Val Town Code SearchReturn to Val Town

8## Hono
9
10This app uses [Hono](https://hono.dev/) as the API framework. You can think of Hono as a replacement for [ExpressJS](https://expressjs.com/) that works in serverless environments like Val Town or Cloudflare Workers. If you come from Python or Ruby, Hono is also a lot like [Flask](https://github.com/pallets/flask) or [Sinatra](https://github.com/sinatra/sinatra), respectively.
11
12## Serving assets to the frontend
20### `index.html`
21
22The most complicated part of this backend API is serving index.html. In this app (like most apps) we serve it at the root, ie `GET /`. 
23
24We *bootstrap* `index.html` with some initial data from the server, so that it gets dynamically injected JSON data without having to make another round-trip request to the server to get that data on the frontend. This is a common pattern for client-side rendered apps.
25
26## CRUD API Routes
27
28This app has two CRUD API routes: for reading and inserting into the messages table. They both speak JSON, which is standard. They import their functions from `/backend/database/queries.ts`. These routes are called from the React app to refresh and update data.
29
30## Errors
31
32Hono and other API frameworks have a habit of swallowing up Errors. We turn off this default behavior by re-throwing errors, because we think most of the time you'll want to see the full stack trace instead of merely "Internal Server Error". You can customize how you want errors to appear.

8import { type Memory } from "../../shared/types.ts";
9
10const API_BASE = "/api/memories";
11const MEMORIES_PER_PAGE = 20;
12
71    setError(null);
72    try {
73      const response = await fetch(API_BASE);
74      if (!response.ok) {
75        throw new Error(`HTTP error! status: ${response.status}`);
100
101    try {
102      const response = await fetch(API_BASE, {
103        method: "POST",
104        headers: { "Content-Type": "application/json" },
123
124    try {
125      const response = await fetch(`${API_BASE}/${id}`, {
126        method: "DELETE",
127      });
155
156    try {
157      const response = await fetch(`${API_BASE}/${editingMemory.id}`, {
158        method: "PUT",
159        headers: { "Content-Type": "application/json" },

18});
19
20// --- API Routes for Memories ---
21
22// GET /api/memories - Retrieve all memories
23app.get("/api/memories", async (c) => {
24  const memories = await getAllMemories();
25  return c.json(memories);
26});
27
28// POST /api/memories - Create a new memory
29app.post("/api/memories", async (c) => {
30  const body = await c.req.json<Omit<Memory, "id">>();
31  if (!body.text) {
36});
37
38// PUT /api/memories/:id - Update an existing memory
39app.put("/api/memories/:id", async (c) => {
40  const id = c.req.param("id");
41  const body = await c.req.json<Partial<Omit<Memory, "id">>>();
58});
59
60// DELETE /api/memories/:id - Delete a memory
61app.delete("/api/memories/:id", async (c) => {
62  const id = c.req.param("id");
63  try {
75// --- Blob Image Serving Routes ---
76
77// GET /api/images/:filename - Serve images from blob storage
78app.get("/api/images/:filename", async (c) => {
79  const filename = c.req.param("filename");
80

85  console.log(e.text);
86
87  // Get Anthropic API key from environment
88  const apiKey = Deno.env.get("ANTHROPIC_API_KEY");
89  if (!apiKey) {
90    console.error("Anthropic API key is not configured for this val.");
91    return;
92  }
93
94  // Initialize Anthropic client
95  const anthropic = new Anthropic({ apiKey });
96
97  // Process each image attachment serially

92
93/**
94 * Format chat history for Anthropic API
95 */
96function formatChatHistoryForAI(history) {
321bot.on("message", async (ctx) => {
322  try {
323    // Get Anthropic API key from environment
324    const apiKey = Deno.env.get("ANTHROPIC_API_KEY");
325    if (!apiKey) {
326      console.error("Anthropic API key is not configured.");
327      ctx.reply(
328        "I apologize, but I'm not properly configured at the moment. Please inform the household administrator."
332
333    // Initialize Anthropic client
334    const anthropic = new Anthropic({ apiKey });
335
336    // Get message text and user info
502  // Set webhook if it is not set yet
503  if (!isEndpointSet) {
504    await bot.api.setWebhook(req.url, {
505      secret_token: SECRET_TOKEN,
506    });

27async function generateConciseWeatherSummary(weatherDay) {
28  try {
29    // Get API key from environment
30    const apiKey = Deno.env.get("ANTHROPIC_API_KEY");
31    if (!apiKey) {
32      console.error("Anthropic API key is not configured.");
33      return null;
34    }
35
36    // Initialize Anthropic client
37    const anthropic = new Anthropic({ apiKey });
38
39    const response = await anthropic.messages.create({

