# SaaS development, from first version to paying customers > SaaS development by App369, a one-developer studio in Miami: a scoped first version in about 4 weeks, Stripe subscriptions, integrations and MCP. Fixed prices. Canonical: https://app369.com/service/saas-development/ A first SaaS version takes about 4 weeks from a signed quote, after a written scoping in 3 business days. Simon Dziak builds the screens, the Stripe billing and the backend as one developer, so they are designed together. Scoping is $450 and ends in a fixed price for the build, from $6,000. Already live and need billing? Stripe Billing Fix and Setup is $950. Fixed prices [**All fixed-price offers**](https://app369.com/fixed-price/) - [from $6,000**Web App MVP Sprint**A scoped web app MVP in Vue/Nuxt or React, with a fixed quote after a $450 written scoping.**See scope and start**](https://app369.com/fixed-price/web-app-mvp/) - [$950**Stripe Billing Fix and Setup**Subscriptions, webhooks, customer portal and failed payments set up or fixed, tested in Stripe test mode.**See scope and start**](https://app369.com/fixed-price/stripe-billing-setup/) - [from $1,495/month**Monthly Dev Subscription**One development request at a time, most back in about 2 business days. Pause or cancel anytime.**See scope and start**](https://app369.com/fixed-price/monthly-dev-subscription/) Something else? [**Describe your project**](https://app369.com/contact/) What a SaaS needs ## **The parts of a SaaS product App369 builds** - 01 ### **A first version, scoped in writing** The scoping names the users and roles, the screens, the data model and the integrations, says what waits for a later version, and ends in a fixed price and timeline. The build ships with the code in your repository, deployed to your own Netlify, Vercel or Google Cloud account. [**Web App MVP Sprint**](https://app369.com/fixed-price/web-app-mvp/) [**MVP development**](https://app369.com/service/mvp-development/) - 02 ### **Subscriptions and billing in Stripe** Plans, upgrades, the customer portal and failed payments, tested before real money moves. Stripe’s docs say to use test clocks “to advance simulated time in a sandbox and see how your subscriptions and invoices change”, so a renewal or a failed annual payment is tested without waiting a year. [**Stripe Billing Fix and Setup**](https://app369.com/fixed-price/stripe-billing-setup/) [**Hire a Stripe developer**](https://app369.com/service/hire-stripe-developer/) - 03 ### **Accounts and separate customer data** Sign-in and roles in the agreed scope, with access checked on the server and tested, so each customer’s records stay separate from everyone else’s. [**Backend and API development**](https://app369.com/service/backend-development/) [**Firebase Security Rules Audit**](https://app369.com/fixed-price/firebase-security-rules-audit/) [**Supabase RLS fixes**](https://app369.com/service/supabase-rls-fix/) - 04 ### **Integrations your customers ask for** A connection between your product and another system, built against both sets of API docs and test credentials and delivered with tests. [**API Integration**](https://app369.com/fixed-price/api-integration/) - 05 ### **A connector for AI assistants** The Model Context Protocol’s own docs call MCP “an open-source standard for connecting AI applications to external systems”. A connector puts up to 8 tools over your existing REST API, for Claude with API-key sign-in, and for ChatGPT with the OAuth sign-in add-on. [**MCP Connector for your SaaS**](https://app369.com/fixed-price/mcp-server-for-saas/) - 06 ### **Work after launch** A monthly plan instead of a quote per job: send requests, one is worked on at a time, and most come back in about 2 business days. Pause or cancel anytime. [**Monthly Dev Subscription**](https://app369.com/fixed-price/monthly-dev-subscription/) [**Web app development**](https://app369.com/service/web-apps/) App369’s own SaaS ## **Workspace369, built and run by App369** Workspace369 is a client-work platform for freelancers and small agencies. App369 built it and runs it, so these parts are in production today. It is App369’s own product, not client work. - **✓**### **Plans billed through Stripe** Workspace369 plans are Stripe subscriptions, and Stripe Connect pays freelancers directly on their own invoices and proposals. - **✓**### **Team workspaces** Every workspace keeps its own members and data, with access rules covered by automated emulator tests. - **✓**### **A server for each job** More than 20 TypeScript Cloud Functions codebases for billing, messaging, AI, search, PDFs and scheduling, each deployed on its own. - **✓**### **An MCP server** Claude and ChatGPT can reach a user’s workspace data through OAuth, scoped to that user. - Vue - Nuxt - React - TypeScript - Firebase - Google Cloud - Stripe - MCP FAQ ## **Questions before you start**
**How much does SaaS development cost with App369? ** The written scoping is $450, and the build of the first version is from $6,000, at a fixed price set in the quote before work starts. Stripe Billing Fix and Setup is $950, and monthly work after launch is from $1,495 a month. Hosting and third-party services are billed to your own accounts.
**How long does the first version take? ** About 4 weeks from the signed quote. The scoping takes 3 business days, and the exact build timeline is in the quote.
**Who owns the code? ** You do. The code goes in your repository and the app is deployed to your own Netlify, Vercel or Google Cloud account, with handover notes and 14 days of written fixes for defects in the agreed scope.
**Can you add billing to a SaaS that is already live? ** Yes. Stripe Billing Fix and Setup covers products and prices for up to 3 plans, monthly or yearly, with every flow run in test mode with test clocks and delivered as a pull request. It takes 5 business days after repo access and a test-mode restricted key arrive.
**Is a native mobile app included? ** No. The Web App MVP Sprint is a web app. A native mobile app is quoted separately.
**Do I need a call first? ** No. Scoping and the build happen in writing by email. If you want to talk it through, consultations are paid: $100 per 15 minutes, paid upfront.
**Who does the work? ** Simon Dziak, who founded App369, does every part of the work. App369 is a one-developer studio in Miami.
### **Sources** - [Stripe docs: Test your Billing integration (test clocks)](https://docs.stripe.com/billing/testing/test-clocks) - [Model Context Protocol: What is MCP?](https://modelcontextprotocol.io/docs/getting-started/intro) Not a fixed-price job? ## **Describe it and get a written quote** Send what you need built or fixed. You get a written scope, a fixed price and a timeline; Simon replies by email, usually within one business day. [**Describe your project **→](https://app369.com/contact/) [**Instant quote**](https://app369.com/instant-quote/) Prefer a call? Consultations are $100 per 15 minutes, paid upfront.