = Util.hash(['one', 'two']);
-    expect(result1).to.equal('7fc87660c49692a9b11b02cb23cc478771ca3e3f');
-    expect(result1).to.equal(result2);
-  });
-});
diff --git a/src/test/util.TEST.ts b/src/test/util.TEST.ts
index 4b003db..e3e82d7 100644
--- a/src/test/util.TEST.ts
+++ b/src/test/util.TEST.ts
@@ -1,4 +1,4 @@
-import { expect, Util } from './common';
+import { FileSystemCache, Util, crypto, expect, type t } from './common';
 
 describe('common/util', () => {
   it('compact', () => {
@@ -6,4 +6,52 @@ describe('common/util', () => {
     const res = Util.compact(input);
     expect(res).to.eql(['one', 'two', 'three']);
   });
+
+  describe('util.hash', () => {
+    it("does not hash 'nothing' (undefined)", () => {
+      const test = (algorithm: t.HashAlgorithm) => {
+        expect(Util.hash(algorithm)).to.equal(undefined);
+        expect(Util.hash(algorithm, null)).to.equal(undefined);
+        expect(Util.hash(algorithm, null, undefined)).to.equal(undefined);
+        expect(Util.hash(algorithm, null, [undefined, null])).to.equal(undefined);
+      };
+      FileSystemCache.hashAlgorithms.forEach(test);
+    });
+
+    it('returns a hash of multiple values', () => {
+      const test = (algorithm: t.HashAlgorithm, expected: string) => {
+        const result = Util.hash(algorithm, 'one', undefined, [3, 4], 2);
+        expect(result).to.equal(expected);
+      };
+      test('sha1', '0f161cb21daaa15962c1085855fe19dcb9df67e9');
+      test('sha256', 'c637bf7b330a578cd63a36d1d68c2345959591784dc08d35f249eb596de29c42');
+    });
+
+    it('returns a hash of a single value', () => {
+      const test = (algorithm: t.HashAlgorithm, expected: string) => {
+        const result = Util.hash(algorithm, 'one');
+        expect(result).to.equal(expected);
+      };
+      test('sha1', '443b7f970b6c6af26c392534c0a28ed4ad00a30e');
+      test('sha256', '49e9fcfb5617aad332d56d58ffd0c7020d29ec1d0d0a03b7d7c47f268820acf3');
+    });
+
+    it('returns a hash from an array', () => {
+      const test = (algorithm: t.HashAlgorithm, expected: string) => {
+        const result1 = Util.hash(algorithm, 'one', 'two');
+        const result2 = Util.hash(algorithm, ['one', 'two']);
+        expect(result1).to.equal(expected);
+        expect(result1).to.equal(result2);
+      };
+      test('sha1', '7fc87660c49692a9b11b02cb23cc478771ca3e3f');
