CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

This is a Val Town project that implements a likes tracking API using unique IDs with the following structure:

• Val Town Platform: Built for Val Town's serverless environment using Deno runtime
• Backend: Hono web framework with SQLite database for ID-based likes tracking
• API Service: RESTful endpoints with CORS support for cross-origin requests
• Entry Point: index.ts exports app.fetch as the HTTP handler

• Uses Val Town's hosted SQLite service (stevekrouse/sqlite)
• Table name: likes_by_id_v1 (increment version when changing schema)
• Core functions: initDatabase(), recordLike(), getAllLikes(), getLikeCount(), getTotalLikes()
• Database tracks likes by unique ID (string identifier)
• Schema: id (TEXT PRIMARY KEY), likes (INTEGER), created_at, updated_at
• Database initializes automatically on startup

• Self-contained HTML documentation and demo page
• Interactive testing interface for all API endpoints
• Code examples for integration
• Styled with custom CSS for professional appearance

• Hono app with error unwrapping for debugging and CORS support
• Routes: / (documentation page), POST /api/like (record like), GET /api/likes/:id (get count for specific ID), GET /api/likes (all data)
• Accepts JSON payloads with id field (string)
• Returns updated like counts for real-time UI updates

# Run/test the application locally
deno run --allow-net --allow-read index.ts

# Lint code
deno lint

# Format code  
deno fmt

# Type checking
deno check index.ts

When modifying the database schema, increment the table name (e.g., likes_by_id_v1 → likes_by_id_v2) rather than using ALTER TABLE operations.

The API is designed for cross-origin requests. Example usage from any website:

// Record a like for a specific content ID
fetch("https://your-val-url.val.run/api/like", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    id: "post-123", // Any unique identifier
  }),
})
  .then((res) => res.json())
  .then((data) => console.log("New like count:", data.likeCount));

// Get like count for a specific ID
fetch("https://your-val-url.val.run/api/likes/post-123")
  .then((res) => res.json())
  .then((data) => console.log("Like count:", data.likeCount));

Uses Val Town utility functions for proper file serving:

import {
  readFile,
  serveFile,
} from "https://esm.town/v/std/utils@85-main/index.ts";

Include this pattern in Hono apps for better error visibility:

app.onError((err, c) => {
  throw err;
});

The API includes CORS headers to allow requests from any origin:

app.use(
  "*",
  cors({
    origin: "*",
    allowMethods: ["GET", "POST", "OPTIONS"],
    allowHeaders: ["Content-Type"],
  }),
);

• TypeScript: Configured with relaxed settings (noImplicitAny: false, strict: false)
• Imports: Uses https://esm.sh for npm packages and https://esm.town/v/ for Val Town utilities
• Styling: TailwindCSS via CDN script tag
• Error Debugging: Includes <script src="https://esm.town/v/std/catch"></script> for client-side error capture