\n \n\n\n",[],[99,214],{"_104":222,"_95":223,"_153":224,"_155":208,"_156":138,"_157":225,"_159":22,"_106":226,"_100":32,"_162":227,"_164":228,"_165":22,"_166":-5,"_167":229,"_98":230},"b1f07900-4c64-11f0-8c80-76b3cceeab13","index.js","b1f079e6-4c64-11f0-8c80-76b3cceeab13",20,["D",1750265581368],"script","// Simulate the upstream plugin host system\nclass PluginHost {\n constructor() {\n this.hooks = new Map();\n }\n \n register(component, hooks) {\n const list = this.hooks.get(component) || [];\n list.push(hooks);\n this.hooks.set(component, list);\n console.log(`🔌 Plugin registered for ${component}:`, hooks);\n }\n \n getHooks(component) {\n return this.hooks.get(component) || [];\n }\n}\n\n// Global plugin host instance\nconst pluginHost = new PluginHost();\n\n// Upstream Widget Component (simulated)\nclass UpstreamWidget {\n constructor(container) {\n this.container = container;\n this.state = { count: 0 };\n this.hooks = pluginHost.getHooks('Widget');\n \n // Allow plugins to mutate initial state\n for (const hook of this.hooks) {\n if (hook.beforeInit) {\n this.state = hook.beforeInit(this.state);\n }\n }\n \n this.render();\n this.mount();\n }\n \n mount() {\n // Call mounted hooks\n for (const hook of this.hooks) {\n if (hook.mounted) {\n hook.mounted({ \n state: this.state, \n update: (patch) => this.update(patch) \n });\n }\n }\n }\n \n update(patch) {\n this.state = { ...this.state, ...patch };\n this.render();\n \n // Call updated hooks\n for (const hook of this.hooks) {\n if (hook.updated) {\n hook.updated({ state: this.state });\n }\n }\n }\n \n render() {\n this.container.innerHTML = `\n

🔵 Upstream Widget

beforeInit hooks: ${this.hooks.filter(h => h.beforeInit).length}

\n \n

mounted/updated hooks: ${this.hooks.filter(h => h.mounted || h.updated).length}

\n State: ${JSON.stringify(this.state)}\n

\n `;\n }\n}\n\n// Downstream Plugins (your customizations)\nconsole.log('🚀 Registering downstream plugins...');\n\n// Plugin 1: Analytics\npluginHost.register('Widget', {\n beforeInit: (state) => {\n console.log('📊 Analytics: Initializing with state:', state);\n return { ...state, analyticsEnabled: true };\n },\n mounted: ({ state }) => {\n console.log('📊 Analytics: Widget mounted with state:', state);\n },\n updated: ({ state }) => {\n console.log('📊 Analytics: Widget updated, count =', state.count);\n // Simulate sending metrics\n if (state.count > 0) {\n console.log('📊 Sending metric: button_click_count =', state.count);\n }\n }\n});\n\n// Plugin 2: Customization\npluginHost.register('Widget', {\n beforeInit: (state) => {\n console.log('🎨 Customization: Setting default count to 42');\n return { ...state, count: 42, customized: true };\n },\n mounted: ({ state, update }) => {\n console.log('🎨 Customization: Adding auto-increment feature');\n // Auto-increment every 3 seconds as a demo\n setTimeout(() => {\n if (state.count < 50) {\n update({ count: state.count + 1 });\n }\n }, 3000);\n }\n});\n\n// Initialize the app\ndocument.addEventListener('DOMContentLoaded', () => {\n const app = document.getElementById('app');\n \n app.innerHTML = `\n

🔌 Plugin Host Architecture Demo

\n \n

Concept Overview

\n This demonstrates the plugin host pattern for managing upstream/downstream changes.\n The upstream widget provides extension points, and downstream plugins customize behavior.\n

\n \n

🟢 Downstream Plugins Registered

📊 Analytics Plugin: Tracks widget interactions
🎨 Customization Plugin: Sets default count to 42, adds auto-increment

\n \n

Check the browser console to see plugin hooks firing! 🔍

Initial data: ${JSON.stringify(window.__INITIAL_DATA__ || {})}

\n \n

How it works:

Upstream widget defines hook points (beforeInit, mounted, updated)
Downstream plugins register with the plugin host
Widget calls hooks at appropriate lifecycle moments
Plugins can modify state, add behavior, send analytics, etc.
Upstream changes don't break downstream customizations

