- Builds
- AI chatbot app over your own content
AI chatbot app over your own content
A deployed chat assistant that answers from your own docs, FAQ and product pages. It stores each user's history, runs moderation on input and has a spend cap on the AI API.
- Prices checked
- 16 Oct 2026
- Updated
- 17 Oct 2026
- Exchange rate
- 1 USD = £0.7489
- Sources
- 7
The stack
HOSTVercelNext.js native, Secret env vars£14.98
- Layer
- Hosting
- Plan
- Pro $20/seat/mo
- What it does here
- Next.js native, Secret env vars
- Note
- Hobby is non-commercial only, so it isn't used here
HOSTNetlifyCheaper hosting optionFree / £6.74
- Layer
- Hosting (alt)
- Plan
- Free $0 (300 credits) or Personal $9
- What it does here
- Cheaper hosting option
- Note
- Whether Netlify Free allows commercial use is not confirmed
DATAAUTHSupabasePostgres, auth and RLS in oneFree / £18.72
- Layer
- DB + auth + history
- Plan
- Free (50,000 MAU, 500 MB DB) or Pro from $25
- What it does here
- Postgres, auth and RLS in one
- Note
- Free pauses after 1 week of inactivity
AIOpenAIgpt-5-mini for answers, free moderationusage
- Layer
- AI API
- Plan
- Usage only: gpt-5-mini $0.25 in / $2.00 out per 1M tokens; gpt-5-nano $0.05 / $0.40; omni-moderation free
- What it does here
- gpt-5-mini for answers, free moderation
- Note
- No free tier found. VAT treatment not recorded
——Finds relevant content chunksNot yet priced
- Layer
- Retrieval / embeddings
- Plan
- —
- What it does here
- Finds relevant content chunks
- Note
- Excluded from totals until priced
OPSGitHubDependabot + secret scanningFree
- Layer
- Monitoring and security
- Plan
- Free
- What it does here
- Dependabot + secret scanning
- Note
- Secret scanning + push protection free on public repos; private Secret Protection price not found
Steps
Scaffold a Next.js chat UI and deploy it on Vercel Pro (or Netlify).
Done when the empty chat page loads at your live URL.
Create Supabase tables for users, conversations and messages, with RLS so each user sees only their own rows (docs).
Done when a second test user can't read the first user's messages.
Ingest your content and retrieve the relevant chunks for each question. This retrieval approach is not priced.
Done when a question about your docs returns the right passage.
Call gpt-5-mini from the server only, and keep the API key as a Secret env var (docs).
Done when the bot answers, and the key doesn't appear in the browser bundle or network tab.
Run user input through omni-moderation (free) before the model call.
Done when a flagged test input is blocked before it reaches the model.
Set an OpenAI project budget or limit, and log tokens per conversation.
Done when the budget is set and token counts show up per conversation.
Watch out for
- Vercel Hobby is non-commercial, so plan on Pro from your first paid or business user.
- Token cost grows with history length, so trim or summarise history.
- Supabase Free pauses after a week of inactivity, so a live bot needs Pro.
- Never expose the OpenAI key in client-side code.
What it costs each month
| Stage | Platform (no Lovable) | Stripe fees | Total | + Lovable Pro |
|---|---|---|---|---|
| (a) Free (Netlify Free + Supabase Free) | £0.00 | £0.00 | £0.00 | £22.00 |
| (b) Paid, lean (Netlify Personal £6.74 + Supabase Pro £18.72) | £25.46 | £0.00 | £25.46 | £47.46 |
| (c) Paid, recommended (Vercel Pro £14.98 + Supabase Pro £18.72) | £33.70 | £0.00 | £33.70 | £55.70 |
| (c) + assumed tokens (adds £4.87 of OpenAI usage, assumption) | £38.57 | £0.00 | £38.57 | £60.57 |
- Token usage is an assumption, not a measurement. The assumed volume is 10M input + 2M output tokens a month on gpt-5-mini: $2.50 + $4.00 = $6.50, which is £4.87.
- Excluded: VAT (USD vendors quote ex-VAT), usage overages, domains, retrieval/embeddings (not yet priced), and Stripe fees if you charge for the bot.
- Neither total uses Vercel Hobby, because a monetised or business chatbot counts as commercial use.
Still open
- The token volume (10M in / 2M out) is an assumption. Real usage is unknown until a hands-on test.
- Retrieval/embeddings cost and any vector add-on are not yet priced.
- Whether Netlify Free allows commercial use is not confirmed on Netlify's pricing page.
- OpenAI VAT treatment is not recorded. Nothing has been tested hands-on.
Sources
- Stackguide desk research, checked 16 Oct 2026
- OpenAI pricing, checked 2026-10-16
- Vercel, Netlify and Supabase prices: Vercel pricing, Netlify pricing, Supabase pricing, checked 2026-10-16
- Supabase RLS and Vercel Secret env vars, checked 2026-10-16
- FX: Bank of England reference rate (series XUDLUSS): 1 USD = 0.7489 GBP on 16 Oct 2026, checked 2026-10-23
Change log
| Date | Change | Source |
|---|---|---|
| 2026-10-16 | New desk-costed build | Stackguide desk research |
| 2026-10-17 | FX label clarified as 15 Oct 2026 close | Editorial update |
| 2026-10-23 | USD prices re-converted at the Bank of England reference rate, 1 USD = 0.7489 GBP (16 Oct 2026), the one rate used site-wide (was 0.7535, exchangerates.org.uk 15 Oct 2026 close); £ figures and totals re-derived | Bank of England series XUDLUSS, checked 2026-10-23 |