Email system rebuild · 2026-05-19

Branded, locale-aware (FR · EN), table-based HTML email pipeline. Replaces the inline templates that previously lived in a single src/lib/email.ts file.

What changed

New directory src/lib/email/templates/ · one file per template.
New shared layout src/lib/email/templates/base.ts · Sigma navy header with inline SVG logo (Σ wordmark), max-width 640px, mobile media query, factual footer with coverage line, postal address, unsubscribe + copyright.
New helpers src/lib/email/brand.ts (tokens · button · esc), and src/lib/email/locale.ts (inferSignupLocale(req) + normalizeLocale).
Unified sender src/lib/email/send.ts exposes sendTemplate({ to, template, props, locale, userId, kind }). Resolves locale (explicit arg → user.signupLocale → "en"), renders the template, delegates to the legacy sendEmail (nodemailer transport unchanged), persists an EmailEvent row when userId is supplied. Sets a default Reply-To of simon.azoulay.pro@gmail.com (overridable via EMAIL_REPLY_TO).
Schema User.signupLocale String @default("en") (migration 20260519800000_user_signup_locale). Inferred at signup time from the request pathname (/fr/... → "fr"), x-locale header injected by the proxy, referer, or Accept-Language.
Legacy src/lib/email.ts transactional senders now thin-wrap the new template renderers and accept an optional locale argument. Existing daily / weekly / custom-alert renderers stay in place · they already speak FR · EN. All other call sites have been updated to pass the user's signupLocale (or to infer from the request at signup).

Template inventory

File	Purpose	Localised
`src/lib/email/templates/base.ts`	Shared HTML layout (header, footer, mobile media query)	FR · EN
`src/lib/email/templates/welcome.ts`	Welcome (post email-verify)	FR · EN
`src/lib/email/templates/magic-link.ts`	Magic sign-in link (24h)	FR · EN
`src/lib/email/templates/verify.ts`	Email verification (24h)	FR · EN
`src/lib/email/templates/password-reset.ts`	Password reset (1h)	FR · EN
`src/lib/email/templates/upgrade-waitlist.ts`	Upgrade waitlist confirm + follow-up (Pro / Quant)	FR · EN
`src/lib/email/templates/signal-alert.ts`	Single-signal insider buy / sell alert	FR · EN
`src/lib/email/templates/cluster-alert.ts`	Cluster-formation alert (≥3 insiders)	FR · EN
`src/lib/email/templates/watchlist.ts`	Watchlist follow notification	FR · EN
`src/lib/email/templates/delete-confirm.ts`	Account deletion confirmation	FR · EN
`src/lib/email/templates/quota-warning.ts`	Free quota at 80%	FR · EN
`src/lib/email/templates/index.ts`	Public re-export surface	—

Daily digest, weekly digest and custom alert renderers stay in src/lib/email.ts and src/lib/alerts/email.ts · they were already bilingual (or specifically the editorial FR voice for the digests).

Subject lines

Template	EN	FR
welcome	Welcome to InsiderTrades Sigma	Bienvenue sur InsiderTrades Sigma
magic-link	Your sign-in link · expires in 24h	Votre lien de connexion · expire dans 24h
verify	Verify your email · InsiderTrades Sigma	Vérifiez votre adresse · InsiderTrades Sigma
password-reset	Reset your password · InsiderTrades Sigma	Réinitialisation de mot de passe · InsiderTrades Sigma
upgrade-confirm (Pro)	Request received · Pro waitlist · Sigma	Demande reçue · liste d'attente Pro · Sigma
upgrade-confirm (Quant)	Request received · Quant waitlist · Sigma	Demande reçue · liste d'attente Quant · Sigma
upgrade-followup	Still on the Pro list · status update · Sigma	Toujours sur la liste Pro · point d'avancement · Sigma
signal-alert (BUY)	`{insider} just bought {company} ({amount})`	`{insider} vient d'acheter {company} ({amount})`
signal-alert (SELL)	`{insider} just sold {company} ({amount})`	`{insider} vient de céder {company} ({amount})`
cluster-alert	`Cluster forming on {company} ({n} insiders)`	`Cluster en formation sur {company} ({n} dirigeants)`
watchlist	`{n} new signal(s) · {entity}`	`{n} nouveau(x) signa(l
delete-confirm	Account deleted · InsiderTrades Sigma	Compte supprimé · InsiderTrades Sigma
quota-warning	`Free quota at {pct}% · Sigma`	`Quota Free atteint à {pct}% · Sigma`

Locale resolution

explicit `locale` argument
  → user.signupLocale  (DB, set at signup)
  → "en"  (default site language)

At signup (/api/auth/register, /api/auth/register/magic) the locale is inferred by inferSignupLocale(req):

URL pathname prefix (/fr/auth/register → "fr").
x-locale header injected by src/proxy.ts.
referer header (browser usually sends the page the form was on).
First language in Accept-Language.
Default "en".