\n `;\n \n // Create the widget instance\n const widgetContainer = document.getElementById('widget-container');\n window.widget = new UpstreamWidget(widgetContainer);\n \n console.log('✅ App initialized with plugin architecture');\n});\n",[],[99,223],[99],{"_104":233,"_95":234,"_153":235,"_155":-5,"_156":138,"_157":236,"_159":22,"_106":237,"_100":32,"_162":163,"_164":-5,"_165":22,"_166":-5,"_167":238,"_98":248},"b1d18d1a-4c64-11f0-9722-76b3cceeab13","shared","b1d18df6-4c64-11f0-9722-76b3cceeab13",17,["D",1750265581217],[239],{"_104":240,"_95":241,"_153":242,"_155":235,"_156":138,"_157":243,"_159":22,"_106":244,"_100":32,"_162":227,"_164":245,"_165":22,"_166":-5,"_167":246,"_98":247},"b1f3fd14-4c64-11f0-b099-76b3cceeab13","types.ts","b1f3fdd2-4c64-11f0-b099-76b3cceeab13",21,["D",1750265581368],"// Shared types for the plugin host architecture\n\nexport interface PluginHooks {\n beforeInit?: (state: T) => T;\n mounted?: (ctx: { state: T; update: (next: Partial) => void }) => void;\n updated?: (ctx: { state: T }) => void;\n}\n\nexport interface WidgetState {\n count: number;\n analyticsEnabled?: boolean;\n customized?: boolean;\n [key: string]: any;\n}\n\nexport interface PluginHost {\n register(component: string, hooks: PluginHooks): void;\n getHooks(component: string): PluginHooks[];\n}\n\nexport interface UpstreamInfo {\n version: string;\n component: string;\n hookPoints: string[];\n}\n",[],[234,241],[234],{"_104":250,"_95":251,"_153":252,"_155":-5,"_156":138,"_157":253,"_159":160,"_106":254,"_100":32,"_162":182,"_164":255,"_165":22,"_166":-5,"_167":256,"_98":257},"b28ca890-43ed-11f0-8c3a-76b3cceeab13",".cursorrules","b28ca94e-43ed-11f0-8c3a-76b3cceeab13",4,["D",1749334863030],"You are an advanced assistant specialized in generating Val Town code.\n\n## Core Guidelines\n\n- Ask clarifying questions when requirements are ambiguous\n- Provide complete, functional solutions rather than skeleton implementations\n- Test your logic against edge cases before presenting the final solution\n- Ensure all code follows Val Town's specific platform requirements\n- If a section of code that you're working on is getting too complex, consider refactoring it into subcomponents\n\n## Code Standards\n\n- Generate code in TypeScript or TSX\n- Add appropriate TypeScript types and interfaces for all data structures\n- Prefer official SDKs or libraries than writing API calls directly\n- Ask the user to supply API or library documentation if you are at all unsure about it\n- **Never bake in secrets into the code** - always use environment variables\n- Include comments explaining complex logic (avoid commenting obvious operations)\n- Follow modern ES6+ conventions and functional programming practices if possible\n\n## Types of triggers\n\n### 1. HTTP Trigger\n\n- Create web APIs and endpoints\n- Handle HTTP requests and responses\n- Example structure:\n\n```ts\nexport default async function (req: Request) {\n return new Response(\"Hello World\");\n}\n```\n\nFiles that are HTTP triggers have http in their name like `foobar.http.tsx`\n\n### 2. Cron Triggers\n\n- Run on a schedule\n- Use cron expressions for timing\n- Example structure:\n\n```ts\nexport default async function () {\n // Scheduled task code\n}\n```\n\nFiles that are Cron triggers have cron in their name like `foobar.cron.tsx`\n\n### 3. Email Triggers\n\n- Process incoming emails\n- Handle email-based workflows\n- Example structure:\n\n```ts\nexport default async function (email: Email) {\n // Process email\n}\n```\n\nFiles that are Email triggers have email in their name like `foobar.email.tsx`\n\n\n## Val Town Standard Libraries\n\nVal Town provides several hosted services and utility functions.\n\n### Blob Storage\n\n```ts\nimport { blob } from \"https://esm.town/v/std/blob\";\nawait blob.setJSON(\"myKey\", { hello: \"world\" });\nlet blobDemo = await blob.getJSON(\"myKey\");\nlet appKeys = await blob.list(\"app_\");\nawait blob.delete(\"myKey\");\n```\n\n### SQLite\n\n```ts\nimport { sqlite } from \"https://esm.town/v/stevekrouse/sqlite\";\nconst TABLE_NAME = 'todo_app_users_2';\n// Create table - do this before usage and change table name when modifying schema\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS ${TABLE_NAME} (\n id INTEGER PRIMARY KEY AUTOINCREMENT,\n name TEXT NOT NULL\n)`);\n// Query data\nconst result = await sqlite.execute(`SELECT * FROM ${TABLE_NAME} WHERE id = ?`, [1]);\n```\n\nNote: When changing a SQLite table's schema, change the table's name (e.g., add _2 or _3) to create a fresh table.\n\n### OpenAI\n\n```ts\nimport { OpenAI } from \"https://esm.town/v/std/openai\";\nconst openai = new OpenAI();\nconst completion = await openai.chat.completions.create({\n messages: [\n { role: \"user\", content: \"Say hello in a creative way\" },\n ],\n model: \"gpt-4o-mini\",\n max_tokens: 30,\n});\n```\n\n### Email\n\n```ts\nimport { email } from \"https://esm.town/v/std/email\";\n// By default emails the owner of the val\nawait email({ \n subject: \"Hi\", \n text: \"Hi\", \n html: \"

