email: full-text search (FTS5) — backend index + /email/search + search box in the list

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/servers/api/email/email-db.ts

@@ -82,6 +82,7 @@ export function openEmailDb(email: string): Database {
   db.exec(SCHEMA_TABLES);
   migrate(db);
   db.exec(SCHEMA_INDEXES);
+  ensureFts(db);
   // Try to chmod, but don't crash if permission denied (e.g., file owned by different user)
   try {
     chmodSync(dbPath, 0o666);
@@ -119,6 +120,65 @@ function migrate(db: Database): void {
   }
 }
 
+// ── Full-text search (FTS5) ──
+// A standalone FTS5 index kept in sync with `emails` on every upsert. unicode61 + diacritic folding
+// gives accent-insensitive matching; per-term prefix queries make it feel incremental.
+
+function ensureFts(db: Database): void {
+  db.exec(
+    `CREATE VIRTUAL TABLE IF NOT EXISTS emails_fts USING fts5(
+       id UNINDEXED, subject, sender, recipients, snippet, body,
+       tokenize = 'unicode61 remove_diacritics 2'
+     )`,
+  );
+  const fts = (db.query('SELECT count(*) AS c FROM emails_fts').get() as { c: number }).c;
+  const total = (db.query('SELECT count(*) AS c FROM emails').get() as { c: number }).c;
+  if (fts === 0 && total > 0) {
+    // Backfill existing mail (first run after this feature ships).
+    db.exec(
+      `INSERT INTO emails_fts (id, subject, sender, recipients, snippet, body)
+       SELECT id, COALESCE(subject, ''),
+              TRIM(COALESCE(from_name, '') || ' ' || COALESCE(from_address, '')),
+              TRIM(COALESCE(to_address, '') || ' ' || COALESCE(cc, '')),
+              COALESCE(snippet, ''), COALESCE(text_body, '')
+       FROM emails`,
+    );
+  }
+}
+
+const ftsDeleteStmt = 'DELETE FROM emails_fts WHERE id = ?';
+const ftsInsertStmt = 'INSERT INTO emails_fts (id, subject, sender, recipients, snippet, body) VALUES (?, ?, ?, ?, ?, ?)';
+
+function syncFtsRow(db: Database, id: string, subject: string, sender: string, recipients: string, snippet: string, body: string): void {
+  db.run(ftsDeleteStmt, [id]);
+  db.run(ftsInsertStmt, [id, subject, sender, recipients, snippet, body]);
+}
+
+// Per-term prefix match, ANDed. Each term is quoted (so FTS operators in user input are literal) then
+// suffixed with * for prefix matching.
+function toFtsQuery(q: string): string {
+  const terms = q.trim().split(/\s+/).filter(Boolean);
+  return terms.map((t) => `"${t.replace(/"/g, '""')}"*`).join(' ');
+}
+
+export function searchEmails(db: Database, q: string, limit: number, offset: number): { rows: Record<string, unknown>[]; total: number } {
+  const match = toFtsQuery(q);
+  if (!match) return { rows: [], total: 0 };
+  const rows = db
+    .query(
+      `SELECT e.* FROM emails_fts JOIN emails e ON e.id = emails_fts.id
+       WHERE emails_fts MATCH ? AND e.deleted = 0
+       ORDER BY e.date DESC LIMIT ? OFFSET ?`,
+    )
+    .all(match, limit, offset) as Record<string, unknown>[];
+  const total = (
+    db.query('SELECT count(*) AS c FROM emails_fts JOIN emails e ON e.id = emails_fts.id WHERE emails_fts MATCH ? AND e.deleted = 0').get(match) as {
+      c: number;
+    }
+  ).c;
+  return { rows, total };
+}
+
 type ParsedEmail = {
   id: string;
   integration: string;
@@ -173,6 +233,8 @@ export function upsertEmail(db: Database, email: ParsedEmail): void {
       db.run(insertAttachmentStmt, [email.id, i, att.filename, att.size, att.contentType, att.content]);
     }
 
+    syncFtsRow(db, email.id, email.subject ?? '', `${email.fromName ?? ''} ${email.fromAddress ?? ''}`.trim(), `${email.to ?? ''} ${email.cc ?? ''}`.trim(), email.snippet ?? '', email.text ?? '');
+
     db.exec('COMMIT');
   } catch (err) {
     db.exec('ROLLBACK');
@@ -215,6 +277,8 @@ export function upsertFromRawEml({ db, id, raw, integration, emailAccount, label
       db.run(insertAttachmentStmt, [id, i, att.filename, att.size, att.contentType, att.content]);
     }
   }
+
+  syncFtsRow(db, id, subject, `${name} ${address}`.trim(), `${to} ${cc ?? ''}`.trim(), snippet, text ?? '');
 }
 
 /** Convert a db row to an EmailSummary for the API */

src/servers/api/email/email.ts

@@ -3,7 +3,7 @@ import { join } from 'node:path';
 import type { EmailMessage } from 'types';
 import { createRouter } from '../../create-router';
 import { DATA_PATH } from '@@/data-path';
-import { openEmailDb, rowToSummary, getSyncMeta } from './email-db';
+import { openEmailDb, rowToSummary, getSyncMeta, searchEmails } from './email-db';
 import { accountsRouter } from './accounts';
 
 export const emailRouter = createRouter();
@@ -64,6 +64,24 @@ emailRouter.get('/events', (ctx) => {
   });
 });
 
+// Full-text search across all mail (subject / sender / recipients / snippet / body), newest first.
+emailRouter.get('/search', async (ctx) => {
+  const email = ctx.get('user').email;
+  const q = (ctx.req.query('q') ?? '').trim();
+  const page = Math.max(1, Number(ctx.req.query('page') ?? '1') || 1);
+  const limit = Math.min(100, Math.max(1, Number(ctx.req.query('limit') ?? '50') || 50));
+  const offset = (page - 1) * limit;
+  if (!q) return ctx.json({ messages: [], total: 0 });
+
+  const db = openEmailDb(email);
+  try {
+    const { rows, total } = searchEmails(db, q, limit, offset);
+    return ctx.json({ messages: rows.map(rowToSummary), total });
+  } finally {
+    db.close();
+  }
+});
+
 emailRouter.get('/messages', async (ctx) => {
   const email = ctx.get('user').email;
   const page = Number(ctx.req.query('page') ?? '1');