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 OpenAI Agents SDK: Which is Better in 2026?

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Agent Framework

Choosing between Letta and OpenAI Agents SDK? 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.

OpenAI Agents SDK is for: Teams that want to ship agents quickly with few abstractions: agents, tools, handoffs and guardrails, with tracing built in.

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 OpenAI Agents SDK if you want to ship a working agent with minimal boilerplate.

Letta vs OpenAI Agents SDK — Side by Side

	Letta	OpenAI Agents SDK
Category	Agent Framework	Agent Framework
What it is	Agent server and SDKs: agents with persistent memory	Code library: lightweight agent SDK
Languages	Python and TypeScript SDKs	Python, TypeScript
Licence	Apache 2.0	MIT
Managed / paid option	Letta API: free tier, Pro $20/month plus usage	None; you pay for OpenAI API usage
Project status	Active	Active
Pricing	Free · paid from $20/mo	Free
Starting price	Free tier available	Free tier available
Free tier
Rating	4.0	4.5
Best for	Agent Framework — long-term memory, stateful agents, self-host or hosted	Agent Framework — minimal abstractions, fast to ship, OpenAI 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

OpenAI Agents SDK

Very low boilerplate, fast to ship
Production-ready with tracing
Backed by OpenAI
Python & TypeScript support

Best experience tied to OpenAI models
Lighter on complex orchestration than LangGraph

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

OpenAI Agents SDK

Small set of primitives: agents, tools, handoffs and guardrails
Built-in tracing
Sandbox execution for agents that run code and use a filesystem (April 2026 update)
Other models through the LiteLLM extension (beta) or any OpenAI-compatible endpoint
Python and TypeScript
MIT 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 OpenAI Agents SDK if…

You want to ship a working agent with minimal boilerplate.
You mainly use OpenAI models and want first-party support.
Your agents run code and need a sandbox from the same SDK.

OpenAI Agents SDK review & pricing

Frequently Asked Questions

Is Letta better than OpenAI Agents SDK?⌄

What is the difference between Letta and OpenAI Agents SDK?⌄

What it is — Letta: Agent server and SDKs: agents with persistent memory. OpenAI Agents SDK: Code library: lightweight agent SDK. Languages — Letta: Python and TypeScript SDKs. OpenAI Agents SDK: Python, TypeScript. Licence — Letta: Apache 2.0. OpenAI Agents SDK: MIT. Managed / paid option — Letta: Letta API: free tier, Pro $20/month plus usage. OpenAI Agents SDK: None; you pay for OpenAI API usage.

Letta vs OpenAI Agents SDK: which is cheaper?⌄

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

Which is rated higher, Letta or OpenAI Agents SDK?⌄

In our catalog, Letta rates 4.0 out of 5 and OpenAI Agents SDK rates 4.5 out of 5, so OpenAI Agents SDK has a slight edge on reviews.

When should I skip both Letta and OpenAI Agents SDK?⌄

Skip Letta if you only need short-lived task agents. A lighter SDK is simpler. Skip OpenAI Agents SDK if you need complex orchestration with explicit state and checkpoints. LangGraph covers that.

Sources · tool facts checked October 2026