+      test('sha256', 'c7d71a7239fceefe30f084ed730d02f609fe63024dc5cf57c674052efedd96ff');
+    });
+  });
+
+  describe('util.hash (generator)', () => {
+    it('hashes constant matches node', () => {
+      const hashes = crypto.getHashes();
+      FileSystemCache.hashAlgorithms.forEach((name) => expect(hashes).to.include(name));
+    });
+  });
 });
diff --git a/src/types.hashes.ts b/src/types.hashes.ts
new file mode 100644
index 0000000..738905e
--- /dev/null
+++ b/src/types.hashes.ts
@@ -0,0 +1,59 @@
+/**
+ * Generated file - do not edit.
+ * See:
+ *    - generator:  script.ts/generate-hashtype.ts
+ *    - command:    yarn run gen:hashtype
+ */    
+export type HashAlgorithm = 
+  | 'RSA-MD5'
+  | 'RSA-RIPEMD160'
+  | 'RSA-SHA1'
+  | 'RSA-SHA1-2'
+  | 'RSA-SHA224'
+  | 'RSA-SHA256'
+  | 'RSA-SHA3-224'
+  | 'RSA-SHA3-256'
+  | 'RSA-SHA3-384'
+  | 'RSA-SHA3-512'
+  | 'RSA-SHA384'
+  | 'RSA-SHA512'
+  | 'RSA-SHA512/224'
+  | 'RSA-SHA512/256'
+  | 'RSA-SM3'
+  | 'blake2b512'
+  | 'blake2s256'
+  | 'id-rsassa-pkcs1-v1_5-with-sha3-224'
+  | 'id-rsassa-pkcs1-v1_5-with-sha3-256'
+  | 'id-rsassa-pkcs1-v1_5-with-sha3-384'
+  | 'id-rsassa-pkcs1-v1_5-with-sha3-512'
+  | 'md5'
+  | 'md5-sha1'
+  | 'md5WithRSAEncryption'
+  | 'ripemd'
+  | 'ripemd160'
+  | 'ripemd160WithRSA'
+  | 'rmd160'
+  | 'sha1'
+  | 'sha1WithRSAEncryption'
+  | 'sha224'
+  | 'sha224WithRSAEncryption'
+  | 'sha256'
+  | 'sha256WithRSAEncryption'
+  | 'sha3-224'
+  | 'sha3-256'
+  | 'sha3-384'
+  | 'sha3-512'
+  | 'sha384'
+  | 'sha384WithRSAEncryption'
+  | 'sha512'
+  | 'sha512-224'
+  | 'sha512-224WithRSAEncryption'
+  | 'sha512-256'
+  | 'sha512-256WithRSAEncryption'
+  | 'sha512WithRSAEncryption'
+  | 'shake128'
+  | 'shake256'
+  | 'sm3'
+  | 'sm3WithRSAEncryption'
+  | 'ssl3-md5'
+  | 'ssl3-sha1';
diff --git a/src/types.ts b/src/types.ts
new file mode 100644
index 0000000..8c2b8da
--- /dev/null
+++ b/src/types.ts
@@ -0,0 +1,10 @@
+import type { HashAlgorithm } from './types.hashes';
+export type { HashAlgorithm };
+
+export type FileSystemCacheOptions = {
+  basePath?: string;
+  ns?: any;
+  ttl?: number;
+  hash?: HashAlgorithm;
+  extension?: string;
+};
diff --git a/yarn.lock b/yarn.lock
index f140a96..18e374b 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -23,6 +23,13 @@
     chalk "^2.0.0"
     js-tokens "^4.0.0"
 
