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.

MCP Testing & HostingFree tier

MCP Playground Online: Pricing, Features & Alternatives

Name: App Stack Builder
Availability: InStock

MCP Playground Online covers the whole MCP testing loop in the browser. The server tester connects to any remote server over HTTP, SSE or Streamable HTTP, lists its tools, prompts and resources, calls them with real arguments and shows every JSON-RPC message.

MCP Evals writes a test suite from your own tools and runs it against an AI agent: code decides pass or fail, and a scoring model grades the answers. The security scanner runs 35+ checks across transport, auth, protocol compliance, injection and disclosure, mapped to the OWASP MCP Top 10. AI Readiness generates around 120 questions your users would ask, rates how well each tool description answers them, and writes rewrites for the weak ones.

MCP Agent Studio runs an agent over up to four servers at once, remote or a local stdio process, and compares 60+ models side by side on speed, cost and accuracy. It can also deploy a hosted MCP server with a live HTTPS URL in under a minute and export an agent as an API.

The testing tools are free with no sign-up. Agent Studio runs on credits, with free credits on sign-up. As of October 2026.

MCP Playground Online Pricing Plans (2026)

Plan	Price	Highlights
FreePopular	$0	Server and client tester · MCP evals and AI Readiness review · OWASP MCP Top 10 security scan (35+ checks)

Pricing summary: Free. Always confirm current pricing on the official site.

Key MCP Playground Online Features

Server and client tester
MCP evals and AI Readiness review
OWASP MCP Top 10 security scan (35+ checks)
Agent Studio with 60+ models (free credits on sign-up)
Hosted MCP servers and mock servers

Pros

+Evals, security scan and AI readiness in one free tool
+Compare 60+ models on your server in Agent Studio
+Nothing to install, and hosted MCP servers in under a minute

Cons

−Server tester reaches remote servers only (Agent Studio handles stdio)
−Agent Studio usage beyond free credits is not priced publicly

Best MCP Playground Online Alternatives

Compare all

MCP Inspector

Free

Smithery

Free · paid from $10/mo

MCP Playground Online Compared

MCP Playground Online vs MCP Inspector MCP Playground Online vs Smithery

MCP Playground Online FAQ

What is MCP Playground Online used for?⌄

MCP Playground Online is a mcp testing & hosting tool. Browser-based MCP platform: test servers, run evals, scan against the OWASP MCP Top 10, check AI readiness and try them with 60+ models in Agent Studio.

Is MCP Playground Online free?⌄

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

How much does MCP Playground Online cost?⌄

MCP Playground Online is free to use.

What are the best MCP Playground Online alternatives?⌄

Popular MCP Playground Online alternatives include MCP Inspector, Smithery. Compare pricing and features on our MCP Playground Online alternatives page.