The resolved value is persisted to User.signupLocale and re-used by all subsequent transactional and alert emails.

Wiring updated

src/app/api/auth/register/route.ts — persists signupLocale, passes it to sendVerificationEmail.
src/app/api/auth/register/magic/route.ts — persists signupLocale, uses new renderMagicLink template (replaces the inline 12-line HTML).
src/app/api/auth/verify/route.ts — reads user.signupLocale, passes to sendWelcomeEmail.
src/app/api/auth/forgot-password/route.ts — reads user.signupLocale, passes to sendPasswordResetEmail.
src/app/api/upgrade-request/route.ts — infers locale from request, passes to confirmation email.
src/app/api/cron/waitlist-followup/route.ts — reads user.signupLocale per row.
src/app/api/cron/alerts-realtime/route.ts — reads user.signupLocale (was hard-coded "fr").
src/app/api/cron/alerts-dispatch/route.ts — same fix.
src/app/api/admin/send-test-email/route.ts — accepts ?locale=fr|en for previewing both languages.

Live test send

Script scripts/test-emails.ts (npm scripts test:emails:dry, test:emails:live) renders + sends every template in both locales to a target inbox.

Run on 2026-05-19 against simon.azoulay.pro@gmail.com:

[test-emails] target=simon.azoulay.pro@gmail.com dry=false only=all
  SENT     EN  welcome                   Welcome to InsiderTrades Sigma
  SENT     FR  welcome                   Bienvenue sur InsiderTrades Sigma
  SENT     EN  magic-link                Your sign-in link · expires in 24h
  SENT     FR  magic-link                Votre lien de connexion · expire dans 24h
  SENT     EN  verify                    Verify your email · InsiderTrades Sigma
  SENT     FR  verify                    Vérifiez votre adresse · InsiderTrades Sigma
  SENT     EN  password-reset            Reset your password · InsiderTrades Sigma
  SENT     FR  password-reset            Réinitialisation de mot de passe · InsiderTrades Sigma
  SENT     EN  upgrade-confirm-pro       Request received · Pro waitlist · Sigma
  SENT     FR  upgrade-confirm-pro       Demande reçue · liste d'attente Pro · Sigma
  SENT     EN  upgrade-confirm-quant     Request received · Quant waitlist · Sigma
  SENT     FR  upgrade-confirm-quant     Demande reçue · liste d'attente Quant · Sigma
  SENT     EN  upgrade-followup          Still on the Pro list · status update · Sigma
  SENT     FR  upgrade-followup          Toujours sur la liste Pro · point d'avancement · Sigma
  SENT     EN  signal-alert-buy          Jean Dupont just bought Société TEST (EUR 1.4M)
  SENT     FR  signal-alert-buy          Jean Dupont vient d'acheter Société TEST (1.4 M EUR)
  SENT     EN  signal-alert-sell         Marie Martin just sold Demo Corp (EUR 3.2M)
  SENT     FR  signal-alert-sell         Marie Martin vient de céder Demo Corp (3.2 M EUR)
  SENT     EN  cluster-alert             Cluster forming on Cluster Test SA (5 insiders)
  SENT     FR  cluster-alert             Cluster en formation sur Cluster Test SA (5 dirigeants)
  SENT     EN  watchlist                 3 new signals · LVMH
  SENT     FR  watchlist                 3 nouveaux signaux · LVMH
  SENT     EN  delete-confirm            Account deleted · InsiderTrades Sigma
  SENT     FR  delete-confirm            Compte supprimé · InsiderTrades Sigma
  SENT     EN  quota-warning             Free quota at 80% · Sigma
  SENT     FR  quota-warning             Quota Free atteint à 80% · Sigma
[test-emails] done · 26/26 ok · 0 failed · 45.5s

26 of 26 sends OK (13 templates × 2 locales). All delivered, all rendered with the same navy header, inline Σ SVG, gold CTA, mobile media query, factual footer.

Validation

npm run lint:emdash → OK, no em-dashes in user-facing copy.
npm run lint:emoji → OK, 449 files scanned, no disallowed emoji.
npm run typecheck → OK, no errors.
npm run build → OK.
npx prisma migrate deploy → 2 migration(s) deployed (signup locale + earlier insider-name index).

Constraints honored

NO em-dashes anywhere · middle-dot (·) used as separator.
NO emoji · CSS dots, → and inline SVG only.
Inline CSS throughout (Outlook · Gmail compat).
Table-based layout, max 640px wide, single media query for mobile.
Logo is pure inline SVG (no external image, no privacy leak, no spam filter trigger).
FR uses vouvoiement throughout.
Reply-To header always set, defaults to simon.azoulay.pro@gmail.com.