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.

Letta vs smolagents: Which is Better in 2026?

Name: App Stack Builder
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Agent Framework

Choosing between Letta and smolagents? Both are popular agent framework tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.

Letta is for: Teams building agents that must remember users and context across sessions and restarts, with memory as the core design.

smolagents is for: Developers who want a small, readable agent library where agents act by writing and running Python code.

Quick verdict

There’s no single winner; pick on your constraint. Choose Letta if your agent must remember users and past sessions over weeks or months. Choose smolagents if you want a minimal library you can fully understand and modify.

Letta vs smolagents — Side by Side

	Letta	smolagents
Category	Agent Framework	Agent Framework
What it is	Agent server and SDKs: agents with persistent memory	Code library: minimal code-writing agents
Languages	Python and TypeScript SDKs	Python
Licence	Apache 2.0	Apache 2.0
Managed / paid option	Letta API: free tier, Pro $20/month plus usage	None
Project status	Active	Active
Pricing	Free · paid from $20/mo	Free
Starting price	Free tier available	Free tier available
Free tier
Rating	4.0	4.1
Best for	Agent Framework — long-term memory, stateful agents, self-host or hosted	Agent Framework — code-writing agents, minimal library, Hugging Face models

Pros & Cons

Letta

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

Younger project with a moving API
Memory model is opinionated

smolagents

Small enough to read end to end in an afternoon
Code-as-action beats JSON tool calls for many tasks
Hugging Face Hub integration

Deliberately minimal — no orchestration layer
Running model-written code needs a sandbox

Key Features Compared

Letta

Persistent, self-editing agent memory (from the MemGPT research)
Agents keep their state across restarts
Self-hosted server, or the hosted Letta API
Hosted plans: free tier and Pro at $20 a month with pay-as-you-go usage
Letta Code, an open-source coding agent with memory across sessions
Apache 2.0 licence

smolagents

CodeAgent writes Python as its actions instead of JSON tool calls
Sandboxed execution through E2B or Docker
Hugging Face Hub integration for models and tools
Small codebase you can read end to end
Apache 2.0 licence

Choose Letta if…

Your agent must remember users and past sessions over weeks or months.
You want agents that keep state when the process restarts.
You want the choice of self-hosting or a hosted API.

Letta review & pricing

Choose smolagents if…

You want a minimal library you can fully understand and modify.
Your tasks suit agents that write code, such as data analysis.
You use open models from the Hugging Face Hub.

smolagents review & pricing

Frequently Asked Questions

Is Letta better than smolagents?⌄

What is the difference between Letta and smolagents?⌄

What it is — Letta: Agent server and SDKs: agents with persistent memory. smolagents: Code library: minimal code-writing agents. Languages — Letta: Python and TypeScript SDKs. smolagents: Python. Managed / paid option — Letta: Letta API: free tier, Pro $20/month plus usage. smolagents: None.

Letta vs smolagents: which is cheaper?⌄

Letta pricing: Free · paid from $20/mo. smolagents pricing: Free. Confirm current pricing on each tool's official site, as plans change.

Which is rated higher, Letta or smolagents?⌄

In our catalog, Letta rates 4.0 out of 5 and smolagents rates 4.1 out of 5, so smolagents has a slight edge on reviews.

When should I skip both Letta and smolagents?⌄

Skip Letta if you only need short-lived task agents. A lighter SDK is simpler. Skip smolagents if you need orchestration, memory or deployment built in. smolagents leaves those to you.

Sources · tool facts checked October 2026