+"@cspotcode/source-map-support@^0.8.0":
+  version "0.8.1"
+  resolved "https://registry.yarnpkg.com/@cspotcode/source-map-support/-/source-map-support-0.8.1.tgz#00629c35a688e05a88b1cda684fb9d5e73f000a1"
+  integrity sha512-IchNf6dN4tHoMFIn/7OE8LWZ19Y6q/67Bmf6vnGREv8RSbBVb9LPJxEcnwrcwX6ixSvaiGoomAUvu4YSxXrVgw==
+  dependencies:
+    "@jridgewell/trace-mapping" "0.3.9"
+
 "@jest/expect-utils@^29.5.0":
   version "29.5.0"
   resolved "https://registry.yarnpkg.com/@jest/expect-utils/-/expect-utils-29.5.0.tgz#f74fad6b6e20f924582dc8ecbf2cb800fe43a036"
@@ -49,15 +56,53 @@
     "@types/yargs" "^17.0.8"
     chalk "^4.0.0"
 
+"@jridgewell/resolve-uri@^3.0.3":
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/@jridgewell/resolve-uri/-/resolve-uri-3.1.1.tgz#c08679063f279615a3326583ba3a90d1d82cc721"
+  integrity sha512-dSYZh7HhCDtCKm4QakX0xFpsRDqjjtZf/kjI/v3T3Nwt5r8/qz/M19F9ySyOqU94SXBmeG9ttTul+YnR4LOxFA==
+
+"@jridgewell/sourcemap-codec@^1.4.10":
+  version "1.4.15"
+  resolved "https://registry.yarnpkg.com/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.4.15.tgz#d7c6e6755c78567a951e04ab52ef0fd26de59f32"
+  integrity sha512-eF2rxCRulEKXHTRiDrDy6erMYWqNw4LPdQ8UQA4huuxaQsVeRPFl2oM8oDGxMFhJUWZf9McpLtJasDDZb/Bpeg==
+
+"@jridgewell/trace-mapping@0.3.9":
+  version "0.3.9"
+  resolved "https://registry.yarnpkg.com/@jridgewell/trace-mapping/-/trace-mapping-0.3.9.tgz#6534fd5933a53ba7cbf3a17615e273a0d1273ff9"
+  integrity sha512-3Belt6tdc8bPgAtbcmdtNJlirVoTmEb5e2gC94PnkwEW9jI6CAHUeoG85tjWP5WquqfavoMtMwiG4P926ZKKuQ==
+  dependencies:
+    "@jridgewell/resolve-uri" "^3.0.3"
+    "@jridgewell/sourcemap-codec" "^1.4.10"
+
 "@sinclair/typebox@^0.25.16":
   version "0.25.24"
   resolved "https://registry.yarnpkg.com/@sinclair/typebox/-/typebox-0.25.24.tgz#8c7688559979f7079aacaf31aa881c3aa410b718"
   integrity sha512-XJfwUVUKDHF5ugKwIcxEgc9k8b7HbznCp6eUfWgu710hMPNIO4aw4/zB5RogDQz8nd6gyCDpU9O/m6qYEWY6yQ==
 
-"@types/chai@4.3.4":
-  version "4.3.4"
-  resolved "https://registry.yarnpkg.com/@types/chai/-/chai-4.3.4.tgz#e913e8175db8307d78b4e8fa690408ba6b65dee4"
-  integrity sha512-KnRanxnpfpjUTqTCXslZSEdLfXExwgNxYPdiO2WGUj8+HDjFi8R3k5RVKPeSCzLjCcshCAtVO2QBbVuAV4kTnw==
+"@tsconfig/node10@^1.0.7":
+  version "1.0.9"
+  resolved "https://registry.yarnpkg.com/@tsconfig/node10/-/node10-1.0.9.tgz#df4907fc07a886922637b15e02d4cebc4c0021b2"
+  integrity sha512-jNsYVVxU8v5g43Erja32laIDHXeoNvFEpX33OK4d6hljo3jDhCBDhx5dhCCTMWUojscpAagGiRkBKxpdl9fxqA==
+
+"@tsconfig/node12@^1.0.7":
+  version "1.0.11"
+  resolved "https://registry.yarnpkg.com/@tsconfig/node12/-/node12-1.0.11.tgz#ee3def1f27d9ed66dac6e46a295cffb0152e058d"
+  integrity sha512-cqefuRsh12pWyGsIoBKJA9luFu3mRxCA+ORZvA4ktLSzIuCUtWVxGIuXigEwO5/ywWFMZ2QEGKWvkZG1zDMTag==
+
+"@tsconfig/node14@^1.0.0":
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/@tsconfig/node14/-/node14-1.0.3.tgz#e4386316284f00b98435bf40f72f75a09dabf6c1"
+  integrity sha512-ysT8mhdixWK6Hw3i1V2AeRqZ5WfXg1G43mqoYlM2nc6388Fq5jcXyr5mRsqViLx/GJYdoL0bfXD8nmF+Zn/Iow==
+
+"@tsconfig/node16@^1.0.2":
+  version "1.0.4"
+  resolved "https://registry.yarnpkg.com/@tsconfig/node16/-/node16-1.0.4.tgz#0b92dcc0cc1c81f6f306a381f28e31b1a56536e9"
+  integrity sha512-vxhUy4J8lyeyinH7Azl1pdd43GJhZH/tP2weN8TntQblOY+A0XbT8DJk1/oCPuOOyg/Ja757rG0CgHcWC8OfMA==
+
+"@types/chai@4.3.5":
+  version "4.3.5"
+  resolved "https://registry.yarnpkg.com/@types/chai/-/chai-4.3.5.tgz#ae69bcbb1bebb68c4ac0b11e9d8ed04526b3562b"
+  integrity sha512-mEo1sAde+UCE6b2hxn332f1g1E8WfYRu6p5SvTKr2ZKC1f7gFJXk4h5PyGP9Dt6gCaG8y8XhwnXWC6Iy2cmBng==
 