77async function generateFunFacts(previousFacts) {
78  try {
79    // Get API key from environment
80    const apiKey = Deno.env.get("ANTHROPIC_API_KEY");
81    if (!apiKey) {
82      console.error("Anthropic API key is not configured.");
83      return null;
84    }
85
86    // Initialize Anthropic client
87    const anthropic = new Anthropic({ apiKey });
88
89    // Format previous facts for the prompt

20### 2. HTTP Vals
21
22- Create web APIs and endpoints
23- Handle HTTP requests and responses
24- Example structure:
66- Generate code in TypeScript
67- Add appropriate TypeScript types and interfaces for all data structures
68- Prefer official SDKs or libraries than writing API calls directly
69- Ask the user to supply API or library documentation if you are at all unsure about it
70- **Never bake in secrets into the code** - always use environment variables
71- Include comments explaining complex logic (avoid commenting obvious operations)
190- For AI-generated images, use: `https://maxm-imggenurl.web.val.run/the-description-of-your-image`
191- **Storage:** DO NOT use the Deno KV module for storage
192- **Browser APIs:** DO NOT use the `alert()`, `prompt()`, or `confirm()` methods
193- **Weather Data:** Use open-meteo for weather data (doesn't require API keys) unless otherwise specified
194- **View Source:** Add a view source link with `import.meta.url.replace("esm.town", "val.town")` and include `target="_top"` attribute
195- **Error Debugging:** Add `<script src="https://esm.town/v/std/catch"></script>` to HTML to capture client-side errors
196- **Error Handling:** Only use try...catch when there's a clear local resolution; avoid catches that merely log or return 500s - let errors bubble up with full context
197- **Environment Variables:** Use `Deno.env.get('keyname')` and minimize their use - prefer APIs without keys
198- **Imports:** Use `https://esm.sh` for npm and Deno dependencies to ensure compatibility on server and browser
199- **Storage Strategy:** Only use backend storage if explicitly required; prefer simple static client-side sites
230
231### Backend (Hono) Best Practices
232- Hono is the recommended API framework (similar to Express, Flask, or Sinatra)
233- Main entry point should be `backend/index.ts`
234- **Static asset serving:** Use the utility functions to read and serve project files:
251  });
252  ```
253- Create RESTful API routes for CRUD operations
254- Be careful with error handling as Hono tends to swallow errors
255- Always include this snippet at the top-level Hono app to re-throwing errors to see full stack traces:
268- Use React 18.2.0 consistently in all imports and the `@jsxImportSource` pragma
269- Follow the React component pattern from the example project
270- Handle API calls properly with proper error catching
271
272### Database Patterns
299   - For files in the project, use `readFile` helpers
300
3015. **API Design:**
302   - `fetch` handler is the entry point for HTTP vals
303   - Run the Hono app with `export default app.fetch // This is the entry point for HTTP vals`

10import { NotebookView } from "./NotebookView.tsx";
11
12const API_BASE = "/api/memories";
13const MEMORIES_PER_PAGE = 20; // Increased from 7 to 20 memories per page
14
90
91    // Fetch avatar image
92    fetch("/api/images/stevens.jpg")
93      .then((response) => {
94        if (response.ok) return response.blob();
104
105    // Fetch wood background
106    fetch("/api/images/wood.jpg")
107      .then((response) => {
108        if (response.ok) return response.blob();
133    setError(null);
134    try {
135      const response = await fetch(API_BASE);
136      if (!response.ok) {
137        throw new Error(`HTTP error! status: ${response.status}`);
176
177    try {
178      const response = await fetch(API_BASE, {
179        method: "POST",
180        headers: { "Content-Type": "application/json" },
199
200    try {
201      const response = await fetch(`${API_BASE}/${id}`, {
202        method: "DELETE",
203      });
231
232    try {
233      const response = await fetch(`${API_BASE}/${editingMemory.id}`, {
234        method: "PUT",
235        headers: { "Content-Type": "application/json" },
606    <div className="font-pixel text-[#f8f1e0]">
607      <style jsx>{`
608        @import url("https://fonts.googleapis.com/css2?family=Pixelify+Sans&display=swap");
609
610        @tailwind base;

1import { z } from "https://deno.land/x/zod@v3.22.4/mod.ts";
2import type { FC } from "npm:hono/jsx";
3
4export interface Options {
5  homepage?: FC;