Hi

\"\n});\n```\n\n## Val Town Utility Functions\n\nVal Town provides several utility functions to help with common project tasks.\n\n### Importing Utilities\n\nAlways import utilities with version pins to avoid breaking changes:\n\n```ts\nimport { parseProject, readFile, serveFile } from \"https://esm.town/v/std/utils@85-main/index.ts\";\n```\n\n### Available Utilities\n\n\n#### **serveFile** - Serve project files with proper content types\n\nFor example, in Hono:\n\n```ts\n// serve all files in frontend/ and shared/\napp.get(\"/frontend/*\", c => serveFile(c.req.path, import.meta.url));\napp.get(\"/shared/*\", c => serveFile(c.req.path, import.meta.url));\n```\n\n#### **readFile** - Read files from within the project:\n\n```ts\n// Read a file from the project\nconst fileContent = await readFile(\"/frontend/index.html\", import.meta.url);\n```\n\n#### **listFiles** - List all files in the project\n\n```ts\nconst files = await listFiles(import.meta.url);\n```\n\n#### **parseProject** - Extract information about the current project from import.meta.url\n\nThis is useful for including info for linking back to a val, ie in \"view source\" urls:\n\n```ts\nconst projectVal = parseProject(import.meta.url);\nconsole.log(projectVal.username); // Owner of the project\nconsole.log(projectVal.name); // Project name\nconsole.log(projectVal.version); // Version number\nconsole.log(projectVal.branch); // Branch name\nconsole.log(projectVal.links.self.project); // URL to the project page\n```\n\nHowever, it's *extremely importing* to note that `parseProject` and other Standard Library utilities ONLY RUN ON THE SERVER.\nIf you need access to this data on the client, run it in the server and pass it to the client by splicing it into the HTML page\nor by making an API request for it.\n\n## Val Town Platform Specifics\n\n- **Redirects:** Use `return new Response(null, { status: 302, headers: { Location: \"/place/to/redirect\" }})` instead of `Response.redirect` which is broken\n- **Images:** Avoid external images or base64 images. Use emojis, unicode symbols, or icon fonts/libraries instead\n- **AI Image:** To inline generate an AI image use: `

