diff --git a/.env.example b/.env.example
index 306146c..01410d2 100644
--- a/.env.example
+++ b/.env.example
@@ -1 +1,6 @@
 TRIANGLES_API_URL=http://127.0.0.1:19112
+
+# JSON-RPC credentials for the /api/verify endpoint (daemon's verifymessage)
+TRIANGLES_RPC_URL=http://127.0.0.1:19112
+TRIANGLES_RPC_USER=trianglesrpc
+TRIANGLES_RPC_PASSWORD=
diff --git a/src/routes/+layout.svelte b/src/routes/+layout.svelte
index 4b7f289..109b875 100644
--- a/src/routes/+layout.svelte
+++ b/src/routes/+layout.svelte
@@ -13,6 +13,7 @@
 		{ href: '/nodes', label: 'Nodes' },
 		{ href: '/richlist', label: 'Rich List' },
 		{ href: '/mempool', label: 'Mempool' },
+		{ href: '/verify', label: 'Verify' },
 		{ href: '/api', label: 'API' }
 	];
 </script>
diff --git a/src/routes/address/[addr]/+page.svelte b/src/routes/address/[addr]/+page.svelte
index 249b2b3..331c626 100644
--- a/src/routes/address/[addr]/+page.svelte
+++ b/src/routes/address/[addr]/+page.svelte
@@ -3,8 +3,20 @@
 	import QRCode from '$lib/components/QRCode.svelte';
 	import { formatAmount, truncateHash, formatNumber } from '$lib/utils';
 
+	// Verified dev contact — populated on 2026-06-23. The signature is
+	// hardcoded and matches the proof published on the project website.
+	// To rotate, generate a new address in TrianglesQt, sign the same
+	// message text, and replace the three fields below.
+	const DEV_CONTACT = {
+		address: 'TRsiRzkMWm87ZuWFwPB8YXFGYr5AQZo7fb',
+		message: 'ROGER THAT, TRIANGLES DEV ADDRESS IS A GO.\n\n5.9.23 IS LIVE.',
+		signature:
+			'H/gT/bFSL+WFT4F4WYPvDIVAnt0/M2WQy/ypUvhMtdXgAop+Euycakif9QERNcUfPLNF29vDxuXZf1BJjd8Snro='
+	};
+
 	let { data } = $props();
-	
+	const isDevContact = data.address === DEV_CONTACT.address;
+
 	// Copy address to clipboard
 	let copied = $state(false);
 	function copyAddress() {
@@ -20,6 +32,40 @@
 	<meta name="description" content="Triangles address {data.address} - balance, transactions, and QR code" />
 </svelte:head>
 
+{#if isDevContact}
+	<!-- Verified Dev Contact badge -->
+	<div class="mb-6 bg-tri-green/10 border-2 border-tri-green/40 rounded-lg p-5">
+		<div class="flex items-center gap-2 mb-2">
+			<span class="text-tri-green text-2xl">✓</span>
+			<h2 class="text-white font-semibold text-lg">Verified Dev Contact</h2>
+		</div>
+		<p class="text-tri-muted text-sm mb-3">
+			This address is cryptographically verified as the official Triangles developer contact address. The
+			signature below was produced by the private key for this address and can be re-verified by anyone
+			using <code class="bg-tri-surface px-1 rounded text-tri-text">trianglesd verifymessage</code> or
+			the <a href="/verify" class="text-tri-accent hover:text-tri-accent-light">/verify</a> tool.
+		</p>
+		<details class="text-sm">
+			<summary class="cursor-pointer text-tri-accent hover:text-tri-accent-light select-none">
+				Show signed message proof
+			</summary>
+			<div class="mt-3 space-y-3">
+				<div>
+					<div class="text-tri-muted text-xs uppercase tracking-wider mb-1">Message</div>
+					<pre
+						class="font-mono text-xs text-tri-text bg-tri-bg/50 border border-tri-border rounded p-2 whitespace-pre-wrap break-all">{DEV_CONTACT.message}</pre>
+				</div>
+				<div>
+					<div class="text-tri-muted text-xs uppercase tracking-wider mb-1">Signature</div>
+					<code
+						class="font-mono text-xs text-tri-text bg-tri-bg/50 border border-tri-border rounded p-2 break-all block"
+					>{DEV_CONTACT.signature}</code>
+				</div>
+			</div>
+		</details>
+	</div>
+{/if}
+
 {#if data.indexError}
 	<div class="mb-6">
 		<h1 class="text-3xl font-bold text-white mb-3">Address Details</h1>
@@ -27,7 +73,7 @@
 			Address index is not enabled on this node. Start the daemon with <code class="bg-tri-surface px-1 rounded">-addressindex=1</code> to enable address lookups.
