Chat-to-app builder; apps created since 2026-05-13 use TanStack Start (older ones React + Vite) with Postgres via Lovable Cloud or Supabase.
Build Kit / Community
How to build a community or social app for free
Members with profiles post, comment and react, with a feed, notifications and moderation tools. Here is a stack that costs nothing to launch, open-source code to start from, and a plan you can paste into an AI builder.
Like a forum for indie game devs, a local running club app, a Q&A site for a niche.
Your Build Kit
Community
Members with profiles post, comment and react, with a feed, notifications and moderation tools.
- User accounts
- File and photo uploads
- Chat and live updates
- Emails
- Search and filters
- Admin panel
- To launch
- $0
- After the free tiers
- ~$76/mo
- Build time with AI
- 40–100 h
Build it with
Browser builder for any JavaScript frontend with Node.js backends (Expo for mobile), plus Bolt Cloud hosting, databases and domains.
Generates Next.js apps with Tailwind and shadcn/ui and deploys them to Vercel.
Agent builds and hosts full-stack web apps with managed PostgreSQL built into every app.
The stack
Every pick has a free plan you can launch a business on, unless it says otherwise. Free tiers checked 2026-10-27.
App framework
TanStack Start MIT
Lovable builds new apps on it (React with server functions), so the code you export runs anywhere that hosts Node or Workers. React apps that need server code and deploy to Node, Workers or most serverless hosts.
Or: React + Vite, Next.js
Free and open source
Stays free
UI components
shadcn/ui MIT
The components AI tools know best: Lovable, v0 and Bolt use them by default, and the code is copied into your project. Copy-into-your-project React components built on Tailwind CSS and headless primitives, with a CLI and registry.
Free and open source
Stays free
Database
Supabase Apache-2.0
Lovable Cloud and Bolt Cloud run on Supabase, so the AI creates your tables and login for you; you can also connect your own Supabase project. A full Postgres backend (database, auth, storage, realtime, edge functions) for an MVP, especially one built with an AI app builder.
Free
- 500 MB database per project (shared CPU, 500 MB RAM)
- 5 GB egress + 5 GB cached egress per month
- 50,000 auth MAU
Free projects pause after 1 week of inactivity, and Free has no backups or point-in-time recovery.
Pro, from $25/mo per org incl. $10/mo compute credits (one Micro instance)
Login
Supabase Auth MIT
Comes with your Supabase project, and its row-level security rules use the logged-in user directly. Apps already on Supabase Postgres that want auth wired to row-level security.
Or: Clerk, Better Auth
Free
- 50,000 MAU (plus 50,000 third-party MAU)
- Social OAuth providers and anonymous sign-ins included
- Basic MFA included; phone MFA not included
It lives inside a Free Supabase project, so it pauses with the project after a week of inactivity.
Supabase Pro, $25/mo per org (100,000 MAU, then $0.00325/MAU)
Hosting
Cloudflare Workers Service
Free static files with no bandwidth cap, and commercial use is allowed. Publish on your AI builder while you build (its own custom domains need a paid plan), then connect the GitHub repo here to serve it on your domain for free. Full-stack apps and APIs on a global edge, with free static assets.
Workers Free
- Commercial use: no non-commercial clause found
- 100,000 requests/day (Error 1027 beyond that; resets 00:00 UTC)
- 10 ms CPU per request, 128 MB memory
The daily request cap is hard and each request gets only 10 ms of CPU, so heavy server rendering needs the $5 plan.
Workers Paid, $5/mo (10M requests included)
File storage
Supabase Storage Apache-2.0
Apps on Supabase that want uploads tied to Supabase Auth and Postgres policies.
Or: Cloudflare R2, UploadThing
Free
- 1 GB of file storage; 50 MB maximum file size
- 5 GB egress + 5 GB cached egress/month
- No image transformations (Pro and above only)
Free projects pause after a week without activity.
Pro, $25/mo (100 GB storage, then $0.0213/GB)
Email sending
Resend Service
Supabase’s built-in email is only for testing, so send login and app emails through your own domain. Developer-friendly transactional email for new apps.
Or: Brevo, Mailgun, Amazon SES
Free
- 3,000 emails/month, max 100/day
- 3 verified domains
- Marketing email to up to 1,000 contacts
The 100-per-day cap bites first, and received (inbound) emails count toward the quota too.
Pro $20/mo: 50,000 emails, no daily cap
Search
Postgres full-text search PostgreSQL
Already in your database and free. Move to a search service only when you need typo tolerance at scale. Searching data that already lives in Postgres.
Or: Meilisearch, Algolia, Typesense
Built into Postgres (works on any free Postgres host)
- No per-search fees
- Supabase Free: 500 MB database
- Neon Free: 1 GB storage and 100 CU-hours per project/month
It matches stemmed words, not typos; fuzzy matching needs pg_trgm and ranking needs hand-tuning.
Free; you pay only for the Postgres host
Chat and live updates
Supabase Realtime Apache-2.0
Live updates, presence and chat in Supabase apps.
Or: Ably, Pusher Channels
Free
- 200 concurrent connections
- 2M messages/month
- 100 messages/sec
The project pauses after 1 week of inactivity.
Pro $25/mo (500 connections, 5M messages)
Analytics
PostHog MIT
Startups wanting analytics, replays, flags and experiments in one tool.
Free
- 1M analytics events/month
- 5,000 web session recordings (2,500 mobile)
- 1M feature-flag requests, 1,500 survey responses
One project only; the self-hosted 'hobby’ install is officially unsupported and unlikely to scale past a few hundred thousand events.
Pay as you go: $0 base, e.g. $0.00005/event above 1M; 6 projects, 7-year retention
Error alerts
Sentry FSL-1.1-ALv2
Catching and debugging frontend and backend errors with stack traces.