`\n- **Storage:** DO NOT use the Deno KV module for storage\n- **Browser APIs:** DO NOT use the `alert()`, `prompt()`, or `confirm()` methods\n- **Weather Data:** Use open-meteo for weather data (doesn't require API keys) unless otherwise specified\n- **View Source:** Add a view source link by importing & using `import.meta.url.replace(\"ems.sh\", \"val.town)\"` (or passing this data to the client) and include `target=\"_top\"` attribute\n- **Error Debugging:** Add `` to HTML to capture client-side errors\n- **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\n- **Environment Variables:** Use `Deno.env.get('keyname')` when you need to, but generally prefer APIs that don't require keys\n- **Imports:** Use `https://esm.sh` for npm and Deno dependencies to ensure compatibility on server and browser\n- **Storage Strategy:** Only use backend storage if explicitly required; prefer simple static client-side sites\n- **React Configuration:** When using React libraries, pin versions with `?deps=react@18.2.0,react-dom@18.2.0` and start the file with `/** @jsxImportSource https://esm.sh/react@18.2.0 */`\n- Ensure all React dependencies and sub-dependencies are pinned to the same version\n- **Styling:** Default to using TailwindCSS via `` unless otherwise specified\n\n## Project Structure and Design Patterns\n\n### Recommended Directory Structure\n```\n├── backend/\n│ ├── database/\n│ │ ├── migrations.ts # Schema definitions\n│ │ ├── queries.ts # DB query functions\n│ │ └── README.md\n│ └── routes/ # Route modules\n│ ├── [route].ts\n│ └── static.ts # Static file serving\n│ ├── index.ts # Main entry point\n│ └── README.md\n├── frontend/\n│ ├── components/\n│ │ ├── App.tsx\n│ │ └── [Component].tsx\n│ ├── favicon.svg\n│ ├── index.html # Main HTML template\n│ ├── index.tsx # Frontend JS entry point\n│ ├── README.md\n│ └── style.css\n├── README.md\n└── shared/\n ├── README.md\n └── utils.ts # Shared types and functions\n```\n\n### Backend (Hono) Best Practices\n\n- Hono is the recommended API framework\n- Main entry point should be `backend/index.ts`\n- **Static asset serving:** Use the utility functions to read and serve project files:\n ```ts\n import { readFile, serveFile } from \"https://esm.town/v/std/utils@85-main/index.ts\";\n \n // serve all files in frontend/ and shared/\n app.get(\"/frontend/*\", c => serveFile(c.req.path, import.meta.url));\n app.get(\"/shared/*\", c => serveFile(c.req.path, import.meta.url));\n \n // For index.html, often you'll want to bootstrap with initial data\n app.get(\"/\", async c => {\n let html = await readFile(\"/frontend/index.html\", import.meta.url);\n \n // Inject data to avoid extra round-trips\n const initialData = await fetchInitialData();\n const dataScript = ``;\n \n html = html.replace(\"\", `${dataScript}`);\n return c.html(html);\n });\n ```\n- Create RESTful API routes for CRUD operations\n- Always include this snippet at the top-level Hono app to re-throwing errors to see full stack traces:\n ```ts\n // Unwrap Hono errors to see original error details\n app.onError((err, c) => {\n throw err;\n });\n ```\n\n### Database Patterns\n- Run migrations on startup or comment out for performance\n- Change table names when modifying schemas rather than altering\n- Export clear query functions with proper TypeScript typing\n\n## Common Gotchas and Solutions\n\n1. **Environment Limitations:** \n - Val Town runs on Deno in a serverless context, not Node.js\n - Code in `shared/` must work in both frontend and backend environments\n - Cannot use `Deno` keyword in shared code\n - Use `https://esm.sh` for imports that work in both environments\n\n2. **SQLite Peculiarities:**\n - Limited support for ALTER TABLE operations\n - Create new tables with updated schemas and copy data when needed\n - Always run table creation before querying\n\n3. **React Configuration:**\n - All React dependencies must be pinned to 18.2.0\n - Always include `@jsxImportSource https://esm.sh/react@18.2.0` at the top of React files\n - Rendering issues often come from mismatched React versions\n\n4. **File Handling:**\n - Val Town only supports text files, not binary\n - Use the provided utilities to read files across branches and forks\n - For files in the project, use `readFile` helpers\n\n5. **API Design:**\n - `fetch` handler is the entry point for HTTP vals\n - Run the Hono app with `export default app.fetch // This is the entry point for HTTP vals`\n\n",[],[251],{"_104":259,"_95":260,"_153":261,"_155":-5,"_156":138,"_157":262,"_159":160,"_106":263,"_100":32,"_162":182,"_164":264,"_165":22,"_166":-5,"_167":265,"_98":266},"b28fbddc-43ed-11f0-a32e-76b3cceeab13",".vtignore","b28fbf4e-43ed-11f0-a32e-76b3cceeab13",5,["D",1749334863039],".git\n.vscode\n.DS_Store\nnode_modules\nvendor\n",[],[260],{"_104":268,"_95":269,"_153":270,"_155":-5,"_156":138,"_157":271,"_159":22,"_106":272,"_100":32,"_162":182,"_164":273,"_165":22,"_166":-5,"_167":274,"_98":275},"b1ec4bdc-4c64-11f0-b5cf-76b3cceeab13","README.md","b1ec4c72-4c64-11f0-b5cf-76b3cceeab13",19,["D",1750265581375],"# Plugin Host Architecture Demo\n\nThis Val Town project demonstrates the plugin host pattern for managing upstream/downstream changes in a modular application architecture.\n\n## 🎯 Problem Solved\n\nWhen you have a fork of an existing full-stack app that you need to customize while keeping up with upstream changes, traditional approaches create maintenance headaches. This pattern provides a clean solution.\n\n## 🔧 Architecture\n\n### Upstream (Library/Framework)\n- **Plugin Host**: Central registry for extension points\n- **Hook Points**: Defined lifecycle moments where plugins can inject behavior\n- **Stable API**: Typed interfaces that don't break with updates\n\n### Downstream (Your Application)\n- **Plugins**: Modular customizations that register with hook points\n- **Clean Separation**: Your code lives outside the upstream subtree\n- **Future-Proof**: Upstream updates don't break your customizations\n\n## 🚀 Demo Features\n\n1. **Widget Component**: Simulated upstream component with plugin hooks\n2. **Analytics Plugin**: Tracks interactions and sends metrics\n3. **Customization Plugin**: Modifies default behavior and adds features\n4. **Live Console**: Watch plugin hooks fire in real-time\n\n## 🔍 Key Benefits\n\n- ✅ **Maintainable**: Clear separation between upstream and downstream code\n- ✅ **Testable**: Plugin contracts are explicit and typed\n- ✅ **Flexible**: Add new plugins without modifying upstream code\n- ✅ **Trackable**: Use git subtree to track upstream SHA, not just version strings\n- ✅ **Conflict-Free**: Merge conflicts only occur at hook layer boundaries\n\n## 🛠 Implementation Pattern\n\n```typescript\n// 1. Upstream defines hook points\nconst hooks = pluginHost.getHooks('ComponentName');\nfor (const hook of hooks) {\n state = hook.beforeInit?.(state) ?? state;\n}\n\n// 2. Downstream registers plugins\npluginHost.register('ComponentName', {\n beforeInit: (state) => ({ ...state, customField: true }),\n mounted: ({ state, update }) => console.log('Mounted!'),\n updated: ({ state }) => sendAnalytics(state)\n});\n```\n\n## 📁 Project Structure\n\n```\n├── backend/ # Hono server\n├── frontend/ # Client-side demo\n├── shared/ # Shared types and utilities\n└── README.md # This file\n```\n\n## 🎮 Try It Out\n\n1. Click the widget button to see plugins in action\n2. Open browser console to watch hook execution\n3. Notice how plugins modify behavior without touching upstream code\n\nThis pattern scales from simple customizations to complex enterprise integrations while maintaining clean boundaries and upgrade paths.\n",[],[269],{"_104":277,"_95":278,"_153":279,"_155":-5,"_156":138,"_157":280,"_159":160,"_106":281,"_100":32,"_162":182,"_164":282,"_165":22,"_166":-5,"_167":283,"_98":284},"b282456c-43ed-11f0-9f99-76b3cceeab13","deno.json","b2824634-43ed-11f0-9f99-76b3cceeab13",3,["D",1749334862958],"{\n \"$schema\": \"https://raw.githubusercontent.com/denoland/deno/348900b8b79f4a434cab4c74b3bc8d4d2fa8ee74/cli/schemas/config-file.v1.json\",\n \"lock\": false,\n \"compilerOptions\": {\n \"noImplicitAny\": false,\n \"strict\": false,\n \"types\": [\n \"https://www.val.town/types/valtown.d.ts\"\n ],\n \"lib\": [\n \"dom\",\n \"dom.iterable\",\n \"dom.asynciterable\",\n \"deno.ns\",\n \"deno.unstable\"\n ]\n },\n \"lint\": {\n \"files\": {\n \"include\": [\n \"deno:/https/esm.town/**/*\"\n ]\n },\n \"rules\": {\n \"exclude\": [\n \"no-explicit-any\"\n ]\n }\n },\n \"node_modules_dir\": false,\n \"experimental\": {\n \"unstable-node-globals\": true,\n \"unstable-temporal\": true,\n \"unstable-worker-options\": true,\n \"unstable-sloppy-imports\": true\n }\n}",[],[278],{"_104":286,"_95":287,"_153":288,"_155":-5,"_156":138,"_157":289,"_159":22,"_106":290,"_100":262,"_162":182,"_164":291,"_165":22,"_166":-5,"_167":292,"_98":293},"0dbc2240-4c63-11f0-9fe3-76b3cceeab13","knowledge.md","b27c439c-43ed-11f0-a32e-76b3cceeab13",13,["D",1750264876429],"You are an advanced assistant specialized in generating Val Town code.