 "@types/expect@24.3.0":
   version "24.3.0"
@@ -115,12 +160,12 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-20.2.2.tgz#c2a1383cc392aee13d1eba7082d951df54aed04a"
   integrity sha512-iXqchnHr5CvfO+s/H5/Ji7fNak5bxb2Q2Fadq54sVhXRvEBRZAEyvVs3keVPS0xQNTnhLtxc5QDNXKyzSRpyKA==
 
-"@types/ramda@0.29.1":
-  version "0.29.1"
-  resolved "https://registry.yarnpkg.com/@types/ramda/-/ramda-0.29.1.tgz#c3d3842b9bc4aa5fbe03e90faa0c3eff9ba0f9f4"
-  integrity sha512-Ff5RRG9YRqMgWOqZVVavSjGEvYHUnXnGF0YPGbzIWhB3o8qiccSJZlFX2z8qm3G1H/IC5w0ozHmlezUeQCtGfQ==
+"@types/ramda@0.29.2":
+  version "0.29.2"
+  resolved "https://registry.yarnpkg.com/@types/ramda/-/ramda-0.29.2.tgz#b50d52c3958b0988356bc881bf77aadbd2e33651"
+  integrity sha512-JxvBGR3G4gV3RTOBugVHAAOD6iiv2WjlJ8BHr0s7KALdPpx2l+didoTuoJMmrA0eqpUaCm/slKP4TmxMRihd8g==
   dependencies:
-    types-ramda "^0.29.2"
+    types-ramda "^0.29.3"
 
 "@types/stack-utils@^2.0.0":
   version "2.0.1"
@@ -139,6 +184,16 @@
   dependencies:
     "@types/yargs-parser" "*"
 
+acorn-walk@^8.1.1:
+  version "8.2.0"
+  resolved "https://registry.yarnpkg.com/acorn-walk/-/acorn-walk-8.2.0.tgz#741210f2e2426454508853a2f44d0ab83b7f69c1"
+  integrity sha512-k+iyHEuPgSw6SbuDpGQM+06HQUa04DZ3o+F6CSzXMvvI5KMvnaEqXe+YVe555R9nn6GPt404fos4wcgpw12SDA==
+
+acorn@^8.4.1:
+  version "8.9.0"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.9.0.tgz#78a16e3b2bcc198c10822786fa6679e245db5b59"
+  integrity sha512-jaVNAFBHNLXspO543WnNNPZFRtavh3skAkITqD0/2aeMkKZTN+254PyhwxFYrk3vQ1xfY+2wbesJMs/JC8/PwQ==
+
 ansi-colors@4.1.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/ansi-colors/-/ansi-colors-4.1.1.tgz#cbb9ae256bf750af1eab344f229aa27fe94ba348"
@@ -176,6 +231,11 @@ anymatch@~3.1.2:
     normalize-path "^3.0.0"
     picomatch "^2.0.4"
 
