Case Study
Promptello — a Figma-meets-Notion for AI prompts, with a built-in marketplace so creators can monetise the ones that win.
How we designed and shipped Promptello — a voice-first prompt engineering workstation that interviews the user, routes to the best model automatically, versions every refinement, and lets creators sell premium prompts inside a built-in marketplace.
3 models
Auto-routed (Claude, Gemini, GPT)
10 free
Trial prompts, no signup
15%
Platform fee on marketplace sales
The challenge
Creators were wrestling AI models instead of getting value out of them
Modern creators, marketers and developers spend more time wrestling with AI models than getting value out of them. The same prompts get retyped across ChatGPT, Claude, Gemini and Midjourney, quality drifts between models, there is no version history, and nobody owns the intellectual property of prompts they iterate on for weeks.
Promptello had to solve four problems at once: capture intent quickly (including by voice), interrogate the user like a senior copywriter would, generate a model-tuned prompt against the best-fit model automatically, and preserve every refinement as versioned, sellable IP.
How it works
Inside the build
01
Phase 1 — Intent Capture Studio
Dual-mode input: a rich textarea plus a Web Speech API dictation flow with an optional full-screen cinematic Dialogue Screen for voice-first drafting. Image attachments can be referenced as visual context. The blank-page problem disappears.
02
Phase 2 — Adaptive Interview Engine
After capture, Promptello asks three to five category-aware follow-ups (tone, audience, constraints, format) driven by a per-category JSON schema and validated with Zod. The app refuses to answer until it understands the brief.
03
Phase 3 — Model-aware generation with an Auto router
Users pick Claude Sonnet, Gemini or GPT — or select Auto, which evaluates the intent and routes to the best-fit model via the Lovable AI Gateway. A live ModelPill shows which brain answered, so trust is built in.
04
Phase 4 — Versioned Prompt Library
Every refinement writes a new immutable version to Postgres with full history and diffs. Folders, tags, categories, favourites and archive states are first-class. Row-Level Security enforces multi-tenancy at the database, not in app code.
05
Phase 5 — Brands, Projects and Variables
Reusable brand profiles (tone, audience, style guardrails) attach to projects so every generated prompt inherits voice automatically. A syntax-aware editor detects {{variables}} in real time so prompts become parameterised templates, not one-off text blobs.
06
Phase 6 — Marketplace & Monetisation
Any prompt can be flagged premium with a price. A dashboard tracks sales, subscribers and per-prompt performance. Promptello takes a 15% platform fee — competitive against Gumroad's 10% and prompt-specific marketplaces charging 20–30%.
In action
See the app in action
Benefits
What the business actually gains
Voice-first drafting
Web Speech API dictation with a cinematic Dialogue Screen — creators talk out a week of content in minutes instead of typing it.
Auto model routing
One click sends the brief to the best-fit model across Claude, Gemini and GPT. No more anxiety about which model to use for which job.
Every prompt is versioned IP
Git-style history for prompts. Nothing is ever lost, every refinement is diffable, and creators finally own their prompt library like a codebase.
Brand voice, cloned once
Reusable brand profiles inject tone, audience and style into every generation. Agencies and multi-brand creators stop pasting the same preamble everywhere.
Marketplace revenue on day one
Subscribers can flag any prompt premium, set a price and sell it. Passive income from prompts creators were writing anyway.
Try before signup
Ten free prompts, tracked in localStorage, before an auth wall ever appears. Trust-first funnel that outperforms the industry norm.
Features
Everything the platform delivers
- Dual-mode intent capture (typed + Web Speech API dictation) with full-screen Dialogue Screen
- Adaptive interview engine with category-aware JSON schemas validated by Zod
- Auto model router across Claude Sonnet, Gemini 2.5 and GPT via the Lovable AI Gateway
- Immutable versioned prompt library with folders, tags, favourites, archives and diffs
- Reusable brand profiles that inject tone, audience and style into every generation
- Live prompt editor with {{variable}} highlighting, debounced autosave and publish toggle
- Multi-format export to Markdown, JSON and public share links
- Global ⌘K command palette for fuzzy search across prompts, projects and brands
- Monetisation dashboard: sales, subscribers, per-prompt performance and earnings widget
- Usage dashboard, guided first-run tour and mobile-first bottom tab bar
Technology
Built on a modern stack
Why it matters
This is what bespoke automation looks like
Three lessons from shipping a multi-model creator product.
1. The model is a detail, the workflow is the product. The moment users stopped picking models and let Auto route, engagement jumped. The interesting surface is the interview, the versioning and the library — not which LLM answered.
2. Prompts are intellectual property. Treating them as versioned, ownable, sellable assets — instead of throwaway text — is what unlocks a creator economy on top of any AI tool.
3. A trust-first funnel beats a signup wall. Ten free prompts with no email required converts better than a locked hero. Value has to be provable before a card is asked for.
"Promptello turned my prompt library into an asset. I dictate an idea, the app interviews me, and a week later I'm selling the winning prompt to other creators — from the same workstation I drafted it in."
— Beta creator, Promptello early access
Services used
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FAQ
Frequently asked questions
Who is Promptello for?
Content creators, marketers, developers and agencies who use multiple AI models weekly and want a single workstation to draft, version, template and monetise their prompts.
How does the Auto model router decide?
The router evaluates the captured intent (task type, length, constraints, whether images are attached) and picks the best-fit model via the Lovable AI Gateway. A ModelPill on the response shows which model answered so the user can override for future runs.
How does the marketplace payout work?
Subscribers flag any prompt as premium and set a price. Promptello takes a 15% platform fee and remits the rest — competitive against Gumroad's 10% and prompt-specific marketplaces charging 20–30%.
Is the prompt data private?
Yes. Every user's prompts, versions, brands and projects sit behind Postgres Row-Level Security policies enforced at the database, not in application code. Only prompts explicitly flagged premium and published are visible to buyers.
Could you build something similar for our team?
Yes. The same pattern — capture, interview, multi-model routing, versioned library, marketplace layer — transfers to internal knowledge tools, agency deliverables and vertical AI products. Book a call and we'll scope it.
Ready to automate your business?
This is just one example of what's possible. If you have a repetitive process costing you time, we can build a custom tool to handle it.
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