What is App Stack Builder?

App Stack Builder is a free AI-powered tool that helps founders and developers choose the right tech stack for their projects based on budget, app type, team size, and skill level.

What is the best tech stack for SaaS in 2026?

The best tech stack for SaaS in 2026 typically includes Next.js 16 for frontend, Supabase for database and auth, Vercel for hosting, Stripe for payments, and PostHog for analytics. App Stack Builder can generate a personalized recommendation based on your specific budget and requirements.

Is App Stack Builder free to use?

Yes, App Stack Builder is completely free to use. You can generate unlimited tech stack recommendations without any cost.

What types of apps can I build with the recommended stacks?

App Stack Builder supports various app types including SaaS applications, web apps, mobile apps, e-commerce stores, internal tools, and AI/ML products.

How much does a SaaS tech stack cost per month?

A modern SaaS tech stack can cost anywhere from $0-50/month for bootstrapped startups using free tiers, $100-300/month for growth-stage startups, to $500+/month for enterprise-ready infrastructure. App Stack Builder helps you find the best tools within your specific budget.

What is the best tech stack for solo founders?

For solo founders, we recommend Next.js + Vercel (free), Supabase (free tier), Supabase Auth (free), Stripe (pay as you go), and Plausible or PostHog for analytics. This stack can run your entire SaaS for under $50/month.

Can I export my tech stack recommendations?

Yes, you can export your tech stack recommendations as a PDF document or copy them to your clipboard. You can also share a link to your stack with others.

Usage-Based Billing & MeteringFree tier

Flexprice: Pricing, Features & Alternatives

Flexprice is a developer-first, AGPL-licensed billing platform (6K+ GitHub stars) aimed at AI and API companies. It meters events, manages wallets and prepaid credits, supports usage, credit, seat and hybrid pricing, and generates invoices. Unusually for this category it publishes prices: Free covers 100K events a month (up to $100K cumulative billing), Build is $500/month for 1M events and Scale $1,000/month for 5M, with 20% off yearly. The open-source edition is free to self-host, and Mission Critical adds VPC or on-premise deployment.

Flexprice Pricing Plans (2026)

Plan	Price	Highlights
Open Source	$0 (self-hosted, AGPL)	Metering, credits and invoicing · Community support
Free	$0	100K events / month · Up to $100K cumulative billing
BuildPopular	$500 / month	1M events / month
Scale	$1,000 / month	5M events / month
Mission Critical	Custom	VPC or on-premise · Custom volume

Pricing summary: Free · paid from $500/mo. Always confirm current pricing on the official site.

Key Flexprice Features

1M events / month

Pros

+Open source with a free hosted tier
+Published prices, which is rare in billing
+Built for credit and wallet models common in AI products

Cons

−Younger than Lago, Orb and Metronome
−Paid cloud jumps straight to $500/month
−Smaller ecosystem of finance integrations

Best Flexprice Alternatives

Compare all

Lago

Free · paid from $599/mo

Metronome

Usage-based

Orb

Usage-based

Flexprice Compared

Flexprice vs Lago Flexprice vs Metronome Flexprice vs Orb

Flexprice FAQ

What is Flexprice used for?⌄

Flexprice is a usage-based billing & metering tool. Open-source billing for AI and API products: usage, credits and hybrid pricing with published prices and a free cloud tier.

Is Flexprice free?⌄

Yes — Flexprice has a free tier you can start with, and paid plans for more usage and features.

How much does Flexprice cost?⌄

Flexprice offers a free tier, with paid plans starting at $500/month. Some plans are usage-based (pay-as-you-go).

What are the best Flexprice alternatives?⌄

Popular Flexprice alternatives include Lago, Metronome, Orb. Compare pricing and features on our Flexprice alternatives page.