 		</div>
 	</div>
-	
+
 	<!-- Still show address and QR even if index disabled -->
 	<div class="bg-tri-surface border border-tri-border rounded-lg p-6">
 		<div class="text-center">
@@ -35,7 +81,7 @@
 				<QRCode data={data.address} size={256} />
 			</div>
 			<div class="font-mono text-sm text-tri-text break-all mb-3">{data.address}</div>
-			<button 
+			<button
 				onclick={copyAddress}
 				class="px-4 py-2 bg-tri-accent hover:bg-tri-accent-light text-white rounded transition-colors text-sm font-medium"
 			>
diff --git a/src/routes/api/verify/+server.ts b/src/routes/api/verify/+server.ts
new file mode 100644
index 0000000..04dc50c
--- /dev/null
+++ b/src/routes/api/verify/+server.ts
@@ -0,0 +1,68 @@
+import { json, error } from '@sveltejs/kit';
+import { env } from '$env/dynamic/private';
+import type { RequestHandler } from './$types';
+
+/**
+ * POST /api/verify
+ * Body: { address: string, signature: string, message: string }
+ * Returns: { valid: boolean, error?: string }
+ *
+ * Calls the Triangles daemon's verifymessage via JSON-RPC.
+ */
+export const POST: RequestHandler = async ({ request }) => {
+	let body: { address?: string; signature?: string; message?: string };
+	try {
+		body = await request.json();
+	} catch {
+		error(400, 'Invalid JSON body');
+	}
+
+	const { address, signature, message } = body;
+	if (!address || !signature || !message) {
+		error(400, 'Missing required fields: address, signature, message');
+	}
+
+	const rpcUrl = env.TRIANGLES_RPC_URL || 'http://127.0.0.1:19112';
+	const rpcUser = env.TRIANGLES_RPC_USER || 'trianglesrpc';
+	const rpcPassword = env.TRIANGLES_RPC_PASSWORD || '';
+
+	if (!rpcPassword) {
+		console.error('[api/verify] TRIANGLES_RPC_PASSWORD not set');
+		error(500, 'RPC credentials not configured');
+	}
+
+	const auth = Buffer.from(`${rpcUser}:${rpcPassword}`).toString('base64');
+
+	try {
+		const rpcRes = await fetch(rpcUrl, {
+			method: 'POST',
+			headers: {
+				'Content-Type': 'application/json',
+				Authorization: `Basic ${auth}`
+			},
+			body: JSON.stringify({
+				jsonrpc: '1.0',
+				id: 'verify',
+				method: 'verifymessage',
+				params: [address, signature, message]
+			})
+		});
+
+		// Read body regardless of status — Triangles daemon returns JSON-RPC errors
+		// as HTTP 500 with a valid JSON body.
+		const rpcJson = await rpcRes.json().catch(() => null);
+		if (!rpcJson) {
+			console.error(`[api/verify] RPC HTTP ${rpcRes.status} with non-JSON body`);
+			error(502, `Upstream RPC error: ${rpcRes.status}`);
+		}
+
+		if (rpcJson.error) {
+			return json({ valid: false, error: rpcJson.error.message || String(rpcJson.error) });
+		}
+		return json({ valid: rpcJson.result === true });
+	} catch (e) {
+		const msg = e instanceof Error ? e.message : String(e);
+		console.error(`[api/verify] ${msg}`);
+		error(500, msg);
+	}
+};
diff --git a/src/routes/verify/+page.svelte b/src/routes/verify/+page.svelte
new file mode 100644
index 0000000..879c9d9
--- /dev/null
+++ b/src/routes/verify/+page.svelte
@@ -0,0 +1,158 @@
+<script lang="ts">
+	let address = $state('');
+	let signature = $state('');
+	let message = $state('');
+	let result = $state<{ valid: boolean; error?: string } | null>(null);
+	let loading = $state(false);
+
+	async function verify(e: Event) {
+		e.preventDefault();
+		loading = true;
+		result = null;
+		try {
+			const res = await fetch('/api/verify', {
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({ address, signature, message })
+			});
+			const data = await res.json();
+			result = data;
+		} catch (err) {
+			result = { valid: false, error: err instanceof Error ? err.message : String(err) };
+		} finally {
+			loading = false;
+		}
+	}
+
+	function fillExample() {
+		address = 'TRsiRzkMWm87ZuWFwPB8YXFGYr5AQZo7fb';
+		signature = 'H/gT/bFSL+WFT4F4WYPvDIVAnt0/M2WQy/ypUvhMtdXgAop+Euycakif9QERNcUfPLNF29vDxuXZf1BJjd8Snro=';
+		message = 'ROGER THAT, TRIANGLES DEV ADDRESS IS A GO.\n\n5.9.23 IS LIVE.';
+	}
+</script>
+
+<svelte:head>
+	<title>Verify Signed Message - Triangles Explorer</title>
+	<meta
+		name="description"
+		content="Verify the signature of any Triangles (TRI) signed message. Re-check cryptographic proof of address ownership."
