| 1 | --- |
| 2 | title: "Part 4: A Vite Frontend" |
| 3 | description: Connect a Vite frontend to your Prisma API, develop locally, and destroy the tutorial resources. |
| 4 | sidebar: |
| 5 | order: 4 |
| 6 | --- |
| 7 | |
| 8 | import { Code, Tabs, TabItem } from "@astrojs/starlight/components"; |
| 9 | |
| 10 | Continue from [Part 3](/prisma/tutorial/part-3). Add a browser button that |
| 11 | queries the API, then run the frontend locally against the deployed backend. |
| 12 | |
| 13 | ## Install the frontend tooling |
| 14 | |
| 15 | <Tabs syncKey="pkgManager"> |
| 16 | <TabItem label="bun" icon="bun"><Code code="bun add -d vite @vercel/nft" lang="sh" /></TabItem> |
| 17 | <TabItem label="npm" icon="npm"><Code code="npm install -D vite @vercel/nft" lang="sh" /></TabItem> |
| 18 | <TabItem label="pnpm" icon="pnpm"><Code code="pnpm add -D vite @vercel/nft" lang="sh" /></TabItem> |
| 19 | <TabItem label="yarn" icon="seti:yarn"><Code code="yarn add -D vite @vercel/nft" lang="sh" /></TabItem> |
| 20 | </Tabs> |
| 21 | |
| 22 | Vite builds the frontend. `@vercel/nft` traces the server dependencies that |
| 23 | Alchemy includes in the deployment archive. |
| 24 | |
| 25 | ## Allow the frontend origin |
| 26 | |
| 27 | The frontend and API have separate origins. Add a response-header variable |
| 28 | inside the API's `fetch` Effect: |
| 29 | |
| 30 | ```diff lang="typescript" |
| 31 | // src/Api.ts |
| 32 | const request = yield* HttpServerRequest; |
| 33 | + const headers = { "access-control-allow-origin": "*" }; |
| 34 | ``` |
| 35 | |
| 36 | This tutorial exposes only a public, read-only timestamp query. For a real |
| 37 | application, restrict allowed origins and add authentication before exposing |
| 38 | private data. CORS is a browser policy, not an authorization mechanism. |
| 39 | |
| 40 | ## Attach the response headers |
| 41 | |
| 42 | ```diff lang="typescript" |
| 43 | // src/Api.ts |
| 44 | status: 405, |
| 45 | - headers: { allow: "GET" }, |
| 46 | + headers: { ...headers, allow: "GET" }, |
| 47 | |
| 48 | - return yield* HttpServerResponse.json({ ok: true }); |
| 49 | + return yield* HttpServerResponse.json({ ok: true }, { headers }); |
| 50 | |
| 51 | - return yield* HttpServerResponse.json(rows[0]); |
| 52 | + return yield* HttpServerResponse.json(rows[0], { headers }); |
| 53 | |
| 54 | - return HttpServerResponse.text("Not found", { status: 404 }); |
| 55 | + return HttpServerResponse.text("Not found", { status: 404, headers }); |
| 56 | |
| 57 | status: 503, |
| 58 | + headers: { "access-control-allow-origin": "*" }, |
| 59 | ``` |
| 60 | |
| 61 | All explicitly constructed API responses now use the same CORS policy. |
| 62 | The frontend sends a simple GET without credentials or custom headers. |
| 63 | |
| 64 | ## Create the page |
| 65 | |
| 66 | Create `index.html` in the project root: |
| 67 | |
| 68 | ```html |
| 69 | <!doctype html> |
| 70 | <html lang="en"> |
| 71 | <head> |
| 72 | <meta charset="UTF-8" /> |
| 73 | <meta name="viewport" content="width=device-width, initial-scale=1.0" /> |
| 74 | <title>Prisma tutorial</title> |
| 75 | </head> |
| 76 | <body> |
| 77 | <main> |
| 78 | <h1>Prisma database clock</h1> |
| 79 | <p>Read the current time from Prisma Postgres through an Effect API.</p> |
| 80 | <button id="refresh" type="button">Read database time</button> |
| 81 | <p id="result" role="status">No query yet.</p> |
| 82 | </main> |
| 83 | <script type="module" src="/src/main.ts"></script> |
| 84 | </body> |
| 85 | </html> |
| 86 | ``` |
| 87 | |
| 88 | The status element announces query results, while the button gives the user |
| 89 | control over when to send a request. |
| 90 | |
| 91 | ## Query from the browser |
| 92 | |
| 93 | Create `src/main.ts`: |
| 94 | |
| 95 | ```typescript |
| 96 | const button = document.querySelector<HTMLButtonElement>("#refresh")!; |
| 97 | const result = document.querySelector<HTMLParagraphElement>("#result")!; |
| 98 | |
| 99 | button.addEventListener("click", async () => { |
| 100 | button.disabled = true; |
| 101 | result.textContent = "Querying Postgres…"; |
| 102 | try { |
| 103 | const response = await fetch(`${import.meta.env.VITE_API_URL}/api/time`); |
| 104 | if (!response.ok) throw new Error(`Request failed (${response.status})`); |
| 105 | const data: { time: string } = await response.json(); |
| 106 | result.textContent = `Database time: ${data.time}`; |
| 107 | } catch { |
| 108 | result.textContent = "Could not read the database. Please try again."; |
| 109 | } finally { |
| 110 | button.disabled = false; |
| 111 | } |
| 112 | }); |
| 113 | ``` |
| 114 | |
| 115 | The button is disabled during the request and re-enabled after either success |
