Workers VPC - TCP connections via connect() over VPC Networks

<p><a href="https://developers.cloudflare.com/workers-vpc/configuration/vpc-networks/">VPC Network</a> bindings now support the <a href="https://developers.cloudflare.com/workers/runtime-apis/tcp-sockets/"><code>connect()</code></a> Socket API for raw TCP connections to private destinations, in addition to HTTP traffic via <code>fetch()</code>.</p> <p>This means Workers can now open TCP sockets to any private service reachable through the bound Cloudflare Tunnel, Cloudflare Mesh, or Cloudflare WAN on-ramp — Redis, Memcached, MQTT, custom binary protocols, or any other TCP-based service.</p> <div data-nb-tabs data-nb-sync-key="wranglerConfig" class><div class="relative flex border-b border-border" role="tablist" data-nb-tabs-list><span class="bg-primary pointer-events-none absolute -bottom-px h-0.5 rounded-t-sm transition-[left,width] duration-200 ease-out" data-nb-tabs-indicator aria-hidden="true"></span></div><div class="mt-3"><div role="tabpanel" data-nb-tabs-content data-nb-tab-label="wrangler.jsonc" class><figure class="nb-code-figure" data-nb-lang="jsonc"><pre class="astro-code astro-code-themes github-light github-dark nb-shiki-c6xiwz" tabindex="0" data-language="jsonc" data-nb-lang="jsonc"><code><span class="line"><span class="nb-shiki-140thh">{</span></span> <span class="line"><span class="nb-shiki-dzsirb"> "$schema"</span><span class="nb-shiki-140thh">: </span><span class="nb-shiki-mdbnqw">"./node_modules/wrangler/config-schema.json"</span><span class="nb-shiki-140thh">,</span></span> <span class="line"><span class="nb-shiki-dzsirb"> "vpc_networks"</span><span class="nb-shiki-140thh">: [</span></span> <span class="line"><span class="nb-shiki-140thh"> {</span></span> <span class="line"><span class="nb-shiki-dzsirb"> "binding"</span><span class="nb-shiki-140thh">: </span><span class="nb-shiki-mdbnqw">"PRIVATE_NETWORK"</span><span class="nb-shiki-140thh">,</span></span> <span class="line"><span class="nb-shiki-dzsirb"> "network_id"</span><span class="nb-shiki-140thh">: </span><span class="nb-shiki-mdbnqw">"cf1:network"</span><span class="nb-shiki-140thh">,</span></span> <span class="line"><span class="nb-shiki-dzsirb"> "remote"</span><span class="nb-shiki-140thh">: </span><span class="nb-shiki-dzsirb">true</span></span> <span class="line"><span class="nb-shiki-140thh"> }</span></span> <span class="line"><span class="nb-shiki-140thh"> ]</span></span> <span class="line"><span class="nb-shiki-140thh">}</span></span></code></pre></figure></div><div role="tabpanel" data-nb-tabs-content data-nb-tab-label="wrangler.toml" class><figure class="nb-code-figure" data-nb-lang="toml"><pre class="astro-code astro-code-themes github-light github-dark nb-shiki-c6xiwz" tabindex="0" data-language="toml" data-nb-lang="toml"><code><span class="line"><span class="nb-shiki-140thh">[[</span><span class="nb-shiki-1t8gfj">vpc_networks</span><span class="nb-shiki-140thh">]]</span></span> <span class="line"><span class="nb-shiki-140thh">binding = </span><span class="nb-shiki-mdbnqw">"PRIVATE_NETWORK"</span></span> <span class="line"><span class="nb-shiki-140thh">network_id = </span><span class="nb-shiki-mdbnqw">"cf1:network"</span></span> <span class="line"><span class="nb-shiki-140thh">remote = </span><span class="nb-shiki-dzsirb">true</span></span></code></pre></figure></div></div></div><script type="module" src="https://developers.cloudflare.com/home/runner/work/cloudflare-docs/cloudflare-docs/src/components/ui/tabs/Tabs.astro?astro&type=script&index=0&lang.ts"></script> <p>At runtime, use <code>connect()</code> on the binding to open a TCP socket to a private destination:</p> <figure class="nb-code-figure" data-nb-lang="ts"><pre class="astro-code astro-code-themes github-light github-dark nb-shiki-c6xiwz" tabindex="0" data-language="ts" data-nb-lang="ts"><code><span class="line"><span class="nb-shiki-1itgoe">export</span><span class="nb-shiki-1itgoe"> default</span><span