> ## Documentation Index > Fetch the complete documentation index at: https://docs.windrose.market/llms.txt > Use this file to discover all available pages before exploring further. # Web app > Build and run the Next.js app, wire it to an indexer per chain, and understand what gates the chain switcher. The app in `apps/web` is a Next.js App Router project using wagmi, viem, TanStack Query and RainbowKit. It serves every chain that has a deployment file at once; the top-bar switcher picks one and every hook and component reads that chain's RPC, addresses and indexer through `useChain()`. ## Environment `apps/web/.env.example` documents every variable. `NEXT_PUBLIC_*` values are inlined at build time, so rebuild after changing any of them. | Variable | Default | Meaning | | -------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `NEXT_PUBLIC_CHAIN_ID` | `46630` | The *default* chain: what a first visit shows when nothing is remembered and no `?chain=` is in the URL, and the only chain the unsuffixed variables below apply to. | | `NEXT_PUBLIC_RPC_URL_` | the registry `rpc` | RPC per chain. Point one at a local anvil that mimics the chain, for instance `NEXT_PUBLIC_RPC_URL_46630=http://127.0.0.1:8545`. | | `NEXT_PUBLIC_RPC_URL` | | RPC override for the default chain only. | | `NEXT_PUBLIC_INDEXER_URL_` | none | That chain's Ponder GraphQL endpoint. The browser calls it, so it must be the public URL. A chain without its own variable shows on-chain data and "indexer offline" rather than another chain's index. | | `NEXT_PUBLIC_INDEXER_URL` | `http://localhost:42069` in development | Indexer for the default chain only. | | `NEXT_PUBLIC_MULTICALL3` | unset (probe at runtime) | Force a Multicall3 address for batched reads, or `none` to skip the probe. Applies to every chain. | | `NEXT_PUBLIC_FACTORY`, `NEXT_PUBLIC_ROUTER`, `NEXT_PUBLIC_REGISTRY`, `NEXT_PUBLIC_STATE_VIEW`, `NEXT_PUBLIC_USDC`, `NEXT_PUBLIC_USDC_SYMBOL` | unset | Fallback addresses for the default chain when its deployment file is absent. | | `DEPLOYMENTS_DIR` | `packages/abis/deployments` (resolved through the workspace symlink or relative to the app) | Directory containing `.json` when it lives elsewhere. Server-side only. | | `NEXT_PUBLIC_SHOW_TESTNETS` | testnets shown when the default chain is one | `1` lists the testnets in the switcher of a mainnet build. | | `NEXT_PUBLIC_WALLETCONNECT_PROJECT_ID` | unset | WalletConnect Cloud project id. Without it only injected (browser extension) wallets are offered. | | `NEXT_PUBLIC_DOCS_URL` | `https://docs.windrose.market` | Where the Docs links in the rail and footer, the "How it works" tile and the `/guide` redirect point. | ## Build and start ```bash theme={"system"} pnpm --filter @launchpad/web build # runs scripts/gen-abis.mjs, eslint, next build pnpm --filter @launchpad/web start # next start (port 3000) ``` `pnpm dev` and `pnpm build` both start with `scripts/gen-abis.mjs`, which re-emits the JSON ABIs from `@launchpad/abis` as `as const` TypeScript (`src/lib/abis.generated.ts`, plus a union of every custom error so nested reverts decode) and writes `src/lib/chains.generated.ts` with the ids of the chains that have a deployment file. Run `pnpm --filter @launchpad/web gen` on its own after `pnpm abis` changes the ABIs. On the production box pm2 runs the JS entry directly, because pnpm's `.bin` shims are shell scripts: ```js theme={"system"} { name: "windrose-web", cwd: "apps/web", script: "node_modules/next/dist/bin/next", args: "start -p 3000", env: { NODE_ENV: "production" }, max_memory_restart: "500M", } ``` After changing `apps/web/.env.local`: rebuild, then `pm2 restart windrose-web`. If the build gets killed for lack of memory while three indexers backfill, stop one (`pm2 stop windrose-indexer-arc`), build, start it again. ## Which chains appear Three things decide what the switcher offers: 1. **A deployment file at build time.** `scripts/gen-abis.mjs` scans `packages/abis/deployments/*.json` and bakes the chain ids into `src/lib/chains.generated.ts`; the wagmi config registers those chains when the module loads. Add a file, rebuild. 2. **Testnet visibility.** A mainnet default hides testnets unless `NEXT_PUBLIC_SHOW_TESTNETS=1`. A testnet default lists everything. 3. **Coming soon.** In a mainnet build, registry mainnets without a deployment (Arc, 5042, today) are listed as "Coming soon" and disabled. `GET /api/chains` re-checks the files on every request so the UI can annotate a chain whose file appeared after the server started, and `GET /api/deployment?chainId=` reads the addresses lazily (falling back to the `NEXT_PUBLIC_*` addresses for the default chain). Both are documented under [HTTP endpoints](/api). Next.js only inlines literal `process.env.NEXT_PUBLIC_*` reads, so a chain id needs a row in both `RPC_ENV` and `INDEXER_ENV` of `apps/web/src/lib/chain.ts` before `NEXT_PUBLIC_RPC_URL_` and `NEXT_PUBLIC_INDEXER_URL_` work in the browser. Add the rows when you [add a chain](/operate/add-a-chain). ## Copy driven by the registry Everything that names the dollar, the chain, the gas token or the faucet comes from `packages/abis/chains.json` through `useChain()`: "Gas is paid in ETH", "Get test USDG", the faucet link, explorer links. Brand strings ("Windrose") are not. The dollar's logo is `dollar.logo` from the registry or `/tokens/.svg`; the `CoinLogo` component falls back to initials when the file is missing. ## Token logos and token lists ```bash theme={"system"} CHAIN_ID=4663 pnpm abis:logos # one SVG per synthetic currency in apps/web/public/tokens/ TOKEN_LOGO_BASE=https://windrose.market/tokens/ CHAIN_ID=4663 pnpm abis:tokenlist # Uniswap Token List in packages/abis/tokenlist/ ``` `abis:logos` never overwrites an existing `USDC.svg` or `EURC.svg` unless `--force` is passed. `abis:tokenlist` reads names, symbols and decimals from the chain (falling back to the deployment file and `Currencies.sol` with `--offline`), names the file after the registry key (`robinhood.tokenlist.json`) and bumps the version per the token-list rules, so re-running is a no-op when nothing changed. The naming prefixes of the coins are read back from the deployment file (`synthNamePrefix`, `synthSymbolPrefix`). ## SEO files * `/og.png` is the Open Graph image referenced by the root metadata. * `robots.ts` allows everything except `/api/` and points at the sitemap. * `sitemap.ts` lists the static pages plus one currency page (`/c/`) per registered currency of the default chain, read from its deployment file, and revalidates hourly. ## Docs links The Docs entry in the rail, the footer link and the "How it works" tile open `NEXT_PUBLIC_DOCS_URL` in a new tab, and `/guide` (the old in-app docs page) redirects there, so bookmarks keep working. The docs are hosted by Mintlify at `docs.windrose.market` and live in `apps/docs` of this repository; see [Self-hosting](/operate/self-hosting) for the DNS shape.