What are you building today?
Describe it in plain words. Bookbag writes a real app, shows you every file it touched, and puts it online when you are happy with it.
- app/page.jsx
- components/ServiceList.jsx
- components/BookingForm.jsx
- app/globals.css
A proper cut,
booked in thirty seconds.
Walk-ins welcome. Tuesday to Saturday, 9 till 6.
Cut
£24
Cut & beard
£32
Hot towel
£18
Why we built it
You have probably been burned by one of these
These are the complaints people make about AI app builders, over and over. We read a lot of them. Each one below is something Bookbag does differently — not a promise, a feature you can go and use.
Credit anxiety
“It burned my credits fixing its own mistakes.”
Bring your own provider key and builds cost zero credits — you pay your provider, at their price. On platform credits, every run itemises the model, the tokens in and out and what it charged, so nothing moves without a line against it.
Regressions
“It fixed one thing and broke three others.”
Every build is a version with a snapshot of the files. When a change makes things worse, restore the previous one and carry on — a bad run is an undo, not a rewrite.
Security holes
“My API keys shipped in the bundle and /admin had no login.”
A security pass reads the project for exactly these: secrets hardcoded into client code, an .env served to the public, admin routes with no check on them, permissions trusted from the browser. It tells you where, and offers to fix it.
The wall
“Around month three it got too big and the AI fell over.”
The whole project is readable — a file tree and the source of every file, in ordinary Next.js, React and Tailwind. When it outgrows the chat, hand it to a developer instead of starting again.
Lock-in
“I could not get my code out.”
Download the entire project as source whenever you like. It runs anywhere Node runs. Nothing about it is ours to hold.
Generic design
“Everything it makes looks like the same purple gradient.”
Pick from a curated set of designs before the first build — each one steers layout, type and colour throughout, so the result looks like a decision rather than a default.
The one that fixes most of the others is your own API key. It is free, it takes a minute, and it takes the meter out of the loop.
Your models
Use your own model and stop counting credits
Most builders meter you on tokens you cannot see, and a long debugging session quietly costs more than the feature was worth. Bookbag lets you put your own provider key in and take the meter out of the loop entirely.
- Paste a key from OpenAI, Anthropic, Google or any OpenAI-compatible endpoint.
- The key is checked against the provider before it is saved, then encrypted at rest.
- Builds on your own key cost zero credits. You pay your provider, at their price.
- Choose a different model per project — a cheap one for drafts, your best one for the hard parts.
Anthropic
••••••••4f1c
OpenAI
••••••••9be2
Not connected
This build used 1,684 tokens on your own key — 0 credits charged.
How it works
Three steps, no setup
No install, no config files, no choosing a framework. You start typing and you end up with something running.
- 01
Describe it
Write what you want the way you would explain it to a person. Pick a design to start from if you have a look in mind, or let Bookbag choose one.
- 02
Watch it build
The preview updates as the app takes shape, and every file the agent creates or edits is listed as it happens. Nothing is hidden behind a spinner.
- 03
Publish it
One click puts it on a real URL. Keep iterating afterwards — each build is a version you can compare and roll back to.
Who it’s for
If you can describe it, you can build it
Founders
Put the idea in front of real people this week. Change it on Thursday because of what they said on Wednesday.
Product and ops teams
The internal tool nobody has time to build — the tracker, the request form, the small dashboard — without waiting for a sprint.
Designers
A prototype that actually runs, with real data and real states, instead of a flow of screens that only works if you click in the right order.
Engineers
Skip the scaffolding. Read the diff, keep what is right, and use your own model so the cost is a line on a bill you already have.
Pricing
Free to start, and free to leave
The code is yours, the URL is yours, and if you would rather pay your model provider than pay us for tokens, that is a supported way to use Bookbag.
Free
Start here. No card.
- Credits to spend the moment you sign up
- A fresh allowance every month
- Publish to a real URL
- Version history and rollback
- Download your source any time
Your own key
The meter comes out.
- Everything in Free
- Builds on your key cost zero credits
- You pay your provider directly, at their rate
- Pick the model per project
- Keys verified, then encrypted at rest
Team
For a group that ships together.
- Shared platform models your team builds on
- Per-person allowances an admin controls
- A ledger of who spent what, per run
- Skills and designs curated for your brand
The idea you keep not getting to
Build it tonight. It costs nothing to find out whether it works.