class="nb-shiki-140thh"> {</span></span> <span class="line"><span class="nb-shiki-1itgoe"> async</span><span class="nb-shiki-1t8gfj"> fetch</span><span class="nb-shiki-140thh">(</span><span class="nb-shiki-1jdh33">request</span><span class="nb-shiki-1itgoe">:</span><span class="nb-shiki-1t8gfj"> Request</span><span class="nb-shiki-140thh">, </span><span class="nb-shiki-1jdh33">env</span><span class="nb-shiki-1itgoe">:</span><span class="nb-shiki-1t8gfj"> Env</span><span class="nb-shiki-140thh">) {</span></span> <span class="line"><span class="nb-shiki-21nrsd"> // Open a TCP connection to a private Redis instance</span></span> <span class="line"><span class="nb-shiki-1itgoe"> const</span><span class="nb-shiki-dzsirb"> socket</span><span class="nb-shiki-1itgoe"> =</span><span class="nb-shiki-1itgoe"> await</span><span class="nb-shiki-140thh"> env.</span><span class="nb-shiki-dzsirb">PRIVATE_NETWORK</span><span class="nb-shiki-140thh">.</span><span class="nb-shiki-1t8gfj">connect</span><span class="nb-shiki-140thh">(</span><span class="nb-shiki-mdbnqw">"10.0.1.50:6379"</span><span class="nb-shiki-140thh">);</span></span> <span class="line"></span> <span class="line"><span class="nb-shiki-21nrsd"> // Write a Redis PING command</span></span> <span class="line"><span class="nb-shiki-1itgoe"> const</span><span class="nb-shiki-dzsirb"> writer</span><span class="nb-shiki-1itgoe"> =</span><span class="nb-shiki-140thh"> socket.writable.</span><span class="nb-shiki-1t8gfj">getWriter</span><span class="nb-shiki-140thh">();</span></span> <span class="line"><span class="nb-shiki-1itgoe"> await</span><span class="nb-shiki-140thh"> writer.</span><span class="nb-shiki-1t8gfj">write</span><span class="nb-shiki-140thh">(</span><span class="nb-shiki-1itgoe">new</span><span class="nb-shiki-1t8gfj"> TextEncoder</span><span class="nb-shiki-140thh">().</span><span class="nb-shiki-1t8gfj">encode</span><span class="nb-shiki-140thh">(</span><span class="nb-shiki-mdbnqw">"PING</span><span class="nb-shiki-dzsirb">\r\n</span><span class="nb-shiki-mdbnqw">"</span><span class="nb-shiki-140thh">));</span></span> <span class="line"><span class="nb-shiki-1itgoe"> await</span><span class="nb-shiki-140thh"> writer.</span><span class="nb-shiki-1t8gfj">close</span><span class="nb-shiki-140thh">();</span></span> <span class="line"></span> <span class="line"><span class="nb-shiki-1itgoe"> return</span><span class="nb-shiki-1itgoe"> new</span><span class="nb-shiki-1t8gfj"> Response</span><span class="nb-shiki-140thh">(socket.readable);</span></span> <span class="line"><span class="nb-shiki-140thh"> },</span></span> <span class="line"><span class="nb-shiki-140thh">};</span></span></code></pre></figure> <aside role="note" aria-label="Note" class="aside-card flex items-start gap-3 rounded-lg px-4 py-3 my-4" style="--_c: var(--nb-info); --_t: var(--nb-info-muted);" data-astro-cid-znle5jil><span class="flex h-[1.375em] shrink-0 items-center" aria-hidden="true" data-astro-cid-znle5jil><svg width="1em" height="1em" viewBox="0 0 256 256" class="h-[1em] w-[1em]" data-astro-cid-znle5jil="true" data-icon="ph:info"><path fill="currentColor" d="M128 24a104 104 0 1 0 104 104A104.11 104.11 0 0 0 128 24m0 192a88 88 0 1 1 88-88a88.1 88.1 0 0 1-88 88m16-40a8 8 0 0 1-8 8a16 16 0 0 1-16-16v-40a8 8 0 0 1 0-16a16 16 0 0 1 16 16v40a8 8 0 0 1 8 8m-32-92a12 12 0 1 1 12 12a12 12 0 0 1-12-12"/></svg></span><div class="flex min-w-0 flex-1 flex-col gap-0.5" data-astro-cid-znle5jil><p class="m-0 text-base leading-snug font-semibold" data-astro-cid-znle5jil>Note</p><div class="aside-card-body text-sm leading-normal" data-astro-cid-znle5jil><p><code>connect()</code> over VPC Networks currently supports plaintext TCP only.</p></div></div></aside> <p>For more details, refer to <a href="https://developers.cloudflare.com/workers-vpc/configuration/vpc-networks/">VPC Networks</a> and the <a href="https://developers.cloudflare.com/workers-vpc/api/">Workers Binding API</a>.</p>