\n\n## Core Guidelines\n\n- Ask clarifying questions when requirements are ambiguous\n- Provide complete, functional solutions rather than skeleton implementations\n- Test your logic against edge cases before presenting the final solution\n- Ensure all code follows Val Town's specific platform requirements\n- If a section of code that you're working on is getting too complex, consider refactoring it into subcomponents\n- If a file has an export that can be used with a trigger, do not move the stable.\n\n## Code Standards\n\n- Generate code in TypeScript or TSX\n- Add appropriate TypeScript types and interfaces for all data structures\n- Prefer official SDKs or libraries than writing API calls directly\n- Ask the user to supply API or library documentation if you are at all unsure about it\n- **Never bake in secrets into the code** - always use environment variables\n- Include comments explaining complex logic (avoid commenting obvious operations)\n- Follow modern ES6+ conventions and functional programming practices if possible\n\n## Types of triggers\n\n### 1. HTTP Trigger\n\n- Create web APIs and endpoints\n- Handle HTTP requests and responses\n- Example structure:\n\n```ts\nexport default async function (req: Request) {\n return new Response(\"Hello World\");\n}\n```\n\nFiles that are HTTP triggers have http in their name like `foobar.http.tsx`\n\n### 2. Cron Triggers\n\n- Run on a schedule\n- Use cron expressions for timing\n- Example structure:\n\n```ts\nexport default async function () {\n // Scheduled task code\n}\n```\n\nFiles that are Cron triggers have cron in their name like `foobar.cron.tsx`\n\n### 3. Email Triggers\n\n- Process incoming emails\n- Handle email-based workflows\n- Example structure:\n\n```ts\nexport default async function (email: Email) {\n // Process email\n}\n```\n\nFiles that are Email triggers have email in their name like `foobar.email.tsx`\n\n\n## Val Town Standard Libraries\n\nVal Town provides several hosted services and utility functions.\n\n### Blob Storage\n\n```ts\nimport { blob } from \"https://esm.town/v/std/blob\";\nawait blob.setJSON(\"myKey\", { hello: \"world\" });\nlet blobDemo = await blob.getJSON(\"myKey\");\nlet appKeys = await blob.list(\"app_\");\nawait blob.delete(\"myKey\");\n```\n\n### SQLite\n\n```ts\nimport { sqlite } from \"https://esm.town/v/stevekrouse/sqlite\";\nconst TABLE_NAME = 'todo_app_users_2';\n// Create table - do this before usage and change table name when modifying schema\nawait sqlite.execute(`CREATE TABLE IF NOT EXISTS ${TABLE_NAME} (\n id INTEGER PRIMARY KEY AUTOINCREMENT,\n name TEXT NOT NULL\n)`);\n// Query data\nconst result = await sqlite.execute(`SELECT * FROM ${TABLE_NAME} WHERE id = ?`, [1]);\n```\n\nNote: When changing a SQLite table's schema, change the table's name (e.g., add _2 or _3) to create a fresh table.\n\n#### Batching operations\n\n```ts\nimport { sqlite } from \"https://esm.town/v/std/sqlite\";\n\nconst charge = 10;\n\nexport const batchSqlite = await sqlite.batch([\n `create table if not exists accounts(person_id text unique, balance integer)`,\n {\n sql: `update accounts set balance = balance - :charge where person_id = 'Bob'`,\n args: { charge },\n },\n {\n sql: `update accounts set balance = balance + :charge where person_id = 'Alice'`,\n args: { charge },\n },\n]);\n```\n\n### OpenAI\n\n```ts\nimport { OpenAI } from \"https://esm.town/v/std/openai\";\nconst openai = new OpenAI();\nconst completion = await openai.chat.completions.create({\n messages: [\n { role: \"user\", content: \"Say hello in a creative way\" },\n ],\n model: \"gpt-4o-mini\",\n max_tokens: 30,\n});\n```\n\n### Email\n\n```ts\nimport { email } from \"https://esm.town/v/std/email\";\n// By default emails the owner of the val\nawait email({ \n subject: \"Hi\", \n text: \"Hi\", \n html: \"

