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.

Agent FrameworkFree tier

Letta: Pricing, Features & Alternatives

Agents with persistent memory — the MemGPT research, productised.

Letta Pricing Plans (2026)

Plan	Price	Highlights
Open sourcePopular	Free (self-hosted)	Persistent agent memory · Memory blocks and archival storage · Agent Development Environment
Cloud	$20 / month	Hosted agents · Managed memory storage · Usage dashboards

Pricing summary: Free · paid from $20/mo. Always confirm current pricing on the official site.

Key Letta Features

Persistent agent memory
Memory blocks and archival storage
Agent Development Environment
REST API

Pros

+Memory is the design centre, not an add-on
+Agents survive restarts with state intact
+Comes from the MemGPT paper

Cons

−Younger project with a moving API
−Memory model is opinionated

Best Letta Alternatives

Compare all

Mastra

Free

Pydantic AI

Free

Vercel AI SDK

Free

LangChain

Free · paid from $39/mo

LangGraph

Free

LlamaIndex

Free

Letta FAQ

What is Letta used for?⌄

Letta is a agent framework tool. Agents with persistent memory — the MemGPT research, productised.

Is Letta free?⌄

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

How much does Letta cost?⌄

Letta offers a free tier, with paid plans starting at $20/month.

What are the best Letta alternatives?⌄

Popular Letta alternatives include Mastra, Pydantic AI, Vercel AI SDK, LangChain, LangGraph. Compare pricing and features on our Letta alternatives page.

Not sure if Letta fits your stack?

Get a free, AI-powered tech stack tailored to your budget, app type, and team size — including the best agent framework pick for you.

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