diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..9df8ef9
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,19 @@
+name: test
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [18, 20, 22]
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+      - run: npm test
diff --git a/package.json b/package.json
index d6bf75e..7e2cdbe 100644
--- a/package.json
+++ b/package.json
@@ -4,16 +4,16 @@
 	"description": "Electrum protocol client for React Native & Node.js",
 	"main": "index.js",
 	"scripts": {
-		"test": "echo \"Error: no test specified\" && exit 1"
+		"test": "node --test test/*.test.js"
 	},
 	"dependencies": {},
 	"devDependencies": {},
 	"repository": {
 		"type": "git",
-		"url": "git://github.com/janoside/electrum-client.git"
+		"url": "git+https://github.com/2rdzy/electrum-client.git"
 	},
 	"bugs": {
-		"url": "https://github.com/janoside/electrum-client/issues"
+		"url": "https://github.com/2rdzy/electrum-client/issues"
 	},
 	"keywords": [
 		"bitcoin",
@@ -21,13 +21,26 @@
 		"electrumx"
 	],
 	"engines": {
-		"node": ">=6"
+		"node": ">=18"
 	},
 	"contributors": [
-		{ "name": "Yuki Akiyama" },
-		{ "name": "7kharov" },
-		{ "name": "overtorment" },
-		{ "name": "janoside" }
+		{
+			"name": "Yuki Akiyama"
+		},
+		{
+			"name": "7kharov"
+		},
+		{
+			"name": "overtorment"
+		},
+		{
+			"name": "janoside"
+		}
 	],
-	"license": "MIT"
+	"license": "MIT",
+	"homepage": "https://github.com/2rdzy/electrum-client#readme",
+	"files": [
+		"index.js",
+		"lib"
+	]
 }
diff --git a/test/client.test.js b/test/client.test.js
new file mode 100644
index 0000000..36653c9
--- /dev/null
+++ b/test/client.test.js
@@ -0,0 +1,67 @@
+'use strict';
+
+const assert = require('node:assert/strict');
+const { after, before, describe, test } = require('node:test');
+
+const { startServer } = require('./helpers/server.js');
+const { withClient } = require('./helpers/client.js');
+
+const handler = request => {
+	switch (request.method) {
+		case 'server.version': return ['test-server 1.0', '1.4'];
+		case 'echo': return request.params;
+		case 'blockchain.scripthash.get_balance': return { confirmed: request.params[0].length, unconfirmed: 0 };
+		case 'fail': throw { code: 2, message: 'nope' };
+		default: throw { code: -32601, message: `unknown method ${request.method}` };
+	}
+};
+
+for (const [protocol, useTls] of [['tcp', false], ['tls', true]]) {
+	describe(`over ${protocol}`, () => {
+		let server;
+
+		before(async () => { server = await startServer({ useTls, handler }); });
+		after(() => server.close());
+
+		test('negotiates the protocol version', () => withClient(server, protocol, client => {
+			assert.deepEqual(client.versionInfo, ['test-server 1.0', '1.4']);
+		}));
+
+		test('resolves a request with its result', () => withClient(server, protocol, async client => {
+			assert.deepEqual(await client.request('echo', ['a', 1]), ['a', 1]);
+		}));
+
+		test('rejects a request with the server error', () => withClient(server, protocol, async client => {
+			await assert.rejects(client.request('fail', []), { code: 2, message: 'nope' });
+		}));
+
+		test('keeps concurrent requests apart', () => withClient(server, protocol, async client => {
+			const results = await Promise.all([1, 2, 3, 4, 5].map(n => client.request('echo', [n])));
+
+			assert.deepEqual(results, [[1], [2], [3], [4], [5]]);
+		}));
+
+		test('resolves a batch with one entry per parameter, tagged with it', () => withClient(server, protocol, async client => {
+			const results = await client.blockchainScripthash_getBalanceBatch(['aa', 'bbbb', 'cccccc']);
+
+			assert.deepEqual(results.map(r => r.param), ['aa', 'bbbb', 'cccccc']);
+			assert.deepEqual(results.map(r => r.result.confirmed), [2, 4, 6]);
+		}));
+
+		test('emits subscription notifications', () => withClient(server, protocol, async client => {
+			const notified = new Promise(resolve => client.subscribe.once('blockchain.headers.subscribe', resolve));
+
+			server.broadcast(JSON.stringify({ jsonrpc: '2.0', method: 'blockchain.headers.subscribe', params: [{ height: 7 }] }));
+
+			assert.deepEqual(await notified, [{ height: 7 }]);
+		}));
+
+		test('refuses requests after close', async () => {
+			await withClient(server, protocol, async client => {
+				client.close();
+
+				await assert.rejects(client.request('echo', []), /Connection to server lost/);
+			});
+		});
+	});
+}
diff --git a/test/fixtures/cert.pem b/test/fixtures/cert.pem
new file mode 100644
index 0000000..a2ae783
--- /dev/null
+++ b/test/fixtures/cert.pem
@@ -0,0 +1,19 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/test/fixtures/key.pem b/test/fixtures/key.pem
new file mode 100644
index 0000000..03bc7b3
--- /dev/null
+++ b/test/fixtures/key.pem
@@ -0,0 +1,28 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----
diff --git a/test/helpers/client.js b/test/helpers/client.js
new file mode 100644
index 0000000..7b16b53
--- /dev/null
+++ b/test/helpers/client.js
@@ -0,0 +1,23 @@
+'use strict';
+
+// The client expects net and tls to be injected as globals (see lib/client.js).
