# Vite ChatGPT Agent

An AI chat and research assistant built with Vite, TanStack Start, Hono, the AI
SDK and OpenRouter: streaming responses, model selection, optional Firecrawl web
research, file attachments, and conversations saved in IndexedDB. Ported from
`nextjs-templates/nextjs-chatgpt`.

Runs in the nodesandbox runtime: `npm install` → `npm run dev` → port 3000.

## Getting started

```sh
cp .env.example .env.local   # set OPENROUTER_API_KEY
corepack enable              # uses the Yarn 4 pinned in package.json
yarn install
yarn dev                     # http://localhost:3000
```

| Script           | What it does                                              |
| ---------------- | --------------------------------------------------------- |
| `yarn dev`       | Vite dev server with SSR                                  |
| `yarn build`     | Production build; Nitro packages the server for the host  |
| `yarn start`     | Run the Node build from `.output/`                        |
| `yarn typecheck` | `tsc`                                                     |
| `yarn test`      | Streaming tests against the real API handler (no network) |

## Environment

`OPENROUTER_API_KEY`, `OPENROUTER_MODEL` and `FIRECRAWL_API_KEY` are
server-only (no `VITE_` prefix), so they never reach client JavaScript.
`vite.config.mjs` loads `.env` / `.env.local` into `process.env` in dev; on
Vercel set them in the project settings.

## Deploying to Vercel

Push and deploy — no dashboard settings. `vercel.json` selects the TanStack
Start preset and installs with Yarn 4 via Corepack; Nitro writes
`.vercel/output/` during `vite build` with a 300s function duration for long
agent runs.

## nodesandbox compatibility

The sandbox runs Vite's native tools as WebAssembly (`NAPI_RS_FORCE_WASI`), and
its installer resolves from `package.json` ranges rather than `yarn.lock`. The
toolchain versions match `vite-shopify-storefront`:

- `vite` is pinned to **8.3.2** (rolldown 1.2.x WASI binding).
- WASI bindings (`@rolldown/binding-wasm32-wasi`, `@tailwindcss/oxide-wasm32-wasi`)
  are **not** listed: the runtime installs each package's `*-wasm32-wasi`
  optional dependency itself, and npm on other hosts rejects them.
- `@vitejs/plugin-react` (6.0.0) and Tailwind (4.3.1) match the harness samples.
- Nitro (the hosting adapter) only loads for `vite build`, never in `vite dev`.

## Layout

```
src/
  server.ts        Start's server entry: Hono routes /api/*, the rest goes to Start
  server/
    app.ts         Hono API
    chat.ts        POST /api/chat — streams the agent's reply
    chat.functions.ts  server function for the page's server-only settings
  routes/          File routes (__root.tsx is the document shell, index.tsx the chat)
  components/      Chat UI, AI Elements and shadcn/ui components
  services/        Model, instructions, Firecrawl tools, IndexedDB chat store
  lib/openrouter.ts  Supported models
```