| 116 | or failure. `VITE_API_URL` will contain a public API URL, never a database |
| 117 | credential. If your editor needs Vite's `import.meta.env` types, add |
| 118 | `/// <reference types="vite/client" />` to `src/vite-env.d.ts`. |
| 119 | |
| 120 | ## Keep the backend remote during development |
| 121 | |
| 122 | ```diff lang="typescript" |
| 123 | // alchemy.run.ts |
| 124 | - const project = yield* Project; |
| 125 | - const api = yield* Api; |
| 126 | + const project = yield* Project.pipe(Alchemy.remote()); |
| 127 | + const api = yield* Api.pipe(Alchemy.remote()); |
| 128 | ``` |
| 129 | |
| 130 | `Alchemy.remote()` keeps this backend on Prisma when running `alchemy dev`. |
| 131 | It is a no-op during deployment. This tutorial deliberately uses real |
| 132 | Postgres during frontend development, so credentials and cloud charges still |
| 133 | apply. The Project is also remote because it is shared with the website. |
| 134 | |
| 135 | ## Add the website |
| 136 | |
| 137 | ```diff lang="typescript" |
| 138 | // alchemy.run.ts |
| 139 | const api = yield* Api.pipe(Alchemy.remote()); |
| 140 | + const site = yield* Prisma.Website.Vite("Website", { |
| 141 | + project, |
| 142 | + regionId: "eu-west-3", |
| 143 | + env: { VITE_API_URL: api.url }, |
| 144 | + }); |
| 145 | - return { projectId: project.projectId, apiUrl: api.url }; |
| 146 | + return { url: site.url, apiUrl: api.url }; |
| 147 | ``` |
| 148 | |
| 149 | The website uses the same Project. Its environment references the API output, |
| 150 | so Alchemy resolves the API URL before building the frontend. `VITE_` values |
| 151 | are embedded in the public browser bundle; only put public configuration there. |
| 152 | |
| 153 | ## Deploy the frontend |
| 154 | |
| 155 | <Tabs syncKey="pkgManager"> |
| 156 | <TabItem label="bun" icon="bun"><Code code="bun alchemy deploy" lang="sh" /></TabItem> |
| 157 | <TabItem label="npm" icon="npm"><Code code="npx alchemy deploy" lang="sh" /></TabItem> |
| 158 | <TabItem label="pnpm" icon="pnpm"><Code code="pnpm exec alchemy deploy" lang="sh" /></TabItem> |
| 159 | <TabItem label="yarn" icon="seti:yarn"><Code code="yarn alchemy deploy" lang="sh" /></TabItem> |
| 160 | </Tabs> |
| 161 | |
| 162 | Open `url` and click **Read database time**. The response should display a |
| 163 | Postgres timestamp. Click again to execute a new query. |
| 164 | |
| 165 | ## Develop locally |
| 166 | |
| 167 | <Tabs syncKey="pkgManager"> |
| 168 | <TabItem label="bun" icon="bun"><Code code="bun alchemy dev" lang="sh" /></TabItem> |
| 169 | <TabItem label="npm" icon="npm"><Code code="npx alchemy dev" lang="sh" /></TabItem> |
| 170 | <TabItem label="pnpm" icon="pnpm"><Code code="pnpm exec alchemy dev" lang="sh" /></TabItem> |
| 171 | <TabItem label="yarn" icon="seti:yarn"><Code code="yarn alchemy dev" lang="sh" /></TabItem> |
| 172 | </Tabs> |
| 173 | |
| 174 | Open the local website URL that Alchemy prints. Edit the heading and confirm |
| 175 | Vite updates the page. Click the button to query the remote API. Provider-mode |
| 176 | changes can replace the deployed website with its local counterpart in this |
| 177 | stage; use a separate `--stage dev` when you want to keep a production site. |
| 178 | A separate stage creates its own remote backend resources too. |
| 179 | |
| 180 | ## Remove the resources |
| 181 | |
| 182 | Stop the dev command, then destroy the Stack: |
| 183 | |
| 184 | <Tabs syncKey="pkgManager"> |
| 185 | <TabItem label="bun" icon="bun"><Code code="bun alchemy destroy" lang="sh" /></TabItem> |
| 186 | <TabItem label="npm" icon="npm"><Code code="npx alchemy destroy" lang="sh" /></TabItem> |
| 187 | <TabItem label="pnpm" icon="pnpm"><Code code="pnpm exec alchemy destroy" lang="sh" /></TabItem> |
| 188 | <TabItem label="yarn" icon="seti:yarn"><Code code="yarn alchemy destroy" lang="sh" /></TabItem> |
| 189 | </Tabs> |
| 190 | |
| 191 | Confirm the deletion. This removes the website, API, connection, database, and |
| 192 | Project. Use the same profile and stage used to deploy; destroy every extra |
| 193 | stage you created. Keep `.alchemy/` until cleanup completes so Alchemy can |
| 194 | find the resources it owns. |
| 195 | |
| 196 | ## Where to go next |
| 197 | |
| 198 | - [Complete tutorial example](https://github.com/alchemy-run/alchemy/tree/main/examples/prisma-tutorial) |
| 199 | - [Frontend frameworks](/prisma/frontend/websites) — Astro, Next.js, and the other Website helpers. |
| 200 | - [Postgres](/prisma/data/postgres) — database configuration and local development. |
| 201 | - [Connections](/prisma/data/connections) — runtime connection bindings. |
| 202 | - [Compute apps](/prisma/compute/apps) — deployment options and custom domains. |