diff --git a/docs/master-architecture.md b/docs/master-architecture.md
index a23b87c9..46388611 100644
--- a/docs/master-architecture.md
+++ b/docs/master-architecture.md
@@ -37,6 +37,9 @@
 ║  diff / clean / timer / digest / think / site            ║
 ║  events / maps / tech-events / analytics / roadmap       ║
 ║                                                          ║
+║  【セルフホスト】posimai-dev（Ubuntu PC / Tailscale）     ║
+║  https://ubuntu-pc-pc-mkm21cz79ys4.tail72e846.ts.net:3333║
+║                                                          ║
 ║  【計画中】*.posimai.soar-enrich.com ワイルドカード DNS  ║
 ║  → Passkey の rpID 問題を解決・Eiji に依頼予定           ║
 ╚══════════════════════════════════════════════════════════╝
diff --git a/posimai-dev/index.html b/posimai-dev/index.html
index 8be60cad..fa996ddb 100644
--- a/posimai-dev/index.html
+++ b/posimai-dev/index.html
@@ -36,9 +36,11 @@
         :root {
             --accent: #A78BFA;
             --accent-dim: rgba(167, 139, 250, 0.15);
+            --dev-bg: #0C1221;
         }
         [data-theme="light"] {
             --accent: #7C3AED;
+            --dev-bg: #0C1221;
         }
 
         * { box-sizing: border-box; margin: 0; padding: 0; }
@@ -48,7 +50,7 @@
             flex-direction: column;
             height: 100dvh;
             overflow: hidden;
-            background: var(--bg);
+            background: var(--dev-bg);
         }
 
         .header {
@@ -107,6 +109,10 @@
             overflow: hidden;
             padding: 12px;
             min-height: 0;
+            background:
+                radial-gradient(ellipse at 15% 60%, rgba(34, 211, 238, 0.07) 0%, transparent 55%),
+                radial-gradient(ellipse at 85% 25%, rgba(167, 139, 250, 0.07) 0%, transparent 55%),
+                var(--dev-bg);
         }
 
         #terminal-container .xterm {
@@ -184,8 +190,9 @@
         fontSize: 14,
         lineHeight: 1.4,
         cursorBlink: true,
+        allowTransparency: true,
         theme: {
-            background: '#0D0D0D',
+            background: 'rgba(12, 18, 33, 0.0)',
             foreground: '#F3F4F6',
             cursor: '#A78BFA',
             selectionBackground: 'rgba(167, 139, 250, 0.3)',
diff --git a/posimai-dev/posimai-dev.service b/posimai-dev/posimai-dev.service
new file mode 100644
index 00000000..f54b62f4
--- /dev/null
+++ b/posimai-dev/posimai-dev.service
@@ -0,0 +1,15 @@
+[Unit]
+Description=posimai-dev portal
+After=network.target tailscaled.service
+
+[Service]
+Type=simple
+User=ubuntu-pc
+WorkingDirectory=/home/ubuntu-pc/posimai-project/posimai-dev
+ExecStart=/home/ubuntu-pc/.npm-global/bin/node server.js
+Restart=on-failure
+RestartSec=5
+Environment=PATH=/home/ubuntu-pc/.npm-global/bin:/usr/local/bin:/usr/bin:/bin
+
+[Install]
+WantedBy=multi-user.target
diff --git a/server.js b/server.js
index d902a6d8..7a868c98 100644
--- a/server.js
+++ b/server.js
@@ -2141,6 +2141,154 @@ ${excerpt}
         }
     });
 