+	/>
+</svelte:head>
+
+<div class="mb-6">
+	<h1 class="text-3xl font-bold text-white mb-2">Verify Signed Message</h1>
+	<p class="text-tri-muted text-sm">
+		Paste a Triangles address, a signed message, and the signature. The explorer will call the daemon's
+		<code class="bg-tri-surface px-1 rounded text-tri-text">verifymessage</code> RPC and report whether the
+		signature is valid for that address and message.
+	</p>
+</div>
+
+<form onsubmit={verify} class="bg-tri-surface border border-tri-border rounded-lg p-6 space-y-4">
+	<div>
+		<label for="addr" class="block text-tri-muted text-xs uppercase tracking-wider mb-2">Address</label>
+		<input
+			id="addr"
+			type="text"
+			bind:value={address}
+			placeholder="TRsiRzkMWm87ZuWFwPB8YXFGYr5AQZo7fb"
+			class="w-full bg-tri-bg border border-tri-border rounded px-3 py-2 text-tri-text font-mono text-sm focus:outline-none focus:border-tri-accent"
+			required
+		/>
+	</div>
+
+	<div>
+		<label for="msg" class="block text-tri-muted text-xs uppercase tracking-wider mb-2">Message</label>
+		<textarea
+			id="msg"
+			bind:value={message}
+			rows="5"
+			placeholder="The exact message that was signed (preserve newlines)"
+			class="w-full bg-tri-bg border border-tri-border rounded px-3 py-2 text-tri-text font-mono text-sm focus:outline-none focus:border-tri-accent whitespace-pre-wrap"
+			required
+		></textarea>
+		<p class="text-tri-muted text-xs mt-1">
+			If your source has literal <code class="bg-tri-bg px-1 rounded">\n</code> characters instead of real
+			newlines, they will be converted automatically.
+		</p>
+	</div>
+
+	<div>
+		<label for="sig" class="block text-tri-muted text-xs uppercase tracking-wider mb-2">Signature</label>
+		<textarea
+			id="sig"
+			bind:value={signature}
+			rows="3"
+			placeholder="Base64-encoded compact ECDSA signature"
+			class="w-full bg-tri-bg border border-tri-border rounded px-3 py-2 text-tri-text font-mono text-xs focus:outline-none focus:border-tri-accent break-all"
+			required
+		></textarea>
+	</div>
+
+	<div class="flex items-center gap-3 pt-2">
+		<button
+			type="submit"
+			disabled={loading}
+			class="px-5 py-2 bg-tri-accent hover:bg-tri-accent-light disabled:bg-tri-muted text-white rounded transition-colors text-sm font-medium"
+		>
+			{loading ? 'Verifying…' : 'Verify Signature'}
+		</button>
+		<button
+			type="button"
+			onclick={fillExample}
+			class="px-4 py-2 bg-tri-border/50 hover:bg-tri-border text-tri-text rounded transition-colors text-sm"
+		>
+			Fill with verified dev contact proof
+		</button>
+	</div>
+</form>
+
+{#if result}
+	<div
+		class="mt-6 rounded-lg p-5 border-2 {result.valid
+			? 'bg-tri-green/10 border-tri-green/40'
+			: 'bg-tri-yellow/10 border-tri-yellow/40'}"
+	>
+		<div class="flex items-center gap-2 mb-2">
+			<span class="text-2xl {result.valid ? 'text-tri-green' : 'text-tri-yellow'}">
+				{result.valid ? '✓' : '✗'}
+			</span>
+			<h2 class="text-white font-semibold text-lg">
+				{result.valid ? 'Signature valid' : 'Signature invalid'}
+			</h2>
+		</div>
+		<p class="text-tri-muted text-sm">
+			{#if result.valid}
+				The signature is cryptographically valid for the provided address and message. The holder
+				of the private key for this address produced the signature.
+			{:else}
+				The signature does <strong>not</strong> match the address + message combination.
+				{#if result.error}
+					<br /><span class="text-tri-yellow">{result.error}</span>
+				{/if}
+			{/if}
+		</p>
+	</div>
+{/if}
+
+<div class="mt-8 bg-tri-surface border border-tri-border rounded-lg p-5 text-sm">
+	<h3 class="text-white font-semibold mb-2">How this works</h3>
+	<ol class="list-decimal list-inside text-tri-muted space-y-1">
+		<li>The browser sends your input to <code class="bg-tri-bg px-1 rounded">/api/verify</code> (server-side).</li>
+		<li>
+			The server calls the Triangles daemon's <code class="bg-tri-bg px-1 rounded"
+				>verifymessage</code
+			>JSON-RPC with the trio.
+		</li>
+		<li>
+			The daemon recovers the public key from the signature, hashes it, and compares to the address's
+			hash. If they match, the signature is valid.
+		</li>
+	</ol>
+	<p class="text-tri-muted text-xs mt-3">
+		You can also run the same check yourself from the command line:<br />
+		<code class="block mt-1 bg-tri-bg p-2 rounded text-tri-text font-mono text-xs break-all">
+			trianglesd verifymessage "&lt;address&gt;" "&lt;signature&gt;" "&lt;message&gt;"
+		</code>
+	</p>
+</div>