+global.net = require('net');
+global.tls = require('tls');
+
+const ElectrumClient = require('../../index.js');
+
+// Connect a client to `server`, run `fn(client)`, and always close the client.
+async function withClient(server, protocol, fn, { options, callbacks } = {}) {
+	const client = new ElectrumClient(server.port, '127.0.0.1', protocol, options, callbacks);
+
+	await client.initElectrum({ client: 'electrum-client-test', version: '1.4' }, { retryPeriod: 100000, maxRetry: 0, callback: () => {} });
+
+	try {
+		return await fn(client);
+
+	} finally {
+		client.close();
+	}
+}
+
+module.exports = { ElectrumClient, withClient };
diff --git a/test/helpers/server.js b/test/helpers/server.js
new file mode 100644
index 0000000..fb88787
--- /dev/null
+++ b/test/helpers/server.js
@@ -0,0 +1,76 @@
+'use strict';
+
+// A minimal Electrum-protocol server for tests: newline-delimited JSON-RPC over
+// TCP or TLS. `handler(request)` returns the result for a request, or throws
+// `{code, message}` to send an error.
+
+const fs = require('fs');
+const net = require('net');
+const path = require('path');
+const tls = require('tls');
+
+const fixtures = path.join(__dirname, '..', 'fixtures');
+
+const tlsOptions = {
+	key: fs.readFileSync(path.join(fixtures, 'key.pem')),
+	cert: fs.readFileSync(path.join(fixtures, 'cert.pem')),
+};
+
+function reply(request, handler) {
+	try {
+		return { jsonrpc: '2.0', id: request.id, result: handler(request) };
+
+	} catch (err) {
+		return { jsonrpc: '2.0', id: request.id, error: { code: err.code || -1, message: err.message || String(err) } };
+	}
+}
+
+async function startServer({ useTls = false, handler = req => req.params } = {}) {
+	const sockets = new Set();
+	const received = [];
+
+	const onConnection = socket => {
+		sockets.add(socket);
+		socket.on('close', () => sockets.delete(socket));
+		socket.on('error', () => {});
+		socket.setEncoding('utf8');
+
+		let buffer = '';
+		socket.on('data', chunk => {
+			buffer += chunk;
+
+			let index;
+			while ((index = buffer.indexOf('\n')) !== -1) {
+				const line = buffer.slice(0, index);
+				buffer = buffer.slice(index + 1);
+
+				const message = JSON.parse(line);
+				received.push(message);
+
+				const out = Array.isArray(message)
+					? message.map(request => reply(request, handler))
+					: reply(message, handler);
+
+				socket.write(JSON.stringify(out) + '\n');
+			}
+		});
+	};
+
+	const server = useTls ? tls.createServer(tlsOptions, onConnection) : net.createServer(onConnection);
+
+	await new Promise(resolve => server.listen(0, '127.0.0.1', resolve));
+
+	return {
+		port: server.address().port,
+		received,
+		sockets,
+		// send a raw line to every connected client (for notifications and malformed input)
+		broadcast: line => sockets.forEach(socket => socket.write(line + '\n')),
+		close: () => new Promise(resolve => {
+			sockets.forEach(socket => socket.destroy());
+			server.close(resolve);
+		}),
+	};
+}
+
+module.exports = { startServer, tlsOptions };