Or: UptimeRobot, Better Stack
Developer
- 1 user
- 5,000 errors, 5M tracing spans, 50 session replays per month
- 5 GB logs, 1 cron monitor, 1 uptime monitor
Only one user, so adding a teammate means the paid Team plan.
Team $26/mo billed yearly ($29 monthly): unlimited users, 50k errors
Start from open source
Worth studying before you prompt, or self-host one instead of building from scratch.
Q&A community platform (Stack Overflow-style) with plugins.
Lightweight, extensible forum software; version 2.0 is now stable.
Full-featured community forum with moderation, trust levels, plugins and email integration.
GPL: share source if you distribute modified versions (hosting alone does not trigger it).
Customer feedback board where users post and vote on ideas.
AGPL: you must publish your changes if you run it as a service.
UI kit and libraries
Copy-into-your-project React components built on Tailwind CSS and headless primitives, with a CLI and registry.
Utility-first CSS framework.
The official component/template collection, Tailwind Plus, is paid.
Open-source icon set with packages for React and other frameworks.
Self-host open-source fonts as npm packages.
Font files keep their original licenses (mostly SIL OFL).
Performant form state and validation for React.
TypeScript-first schema declaration and validation.
Headless table and data-grid logic for React and other frameworks.
v9 is the current major version.
Headless rich-text editor framework built on ProseMirror.
Collaboration, comments, AI toolkit and other Platform features are paid (Start $49/mo, Team $149/mo, Business $999/mo; 30-day trial).
AI skills and MCP servers
Guides and connections that make your AI builder produce better code.
Plan the product and key user action first, build UI one component at a time, use real copy and style keywords, ask questions in Plan mode.
- Bolt: Prompt effectivelyService
Plan the app and first prompt, use Enhance prompt, and make small one-at-a-time changes.
Describe the product surface, context of use, and constraints and taste (2025-12-15); the Academy guide adds patterns and starter prompts.
- AGENTS.mdMIT
Open 'README for agents’ format stewarded by the Agentic AI Foundation (Linux Foundation); used by 60k+ open-source projects.
Add an AGENTS.md file at the repository root
The plan
- 1
Write down the plan
30 minutes- Name the people who use it and the one job it does for them.
- List the screens: Sign up and profiles; Posting with text and images; Comments, reactions and notifications.
- Sketch them on paper or in Excalidraw. Rough is fine.
- Download this kit as AGENTS.md and keep it in your project: it’s the brief your AI tool reads first.
- 2
Set up the foundation
Day 1- Start a new Lovable project and paste the prompt below.
- Connect Supabase from Lovable’s integrations, then turn on email and Google login.
- Publish it and open it on your phone to check it works.
- Connect the project to GitHub so you own the code.
Prompt for Lovable
Build a community or social app: a community or social app (a forum for indie game devs) The main screens: Sign up and profiles; Posting with text and images; Comments, reactions and notifications. Use Supabase for the database and login (email and Google). Turn on row-level security on every table so people only see their own data. Use shadcn/ui components, a clean light design, and make every screen work on a phone. Don’t add payments yet. Start with sample data so I can click through it.
- 3
Build the core
Days 2–7- Sign up and profiles
- Posting with text and images
- Comments, reactions and notifications
- A feed or topic list with search
- Moderation: report, hide and ban
Prompt for Lovable
Now build these, one at a time, and let me test each before the next: 1. Sign up and profiles 2. Posting with text and images 3. Comments, reactions and notifications 4. A feed or topic list with search 5. Moderation: report, hide and ban Store uploads in Supabase Storage, check file type and size on upload, and keep files private unless they’re meant to be public. Add search with Postgres full-text search. Use Supabase Realtime for live updates.
- 4
Send emails
Week 2- Send emails through Resend, and add its DNS records (SPF and DKIM) so they don’t land in spam.
Prompt for Lovable
Send account emails with Resend from a server function.
- 5
Get it ready to launch
Week 2–3- Add PostHog and track the one action that means it’s working (a booking, a sale, a sign-up).
- Add Sentry so errors reach you before users complain.
- Go through the launch checklist below.
- Add a privacy policy and terms, then connect your own domain.
- Show it to ten people who have the problem, and watch them use it.
Prompt for Lovable
Review the whole app for security and launch problems before I go live: - every table has row-level security (or server-side checks) and I can’t read another user’s data, - no secret keys in the browser bundle or the repo, - inputs are validated on the server, and sign-up, login and forms are rate-limited, - error pages and empty states exist for every screen, - it works on a phone and with the keyboard. List what you find, fix the serious ones, and tell me what’s left.
Before you launch
- Row-level security (or server checks) on every Supabase table, tested with two accounts.
- No secret keys in browser code or in git. Rotate any that leaked.
- Server-side validation for every form, plus rate limits on sign-up and login.
- Uploads checked for type and size; private files served with signed links.
- Your sending domain verified (SPF, DKIM), so emails reach the inbox.
- Backups: know how to restore your data (free database plans often have none).
- Privacy policy, terms, and a way for people to contact you.
- Error alerts on, and an uptime check on the home page.
- Tested on a phone, with a keyboard only, and with a slow connection.
Risks to plan for
- The empty-room problem: seed content and invite the first 50 members yourself.
- Abuse arrives early: reporting and blocking are not optional.
- Hosting user content brings legal duties (takedowns, privacy requests).
Free tiers and prices were checked by hand on 2026-10-27. They change often, so each pick links to its own site. Compare every option
What a community or social app usually needs
- User accounts
- Chat and live updates
- File and photo uploads
- Emails
- Admin panel
- Search and filters