diff --git a/server.js b/server.js
index 31d2885e..4e350e1e 100644
--- a/server.js
+++ b/server.js
@@ -2661,6 +2661,56 @@ ${excerpt}
         }
     }
 
+    // POST /together/share/:shareId/rearchive — AI要約の手動再試行
+    r.post('/together/share/:shareId/rearchive', async (req, res) => {
+        const shareId = parseInt(req.params.shareId, 10);
+        if (Number.isNaN(shareId)) return res.status(400).json({ error: 'invalid shareId' });
+        const username = normalizeTogetherUsername(req.query.u || req.body?.username);
+        const jwtUserId = getTogetherJwtUserId(req);
+        try {
+            const shareRow = await pool.query(
+                'SELECT id, url, full_content, archive_status, summary, group_id FROM together_shares WHERE id=$1',
+                [shareId]
+            );
+            if (shareRow.rows.length === 0) return res.status(404).json({ error: '見つかりません' });
+            const share = shareRow.rows[0];
+            if (!(await togetherEnsureMember(pool, res, share.group_id, username, jwtUserId))) return;
+            if (!checkRateLimit(`rearchive_${shareId}`, 'global', 3, 60 * 60 * 1000)) {
+                return res.status(429).json({ error: '再試行の上限に達しました。1時間後に再試行してください' });
+            }
+            // full_content が既にある（done だが summary なし）場合は Gemini のみ再実行
+            if (share.archive_status === 'done' && share.full_content && !share.summary) {
+                if (!togetherGenAI) return res.status(503).json({ error: 'AI が設定されていません' });
+                await pool.query(`UPDATE together_shares SET archive_status='pending' WHERE id=$1`, [shareId]);
+                res.json({ ok: true, status: 'pending' });
+                try {
+                    const bodyStart = share.full_content.search(/^#{1,2}\s/m);
+                    const excerpt = (bodyStart >= 0 ? share.full_content.slice(bodyStart) : share.full_content).slice(0, 4000);
+                    const model = togetherGenAI.getGenerativeModel({ model: 'gemini-2.5-flash' });
+                    const prompt = `以下の記事を分析して、JSONのみを返してください（コードブロック不要）。\n\n{"summary":"1〜2文の日本語要約","tags":["タグ1","タグ2","タグ3"]}\n\n- summary: 読者が読む価値があるかを判断できる1〜2文\n- tags: 内容を表す具体的な日本語タグを2〜4個。「その他」は絶対に使わないこと\n\n記事:\n${excerpt}`;
+                    const timeoutP = new Promise((_, reject) => setTimeout(() => reject(new Error('timeout')), 30000));
+                    const result = await Promise.race([model.generateContent(prompt), timeoutP]);
+                    const raw = result.response.text().trim();
+                    let summary = null, tags = [];
+                    try { const p = JSON.parse(raw); summary = (p.summary || '').slice(0, 300); tags = Array.isArray(p.tags) ? p.tags.slice(0, 4).map(t => String(t).slice(0, 20)) : []; }
+                    catch { summary = raw.slice(0, 300); }
+                    await pool.query(`UPDATE together_shares SET summary=$1, tags=$2, archive_status='done' WHERE id=$3`, [summary, tags, shareId]);
+                } catch (e) {
+                    console.error('[rearchive gemini]', shareId, e.message);
+                    await pool.query(`UPDATE together_shares SET archive_status='done' WHERE id=$1`, [shareId]);
+                }
+            } else {
+                // failed / skipped — フル再アーカイブ
+                await pool.query(`UPDATE together_shares SET archive_status='pending' WHERE id=$1`, [shareId]);
+                res.json({ ok: true, status: 'pending' });
+                archiveShare(shareId, share.url);
+            }
+        } catch (e) {
+            console.error('[rearchive]', e.message);
+            if (!res.headersSent) res.status(500).json({ error: 'Internal server error' });
+        }
+    });
+
     // POST /together/groups — グループ作成
     r.post('/together/groups', async (req, res) => {
         const { name, username } = req.body || {};