TCP sockets and TLS - Denoland

:::info Legacy Documentation

You are viewing legacy documentation for Deno Deploy Classic. We recommend migrating to the new <a href="/deploy/">Deno Deploy</a> platform.

:::

Deno Deploy Classic supports outbound TCP and TLS connections. These APIs allow you to use databases like PostgreSQL, SQLite, MongoDB, etc., with Deploy.

Looking for information on serving TCP? Take a look at the documentation for Deno.serve including its support for TCP options.

`Deno.connect`

Make outbound TCP connections.

The function definition is same as Deno with the limitation that transport option can only be tcp and hostname cannot be localhost or empty.

function Deno.connect(options: ConnectOptions): Promise<Conn>

Example

async function handler(_req) {
  // Make a TCP connection to example.com
  const connection = await Deno.connect({
    port: 80,
    hostname: "example.com",
  });

  // Send raw HTTP GET request.
  const request = new TextEncoder().encode(
    "GET / HTTP/1.1\nHost: example.com\r\n\r\n",
  );
  const _bytesWritten = await connection.write(request);

  // Read 15 bytes from the connection.
  const buffer = new Uint8Array(15);
  await connection.read(buffer);
  connection.close();

  // Return the bytes as plain text.
  return new Response(buffer, {
    headers: {
      "content-type": "text/plain;charset=utf-8",
    },
  });
}

Deno.serve(handler);

`Deno.connectTls`

Make outbound TLS connections.

The function definition is the same as Deno with the limitation that hostname cannot be localhost or empty.

function Deno.connectTls(options: ConnectTlsOptions): Promise<Conn>

Example

async function handler(_req) {
  // Make a TLS connection to example.com
  const connection = await Deno.connectTls({
    port: 443,
    hostname: "example.com",
  });

  // Send raw HTTP GET request.
  const request = new TextEncoder().encode(
    "GET / HTTP/1.1\nHost: example.com\r\n\r\n",
  );
  const _bytesWritten = await connection.write(request);

  // Read 15 bytes from the connection.
  const buffer = new Uint8Array(15);
  await connection.read(buffer);
  connection.close();

  // Return the bytes as plain text.
  return new Response(buffer, {
    headers: {
      "content-type": "text/plain;charset=utf-8",
    },
  });
}

Deno.serve(handler);