Hi

`\n- **Storage:** DO NOT use the Deno KV module for storage\n- **Browser APIs:** DO NOT use the `alert()`, `prompt()`, or `confirm()` methods\n- **Weather Data:** Use open-meteo for weather data (doesn't require API keys) unless otherwise specified\n- **View Source:** Add a view source link by importing & using `import.meta.url.replace(\"ems.sh\", \"val.town)\"` (or passing this data to the client) and include `target=\"_top\"` attribute\n- **Error Debugging:** Add `` to HTML to capture client-side errors\n- **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\n- **Environment Variables:** Use `Deno.env.get('keyname')` when you need to, but generally prefer APIs that don't require keys\n- **Imports:** Use `https://esm.sh` for npm and Deno dependencies to ensure compatibility on server and browser\n- **Storage Strategy:** Only use backend storage if explicitly required; prefer simple static client-side sites\n- **React Configuration:** When using React libraries, pin versions with `?deps=react@18.2.0,react-dom@18.2.0` and start the file with `/** @jsxImportSource https://esm.sh/react@18.2.0 */`\n- Ensure all React dependencies and sub-dependencies are pinned to the same version\n- **Styling:** Default to using TailwindCSS via `` unless otherwise specified\n\n## Project Structure and Design Patterns\n\n### Recommended Directory Structure\n```\n├── backend/\n│ ├── database/\n│ │ ├── migrations.ts # Schema definitions\n│ │ ├── queries.ts # DB query functions\n│ │ └── README.md\n│ └── routes/ # Route modules\n│ ├── [route].ts\n│ └── static.ts # Static file serving\n│ ├── index.ts # Main entry point\n│ └── README.md\n├── frontend/\n│ ├── components/\n│ │ ├── App.tsx\n│ │ └── [Component].tsx\n│ ├── favicon.svg\n│ ├── index.html # Main HTML template\n│ ├── index.tsx # Frontend JS entry point\n│ ├── README.md\n│ └── style.css\n├── README.md\n└── shared/\n ├── README.md\n └── utils.ts # Shared types and functions\n```\n\n### Backend (Hono) Best Practices\n\n- Hono is the recommended API framework\n- Main entry point should be `backend/index.ts`\n- **Static asset serving:** Use the utility functions to read and serve project files:\n ```ts\n import { readFile, serveFile } from \"https://esm.town/v/std/utils@85-main/index.ts\";\n \n // serve all files in frontend/ and shared/\n app.get(\"/frontend/*\", c => serveFile(c.req.path, import.meta.url));\n app.get(\"/shared/*\", c => serveFile(c.req.path, import.meta.url));\n \n // For index.html, often you'll want to bootstrap with initial data\n app.get(\"/\", async c => {\n let html = await readFile(\"/frontend/index.html\", import.meta.url);\n \n // Inject data to avoid extra round-trips\n const initialData = await fetchInitialData();\n const dataScript = ``;\n \n html = html.replace(\"\", `${dataScript}`);\n return c.html(html);\n });\n ```\n- Create RESTful API routes for CRUD operations\n- Always include this snippet at the top-level Hono app to re-throwing errors to see full stack traces:\n ```ts\n // Unwrap Hono errors to see original error details\n app.onError((err, c) => {\n throw err;\n });\n ```\n\n### Database Patterns\n- Run migrations on startup or comment out for performance\n- Change table names when modifying schemas rather than altering\n- Export clear query functions with proper TypeScript typing\n\n## Common Gotchas and Solutions\n\n1. **Environment Limitations:** \n - Val Town runs on Deno in a serverless context, not Node.js\n - Code in `shared/` must work in both frontend and backend environments\n - Cannot use `Deno` keyword in shared code\n - Use `https://esm.sh` for imports that work in both environments\n\n2. **SQLite Peculiarities:**\n - Limited support for ALTER TABLE operations\n - Create new tables with updated schemas and copy data when needed\n - Always run table creation before querying\n\n3. **React Configuration:**\n - All React dependencies must be pinned to 18.2.0\n - Always include `@jsxImportSource https://esm.sh/react@18.2.0` at the top of React files\n - Rendering issues often come from mismatched React versions\n\n4. **File Handling:**\n - Val Town only supports text files, not binary\n - Use the provided utilities to read files across branches and forks\n - For files in the project, use `readFile` helpers\n\n5. **API Design:**\n - `fetch` handler is the entry point for HTTP vals\n - Run the Hono app with `export default app.fetch // This is the entry point for HTTP vals`",[],[287],{"_104":295,"_95":296,"_153":297,"_155":-5,"_156":138,"_157":298,"_159":22,"_106":299,"_100":32,"_162":182,"_164":300,"_165":22,"_166":-5,"_167":301,"_98":302},"6ba8182c-4c64-11f0-b195-76b3cceeab13","learning_goal.md","6ba8191c-4c64-11f0-b195-76b3cceeab13",14,["D",1750265463503],"# Learning Project\n\nThe goal is to explore an idea.