+arg@^4.1.0:
+  version "4.1.3"
+  resolved "https://registry.yarnpkg.com/arg/-/arg-4.1.3.tgz#269fc7ad5b8e42cb63c896d5666017261c144089"
+  integrity sha512-58S9QDqG0Xx27YwPSt9fJxivjYl432YCwfDMfZ+71RAqUrZef7LrKQZ3LHLOwCS4FLNBplP533Zx895SeOCHvA==
+
 argparse@^2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/argparse/-/argparse-2.0.1.tgz#246f50f3ca78a3240f6c997e8a9bd1eac49e4b38"
@@ -331,6 +391,11 @@ concat-map@0.0.1:
   resolved "https://registry.yarnpkg.com/concat-map/-/concat-map-0.0.1.tgz#d8a96bd77fd68df7793a73036a3ba0d5405d477b"
   integrity sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==
 
+create-require@^1.1.0:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/create-require/-/create-require-1.1.1.tgz#c1d7e8f1e5f6cfc9ff65f9cd352d37348756c333"
+  integrity sha512-dcKFX3jn0MpIaXjisoRvexIJVEKzaq7z2rZKxf+MSr9TkdmHmsU4m2lcLojrj/FHl8mk5VxMmYA+ftRkP/3oKQ==
+
 debug@4.3.4:
   version "4.3.4"
   resolved "https://registry.yarnpkg.com/debug/-/debug-4.3.4.tgz#1319f6579357f2338d3337d2cdd4914bb5dcc865"
@@ -365,6 +430,11 @@ diff@^3.1.0:
   resolved "https://registry.yarnpkg.com/diff/-/diff-3.5.0.tgz#800c0dd1e0a8bfbc95835c202ad220fe317e5a12"
   integrity sha512-A46qtFgd+g7pDZinpnwiRJtxbC1hpgf0uzP3iG89scHk0AUC7A1TGxf5OiiOUv/JMZR8GOt8hL900hV0bOy5xA==
 
+diff@^4.0.1:
+  version "4.0.2"
+  resolved "https://registry.yarnpkg.com/diff/-/diff-4.0.2.tgz#60f3aecb89d5fae520c11aa19efc2bb982aade7d"
+  integrity sha512-58lmxKSA4BNyLz+HHMUzlOEpg09FV+ev6ZMe3vJihgdxzgcwZ8VoEEPmALCZG9LmqfVoNMMKpttIYTVG6uDY7A==
+
 emoji-regex@^8.0.0:
   version "8.0.0"
   resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-8.0.0.tgz#e818fd69ce5ccfcb404594f842963bf53164cc37"
@@ -906,6 +976,25 @@ ts-mocha@10.0.0:
   optionalDependencies:
     tsconfig-paths "^3.5.0"
 
+ts-node@10.9.1:
+  version "10.9.1"
+  resolved "https://registry.yarnpkg.com/ts-node/-/ts-node-10.9.1.tgz#e73de9102958af9e1f0b168a6ff320e25adcff4b"
+  integrity sha512-NtVysVPkxxrwFGUUxGYhfux8k78pQB3JqYBXlLRZgdGUqTO5wU/UyHop5p70iEbGhB7q5KmiZiU0Y3KlJrScEw==
+  dependencies:
+    "@cspotcode/source-map-support" "^0.8.0"
+    "@tsconfig/node10" "^1.0.7"
+    "@tsconfig/node12" "^1.0.7"
+    "@tsconfig/node14" "^1.0.0"
+    "@tsconfig/node16" "^1.0.2"
+    acorn "^8.4.1"
+    acorn-walk "^8.1.1"
+    arg "^4.1.0"
+    create-require "^1.1.0"
+    diff "^4.0.1"
+    make-error "^1.1.1"
+    v8-compile-cache-lib "^3.0.1"
+    yn "3.1.1"
+
 ts-node@7.0.1:
   version "7.0.1"
   resolved "https://registry.yarnpkg.com/ts-node/-/ts-node-7.0.1.tgz#9562dc2d1e6d248d24bc55f773e3f614337d9baf"
@@ -940,23 +1029,28 @@ type-detect@^4.0.0, type-detect@^4.0.5:
   resolved "https://registry.yarnpkg.com/type-detect/-/type-detect-4.0.8.tgz#7646fb5f18871cfbb7749e69bd39a6388eb7450c"
   integrity sha512-0fr/mIH1dlO+x7TlcMy+bIDqKPsw/70tVyeHW787goQjhmqaZe10uwLujubK9q9Lg6Fiho1KUKDYz0Z7k7g5/g==
 
