Full-stack developer — SMS AI bot with Stripe subscriptions & admin dashboard OVERVIEW I'm building a two-way SMS service where users text a phone number, their message is sent to an AI API, and the AI's response is sent back via SMS. I have a detailed technical specification ready to share. This is a well-scoped, clean build — the stack is already decided, the architecture is defined, and the AI layer is handled entirely by me. Your job is everything around the AI: SMS infrastructure, freemium subscription system, admin dashboard, and handoff training so I can operate it independently. REQUIRED STACK — NO SUBSTITUTIONS - Language: Node.js - SMS: Twilio - Payments: Stripe - Database: PostgreSQL - Framework: Express.js - Hosting: Railway WHAT YOU'LL BUILD - Twilio SMS webhook — receive inbound messages, call AI API, return response - SMS-native onboarding — state machine that collects one user preference (single-digit selection from 3 options) before activating the main loop - Freemium tier — free users get 10 messages/month; paid users get unlimited - Stripe — Checkout, Customer Portal, subscription webhooks, payment failure handling and downgrade logic - PostgreSQL on Railway — user records, preferences, subscription state, monthly message counts - Admin dashboard — user list, tier overrides, message logs, usage summary, Stripe sync status, broadcast SMS - Keyword commands — STOP, HELP, RESET, UPGRADE, STATUS - Graceful error handling and fallback SMS throughout AI INTEGRATION The AI logic is owned entirely by me. Your integration is a single HTTP POST to an endpoint I provide — you send the user's message and their stored preference, you receive a plain text string back, you send it as the SMS reply. You do not design, modify, or have visibility into the prompt or response logic. HANDOFF & TRAINING — REQUIRED, NON-NEGOTIABLE I need to operate this service independently after you're done. Your proposal must include all three: - Written operator guide — user management, Stripe monitoring, log reading, redeployment - Recorded Loom walkthrough of the codebase and admin dashboard - 60-minute live handoff call DELIVERABLES - Private GitHub repo — I'm added as collaborator - Live production deployment on Railway + separate staging environment with test Twilio number - All third-party accounts set up and transferred to me (Twilio, Stripe, Railway) - README covering setup, environment variables, and deployment steps - Full training package (see above) OUT OF SCOPE - AI prompt design — I own this entirely - SMS copy — I provide all message text - Any web-based interface for end users - Mobile app WHAT I NEED IN YOUR PROPOSAL - Evidence of Twilio and Stripe experience — links to relevant work or a brief description - Timeline split into two milestones: (1) working MVP — SMS loop + onboarding, (2) full build — payments, dashboard, training - Confirmation you're comfortable with the training and handoff requirements - Fixed-price quote — budget discussed after initial message; I'm prioritizing quality and communication over lowest cost Full technical specification available to serious applicants after an initial message.