\n\n## Context\n\nI have a task. I'm a senior developer. There's an app that uses a fork of an existing app, and the existing app is a full-stack app, not modularized. It's not intended to be customized, but the wrapper app is customizing it nevertheless. The challenge is that we would like to both keep up with upstream changes and be freely able to change the files we're working on. It's using Svelte, so this is a bit difficult. We surveyed our options.\n\n## Best option\n\nSmall permanent fork that injects formal extension points, then merge upstream as a git subtree. • You fork once to add an official PluginHost with typed hooks/events. • Upstream’s future commits are pulled into the subtree; conflicts surface only where the hook layer lives. • Your product repo contains only plug-ins, themes, and routes.\n\nThe hook contract is explicit & testable—avoids “alias drift.” Subtree lets you track upstream SHA, not just a version string, so you can cherry-pick bug-fixes quickly.\nRequires initial negotiation (or brute-force) to land hooks upstream. Subtree UX in Git is less familiar than submodules; team needs a short how-to.\n\n// upstream/src/lib/pluginHost.ts ← (tiny, permanent fork)\nimport { setContext, getContext } from 'svelte';\n\ntype ScriptHooks = {\n\tbeforeInit?: (state: T) => T;\n\tmounted?: (ctx: { state: T; update: (next: Partial) => void }) => void;\n\tupdated?: (ctx: { state: T }) => void;\n};\n\nconst key = Symbol('plugin-bus');\n\nexport function initPluginBus() {\n\tconst map = new Map();\n\tsetContext(key, {\n\t\tregister(component: string, hooks: ScriptHooks) {\n\t\t\tconst list = map.get(component) ?? [];\n\t\t\tlist.push(hooks);\n\t\t\tmap.set(component, list);\n\t\t},\n\t\tget(component: string) {\n\t\t\treturn map.get(component) ?? [];\n\t\t}\n\t});\n}\n\nexport function scriptHooksFor(component: string): ScriptHooks[] {\n\treturn getContext<{ get: (c: string) => ScriptHooks[] }>(key).get(component);\n}\n\n\n\n\n\n\n// product/plugins/widget-analytics.ts ← lives *outside* the subtree\nimport { scriptHooksFor } from 'upstream/lib/pluginHost'; // re-export in your barrel\n\n// register at app start-up\nimport '$lib/bootstrap/plugins'; // e.g. in main.ts\n\n// product/src/bootstrap/plugins.ts\nimport { initPluginBus } from 'upstream/lib/pluginHost';\nconst bus = initPluginBus();\n\nbus.register('Widget', {\n\tbeforeInit: s => ({ ...s, count: 42 }), // default to 42\n\tmounted : ({ state }) => console.log('mount', state),\n\tupdated : ({ state }) => sendMetric(state.count) // analytics\n});\n\n## How to explore the idea?\n\n\"Simulate\" the upstream and downstream as folders.\nUpstream is import mapped so that it can be importent \"as if a package @deepend\".\nDownstream is imported locally.\n\nUse Svelte.\n\n## Dependencies\n\n@sveltejs/adapter-auto: 3.2.2\n@sveltejs/adapter-static: ^3.0.2\n@sveltejs/kit: ^2.5.20\n@sveltejs/vite-plugin-svelte: ^3.1.1\n@tailwindcss/container-queries: ^0.1.1\n@tailwindcss/postcss: ^4.0.0\n@tailwindcss/typography: ^0.5.13\n@typescript-eslint/eslint-plugin: ^8.31.1\n@typescript-eslint/parser: ^8.31.1\ncypress: ^13.15.0\neslint: ^8.56.0\neslint-config-prettier: ^9.1.0\neslint-plugin-cypress: ^3.4.0\neslint-plugin-svelte: ^2.43.0\ni18next-parser: ^9.0.1\npostcss: ^8.4.31\nprettier: ^3.3.3\nprettier-plugin-svelte: ^3.2.6\nsass-embedded: ^1.81.0\nsvelte: ^4.2.18\nsvelte-check: ^3.8.5\nsvelte-confetti: ^1.3.2\ntailwindcss: ^4.0.0\ntslib: ^2.4.1\ntypescript: ^5.5.4\nvite: ^5.4.14\nvitest: 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