Postmint - On-Brand Social Posts in Seconds

A SaaS tool that turns a short description into a polished, on-brand social image — every post grounded in a hand-crafted template and rendered pixel-perfect, so it always looks designed, never random.

Laravel 12 Livewire 3 Tailwind CSS 4 Playwright Anthropic SDK OpenAI Cashier (Stripe) Resend Docker
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Describe It — Postmint Makes It On-Brand

Postmint turns a short description into a polished, on-brand social image in seconds — no designer, no blank canvas, no fiddling with layouts. Save your brand kit once (colors, font, logo), describe a post in plain words, and get a pixel-perfect PNG ready for Instagram or LinkedIn.

The Challenge

Solopreneurs, creators, and small-business owners need to look professional on social media every week — but design is a wall. The tools that exist push in the wrong direction:

  • The blank canvas is intimidating: A design editor hands you an empty artboard and expects you to already know layout, type, and spacing
  • Templates go stale: Generic template libraries produce posts that look like everyone else’s, and adapting them to your brand is manual work every time
  • AI image tools produce slop: Raw generative image models hallucinate text, mangle logos, and output something different every run — unusable for a brand that has to stay consistent
  • A designer is out of reach: Hiring out every post costs an hour and real money for a graphic that’s live for a day

They want an on-brand result, not a design career.

The Solution

Postmint sits between “template gallery” and “raw AI” and takes the best of both. Every post starts from a hand-crafted HTML/CSS template, so layout and type are always correct. A language model writes the copy and fills the template from the user’s brief; the user’s saved brand kit — colors, font, logo — is applied throughout. The composed template is then rendered by a headless browser into a pixel-perfect PNG. The output looks designed because it is designed — the AI supplies words and content decisions, never raw pixels.

Key Features

  • Brand Kit, Set Once: Colors, font, and logo saved once and applied to every post automatically — consistency without re-uploading anything
  • Describe-to-Design: A plain-words brief (“a launch”, “a sale”, “a tip”) becomes finished copy laid into a real template — written and designed in one step
  • Template-Grounded, Never Random: Output is bounded by hand-crafted templates, so it always looks designed — no hallucinated text, no mangled logos, no roll-of-the-dice results
  • Pixel-Perfect Rendering: A Playwright renderer screenshots the composed template into a crisp PNG at exact social dimensions
  • Edit by Chatting: Refine a post conversationally — swap the headline, adjust the emphasis, pull in a stock photo — with no design tools to learn
  • Made for IG & LinkedIn: Formats and framing tuned for the two platforms the audience actually posts to
  • Bilingual: German-first audience, English pages for organic reach — the app works in both

Technical Implementation

Postmint is a two-service architecture: a Laravel SaaS app and a dedicated rendering microservice.

Web Application (Laravel 12 + Livewire 3):

  • Livewire 3 drives the reactive generation and chat-edit flow without a separate API layer
  • The Anthropic SDK and OpenAI client handle copywriting and content decisions from the user brief
  • Brand kits, projects, and generations persisted per user; projects routed by an opaque ULID public_id to keep internal IDs private
  • Tailwind CSS 4 for the mono-mint brand identity

Rendering Service (Node + Playwright):

  • A standalone Node microservice keeps a shared headless browser warm and screenshots composed templates into pixel-perfect PNGs
  • HTML/CSS design templates are the source of visual truth — the AI fills them, it never draws them

Billing & Communications:

  • Laravel Cashier for freemium tiers and subscriptions (Free / Starter / Pro), with per-plan monthly generation limits
  • Fortify for authentication, Resend for transactional and broadcast email with double opt-in
  • Svix for outgoing webhooks, Sentry for error tracking

Deployment:

  • Containerized with Docker and deployed via Dokploy, with a CI pipeline on GitHub Actions

Why It Matters

  • Designed, not generated: Template-grounded output sidesteps the slop problem — every post looks intentional, not like an AI guess
  • On-brand by default: The brand kit is applied to every generation, so consistency is automatic rather than a manual chore
  • Minutes, not an hour: A finished, on-brand post in the time it takes to describe it — the whole point
  • Bilingual & GDPR-ready: German company, DE/EN throughout, freemium with no card required to start