Prototype Executor

Agent Overview

Role: Selects the optimal build approach (full-stack coded, no-code, or hybrid), generates a working MVP with authentication, payment processing, and analytics, then deploys to production with error monitoring — delivering a live, testable product.

Type: executor

Phase: 7B (Measurement & Prototype) — can run anytime after Phase 4B

Trigger: Validation Report from Phase 2.5 confirms product-market fit signal AND Brand Strategy from Phase 4A provides visual direction

Input → Output Summary

INPUTS:                          OUTPUTS:
+-----------------------+        +------------------------------+
| Startup Brief         |---+    | Deployed MVP                 |---> Scale Architect
| (features, model,     |   |    | (live URL, auth, payments,   |---> Dashboard
|  value prop)          |   |    |  analytics, monitoring)       |
+-----------------------+   |    +------------------------------+
| Validation Report     |---+--> | Technical Architecture Doc   |---> Scale Architect
| (validated features,  |   |    | (stack, schema, APIs, auth,  |---> Dashboard
|  priorities, PMF)     |   |    |  payment, deploy config)     |
+-----------------------+   |    +------------------------------+
| Brand Strategy        |---+    | MVP Metrics Dashboard Config |---> KPI Architect
| (colors, typography,  |        | (events, funnels, alerts)    |     Dashboard
|  logo, tone)          |        +------------------------------+
+-----------------------+
| Financial Model       |---*
| (pricing, tiers)      |
| (optional)            |
+-----------------------+

Key Deliverables

• Deployed MVP — live, publicly accessible application with working auth, payment processing, analytics, and error monitoring. Includes production URL, staging URL, and admin credentials.
• Technical Architecture Document — complete tech stack with rationale, database schema, API routes, auth and payment flow diagrams, environment variables, deployment config, known limitations, and scaling notes.
• MVP Metrics Dashboard Config — tracked events taxonomy, conversion funnel definition, key metric targets (DAU, activation rate, trial-to-paid, churn), and alert configuration.

Execution Pipeline

1. Select Build Approach — evaluate product requirements against full-stack coded, no-code (Bubble, Webflow), hybrid, or AI app builder (Bolt, Lovable, Replit) approaches
2. Select Tech Stack — choose frontend (Next.js 15, SvelteKit), backend (API Routes, Express), database (Supabase, Neon), ORM (Prisma, Drizzle)
3. Set Up Project Structure — initialize repo, apply brand colors/fonts/logo from Brand Strategy to Tailwind config and layout
4. Implement Auth — Clerk (best DX, 5-10 min), Supabase Auth (if using Supabase DB), or Auth0 (enterprise SSO). Sign-up, sign-in, password reset, social login, route protection.
5. Implement Payments — Stripe Checkout for one-time or subscription billing, webhook handler for payment confirmation, Customer Portal for self-service management
6. Build Core Features — implement only must-have features from Validation Report, onboarding flow, settings/account management
7. Set Up Database — schema design with UUIDs, indexes, timestamps, RLS policies, seed data, migration workflow
8. Integrate Analytics — PostHog (default: analytics + replay + flags), track 10+ events including sign_up, activation, checkout, payment, churn
9. Set Up Error Monitoring — Sentry integration with source maps, alert rules, error boundaries, user context
10. Deploy to Production — Vercel (default for Next.js), environment variables, custom domain, SSL, post-deploy verification
11. Security & Performance — CSP headers, HSTS, rate limiting, image optimization, Core Web Vitals targeting, GDPR compliance if EU users
12. Quality Self-Check — verify all systems working end-to-end before delivery

Gate Conditions

Before: Validation Report from Phase 2.5 confirms product-market fit signal; Brand Strategy from Phase 4A provides visual direction.

After: MVP deployed and accessible, auth working, payment processing tested, analytics sending data.

Default Tech Stack

Hard Constraints

• NEVER commit secrets to git — use .env.local and platform environment variables
• NEVER go to production with Stripe test keys when accepting real payments
• NEVER skip email verification before granting paid feature access
• NEVER fulfill payments based on redirect URL alone — always use Stripe webhooks
• NEVER store raw payment data (card numbers, CVVs) — use Stripe Checkout or Elements
• NEVER deploy without error monitoring (Sentry)
• ALWAYS verify auth sessions server-side on protected routes
• ALWAYS use HTTPS in production
• ALWAYS build mobile-responsive (60%+ of startup traffic is mobile)
• ALWAYS include account deletion (GDPR, Apple App Store requirement)

When This Matters

Invoke after Phase 4B (Brand Strategy complete) when Phase 2.5 (Customer Validation) has confirmed product-market fit. This is the agent that turns strategy and validation into a live product. The Scale Architect (Phase 8) needs the deployed MVP and architecture document to plan infrastructure scaling. The KPI Architect needs the metrics dashboard configuration. Without a deployed, instrumented MVP, both downstream agents stall and the startup cannot begin measuring real user behavior.