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.

AI Evals & Agent Testing

Coval: Pricing, Features & Alternatives

Coval tests voice and chat agents the way self-driving teams test cars: it runs your agent against many simulated callers, personas and scenarios before launch, scores every conversation, then monitors live calls in production with alerts and human review queues. It has a REST API, CLI and MCP server, and states SOC 2 Type II, HIPAA and GDPR compliance. Starter is $100/month (100 simulation minutes, 1,000 monitored calls, $0.40 per extra simulation minute), Growth $500/month (1,000 simulation minutes, 10,000 monitored calls) and Enterprise from $4,500/month. Plans include unlimited seats and a 7-day trial that requires a card.

Coval Pricing Plans (2026)

Plan	Price	Highlights
Starter	$100 / month	100 simulation minutes · 1,000 monitored calls · $0.40 per extra simulation minute
GrowthPopular	$500 / month	1,000 simulation minutes · 10,000 monitored calls · $0.25 per extra simulation minute
Enterprise	From $4,500 / month	Custom limits · Custom voice models · Unlimited projects

Pricing summary: From $100/mo. Always confirm current pricing on the official site.

Key Coval Features

1,000 simulation minutes
10,000 monitored calls
$0.25 per extra simulation minute
25 concurrent simulations

Pros

+Built for voice agents, with realistic simulated callers
+Testing and production monitoring in one
+Published prices and unlimited seats

Cons

−No free tier; the trial needs a card
−Simulation minutes run out quickly at scale
−Mostly voice-focused

Best Coval Alternatives

Compare all

DeepEval

Free · paid from $200/mo

Promptfoo

Free · paid plans by quote

Ragas

Free

Coval Compared

Coval vs DeepEval Coval vs Promptfoo Coval vs Ragas

Coval FAQ

What is Coval used for?⌄

Coval is a ai evals & agent testing tool. Simulation and monitoring for voice AI agents: test against simulated callers and personas before launch, then score live calls.

Is Coval free?⌄

Coval does not offer a permanent free tier; paid plans start at $100/month.

How much does Coval cost?⌄

Coval plans start at $100/month.

What are the best Coval alternatives?⌄

Popular Coval alternatives include DeepEval, Promptfoo, Ragas. Compare pricing and features on our Coval alternatives page.