-types-ramda@^0.29.2:
-  version "0.29.2"
-  resolved "https://registry.yarnpkg.com/types-ramda/-/types-ramda-0.29.2.tgz#2bf33863a51498b43f616cd8cd98227efe9109eb"
-  integrity sha512-HpLcR0ly2EfXQwG8VSI5ov6ml7PvtT+u+cp+7lZLu7q4nhnPDVW+rUTC1uy/SNs4aAyTUXri5M/LyhgvjEXJDg==
+types-ramda@^0.29.3:
+  version "0.29.3"
+  resolved "https://registry.yarnpkg.com/types-ramda/-/types-ramda-0.29.3.tgz#0a611b4d414bf7c51ba417c3fd3352985b0de97f"
+  integrity sha512-6z8/UCI5/kRorQ91Mo+TUXImHpGAhmhg8ZIdT/tNrG+xSQvDwJXYyT5Nlw2U5VpoKetUZVqQXYYLQyq5Bzccsg==
   dependencies:
     ts-toolbelt "^9.6.0"
 
-typescript@5.0.4:
-  version "5.0.4"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.0.4.tgz#b217fd20119bd61a94d4011274e0ab369058da3b"
-  integrity sha512-cW9T5W9xY37cc+jfEnaUvX91foxtHkza3Nw3wkoF4sSlKn0MONdkdEndig/qPBWXNkmplh3NzayQzCiHM4/hqw==
+typescript@5.1.3:
+  version "5.1.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-5.1.3.tgz#8d84219244a6b40b6fb2b33cc1c062f715b9e826"
+  integrity sha512-XH627E9vkeqhlZFQuL+UsyAXEnibT0kWR2FWONlr4sTjvxyJYnyefgrkyECLzM5NenmKzRAy2rR/OlYLA1HkZw==
 
 universalify@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/universalify/-/universalify-2.0.0.tgz#75a4984efedc4b08975c5aeb73f530d02df25717"
   integrity sha512-hAZsKq7Yy11Zu1DE0OzWjw7nnLZmJZYTDZZyEFHZdUhV8FkH5MCfoU1XMaxXovpyW5nq5scPqq0ZDP9Zyl04oQ==
 
+v8-compile-cache-lib@^3.0.1:
+  version "3.0.1"
+  resolved "https://registry.yarnpkg.com/v8-compile-cache-lib/-/v8-compile-cache-lib-3.0.1.tgz#6336e8d71965cb3d35a1bbb7868445a7c05264bf"
+  integrity sha512-wa7YjyUGfNZngI/vtK0UHAN+lgDCxBPCylVXGp0zu59Fz5aiGtNXaq3DhIov063MorB+VfufLh3JlF2KdTK3xg==
+
 workerpool@6.2.1:
   version "6.2.1"
   resolved "https://registry.yarnpkg.com/workerpool/-/workerpool-6.2.1.tgz#46fc150c17d826b86a008e5a4508656777e9c343"
@@ -1014,6 +1108,11 @@ yargs@16.2.0:
     y18n "^5.0.5"
     yargs-parser "^20.2.2"
 
+yn@3.1.1:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/yn/-/yn-3.1.1.tgz#1e87401a09d767c1d5eab26a6e4c185182d2eb50"
+  integrity sha512-Ux4ygGWsu2c7isFWe8Yu1YluJmqVhxqK2cLXNQA5AcC3QfbGNpM7fu0Y8b/z16pXLnFxZYvWhd3fhBY9DLmC6Q==
+
 yn@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/yn/-/yn-2.0.0.tgz#e5adabc8acf408f6385fc76495684c88e6af689a"