AI assistants and search decision
Google Gemini
A chat UI is easy, but Gemini's model access, Google ecosystem integration, multimodality, storage tie-ins, and platform distribution are not solo-buildable.
Visit website↗Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need — the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship.
What a replacement has to do
- Build a multi-model chat app with document upload and optional Google API integrations.
What it still won’t have
- frontier models
- Google app integrations
- mobile/native distribution
- multimodal stack
- reliability
What remains hard
- Proprietary models
- Integration maintenance
- Infrastructure at scale
First-year cost
The build hours below are a category default, not an estimate for this product. Change them to your own numbers and the comparison follows.
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 1 seat.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build me a personal chat client on the Gemini API to replace my Google AI Pro subscription with per-token billing. Requirements: - A local web app: Node + Express + better-sqlite3, one page, binds to localhost. - Gemini API key in .env, with optional Claude and OpenAI keys too; a model picker per conversation. - Streaming responses with Markdown and code-block rendering; history in SQLite with FTS5 search across old conversations. - Upload PDFs and images and pass them through to models that accept them. - System-prompt presets as .md files in ./prompts/, selectable per chat. - Export any conversation to a Markdown file. - No accounts, no telemetry; history stays on my machine, only prompts go to the APIs. - Out of scope: Gmail, Docs, and Drive integrations, and mobile apps. Do not build Google Workspace OAuth; that ecosystem tie-in is the subscription. - README: where to create each API key, a rough cost table per model, and state that per-token billing can land above or below $20/month depending on use, the model itself is only rentable.
