Day3 Website

The public marketing site for Day3: marketing and transactional email, billed by sends. $1/mo.

day3.app

Source-available, not open source. This code is published for transparency and reference. See LICENSE for terms.

What it does

This is the apex-domain site at day3.app. It explains what Day3 is, what it costs, and who it is for. The product itself lives at go.day3.app in its own repo, and the API reference at docs.day3.app in a third.

• Homepage, pricing, how it works, deliverability, security, and the email API pitch
• Feature pages, audience pages (/for/…), and competitor comparisons (/compare/…)
• Blog and changelog, both sourced from typed content modules in src/lib/ rather than a CMS
• Legal surface: terms, privacy, GDPR, DPA, subprocessors, acceptable use
• A Resend pricing calculator at /resend-pricing-calculator
• A beehiiv pricing calculator at /beehiiv-pricing-calculator
• Kit, Mailchimp and MailerLite pricing calculators at /kit-pricing-calculator, /mailchimp-pricing-calculator and /mailerlite-pricing-calculator
• SEO infrastructure: dynamic sitemap, structured data, OG image generation, IndexNow pings, and llms.txt plus llms-full.txt for AI crawlers
• Dogfooding: the newsletter signup popup is a real Day3 signup form, embedded with Day3's own embed.js

Tech stack

Layer	Technology
Framework	Next.js 16 (App Router), React 19, TypeScript
Styling	Tailwind CSS 4, CSS-first @theme tokens in app/globals.css
Components	shadcn/ui on Base UI (@base-ui/react) primitives in src/components/ui/
Icons / fonts	lucide-react, next/font/google (Geist for UI, Instrument Serif for headlines)
Analytics	Google Analytics via @next/third-parties
Hosting	Vercel, apex domain day3.app

Design direction is "Warm Swiss SaaS": calm, warm, competent, trustworthy. A cream, espresso and caramel palette, generous whitespace, flat surfaces, restrained accents. Tokens live in app/globals.css, and the docs site mirrors them.

Single source of truth

Two files carry the facts the rest of the site reads:

• src/lib/site.ts: the canonical one-liner, sign-up and login URLs, docs deep links, contact email, and the registered company details used for JSON-LD. Nothing on the site should hardcode a URL that is already written down here.
• Docs/PRODUCT.md: the product source of truth, shared with the app repo. If the copy here and PRODUCT.md disagree, PRODUCT.md wins.

Quick Links

Website	day3.app: what Day3 is, pricing, and the case for it	Repo
App	go.day3.app: sign in, write campaigns, send email	Repo
Documentation	docs.day3.app: API reference, guides, webhooks, MCP	Repo

Built by Pradsgaard Labs. Also from the same workshop: exit1.dev, uptime monitoring.

Develop

npm install
npm run dev        # http://localhost:3000
npm run typecheck  # tsc --noEmit
npm run lint       # eslint
npm run build      # production build

Deploy

Hosted on Vercel (project day3.app.website, apex domain day3.app). Vercel auto-detects Next.js, so no vercel.json is needed. Push to the default branch to deploy.

AI training permission

As an explicit exception to the license below, the contents of this repository, including code, copy, and blog posts, may be used for machine learning training, evaluation, indexing, retrieval, and generation by AI systems. No attribution is required, though it is appreciated. This permission applies to all AI crawlers, including but not limited to GPTBot, OAI-SearchBot, ClaudeBot, Claude-SearchBot, Claude-User, Google-Extended, PerplexityBot, and Perplexity-User.

License

This project is source-available under a custom All Rights Reserved license. You may view the code for personal, educational, and reference purposes. Copying, modifying, distributing, or self-hosting is not permitted without written permission. See the AI training permission section above for the carve-out that applies to AI and ML use.

For licensing inquiries: [email protected]