+    // ── Atlas: GitHub scan proxy ───────────────────────────────────
+    r.get('/atlas/github-scan', (req, res) => {
+        const token = req.query.token;
+        const org   = req.query.org || '';
+        if (!token) return res.status(400).json({ error: 'token required' });
+
+        const https = require('https');
+
+        function ghRequest(path, cb) {
+            const options = {
+                hostname: 'api.github.com',
+                path,
+                method: 'GET',
+                family: 4,
+                headers: {
+                    Authorization: `Bearer ${token}`,
+                    Accept: 'application/vnd.github+json',
+                    'User-Agent': 'Posimai-Atlas/1.0',
+                    'X-GitHub-Api-Version': '2022-11-28',
+                },
+                timeout: 12000,
+            };
+            const r2 = https.request(options, (resp) => {
+                let body = '';
+                resp.on('data', chunk => { body += chunk; });
+                resp.on('end', () => cb(null, resp.statusCode, body));
+            });
+            r2.on('timeout', () => { r2.destroy(); cb(new Error('Timeout')); });
+            r2.on('error', cb);
+            r2.end();
+        }
+
+        const orgPath  = org ? `/orgs/${encodeURIComponent(org)}/repos?per_page=100&sort=updated` : null;
+        const userPath = `/user/repos?per_page=100&sort=updated&affiliation=owner`;
+
+        function handleResult(status, body) {
+            if (status !== 200) return res.status(status).json({ error: body });
+            try { res.json(JSON.parse(body)); }
+            catch (e) { res.status(500).json({ error: 'Invalid JSON' }); }
+        }
+
+        if (orgPath) {
+            ghRequest(orgPath, (err, status, body) => {
+                if (err) return res.status(500).json({ error: err.message });
+                // If org not accessible, fall back to user repos
+                if (status === 404 || status === 403) {
+                    ghRequest(userPath, (err2, status2, body2) => {
+                        if (err2) return res.status(500).json({ error: err2.message });
+                        // Signal to client that we fell back
+                        if (status2 === 200) {
+                            try {
+                                const data = JSON.parse(body2);
+                                return res.json({ repos: data, fallback: true });
+                            } catch (e) { return res.status(500).json({ error: 'Invalid JSON' }); }
+                        }
+                        handleResult(status2, body2);
+                    });
+                } else {
+                    handleResult(status, body);
+                }
+            });
+        } else {
+            ghRequest(userPath, (err, status, body) => {
+                if (err) return res.status(500).json({ error: err.message });
+                handleResult(status, body);
+            });
+        }
+    });
+
+    // ── Atlas: Vercel scan proxy ───────────────────────────────────
+    r.get('/atlas/vercel-scan', (req, res) => {
+        const token = req.query.token;
+        if (!token) return res.status(400).json({ error: 'token required' });
+
+        const https = require('https');
+        const options = {
+            hostname: 'api.vercel.com',
+            path: '/v9/projects?limit=100',
+            method: 'GET',
+            family: 4,
+            headers: {
+                Authorization: `Bearer ${token}`,
+                'User-Agent': 'Posimai-Atlas/1.0',
+            },
+            timeout: 12000,
+        };
+
+        const req2 = https.request(options, (r2) => {
+            let body = '';
+            r2.on('data', chunk => { body += chunk; });
+            r2.on('end', () => {
+                if (r2.statusCode !== 200) return res.status(r2.statusCode).json({ error: body });
+                try { res.json(JSON.parse(body)); }
+                catch (e) { res.status(500).json({ error: 'Invalid JSON' }); }
+            });
+        });
+        req2.on('timeout', () => { req2.destroy(); res.status(500).json({ error: 'Timeout' }); });
+        req2.on('error', (e) => { res.status(500).json({ error: e.message, code: e.code }); });
+        req2.end();
+    });
+
+    // ── Atlas: Tailscale scan proxy ────────────────────────────────
+    r.get('/atlas/tailscale-scan', (req, res) => {
+        const token = req.query.token;
+        if (!token) return res.status(400).json({ error: 'token required' });
+
+        const https = require('https');
+        const options = {
+            hostname: 'api.tailscale.com',
+            path: '/api/v2/tailnet/-/devices',
+            method: 'GET',
+            family: 4,  // force IPv4; container IPv6 to tailscale times out
+            headers: {
+                Authorization: `Bearer ${token}`,
+                Accept: 'application/json',
+                'User-Agent': 'Posimai-Atlas/1.0',
+            },
+            timeout: 12000,
+        };
+
+        const req2 = https.request(options, (r2) => {
+            let body = '';
+            r2.on('data', chunk => { body += chunk; });
+            r2.on('end', () => {
+                if (r2.statusCode !== 200) {
+                    return res.status(r2.statusCode).json({ error: body });
+                }
+                try {
+                    res.json(JSON.parse(body));
+                } catch (e) {
+                    res.status(500).json({ error: 'Invalid JSON from Tailscale' });
+                }
+            });
+        });
+
+        req2.on('timeout', () => {
+            req2.destroy();
+            res.status(500).json({ error: 'Request timed out' });
+        });
+
+        req2.on('error', (e) => {
+            console.error('[atlas/tailscale-scan] error:', e.code, e.message);
+            res.status(500).json({ error: e.message, code: e.code });
+        });
+
+        req2.end();
+    });
+
     return r;
 }