Overview

Val Town is a platform for writing and deploying TypeScript functions instantly — no infrastructure, no build step, no deployment pipeline. Write a function in the browser, get a URL. HTTP endpoints, cron jobs, email handlers, and persistent SQLite storage. Think "GitHub Gists that run."

When to Use

Need a quick API endpoint or webhook handler (minutes, not hours)
Scheduled tasks (cron) without managing servers
Prototyping an idea before building proper infrastructure
Webhook receivers for Stripe, GitHub, Slack integrations
Glue code between services (fetch from API A, transform, POST to API B)
Storing small amounts of data with built-in SQLite

Instructions

HTTP Val (API Endpoint)

typescript

// @user/myApi — Deployed instantly at https://user-myapi.web.val.run
export default async function(req: Request): Promise<Response> {
  const url = new URL(req.url);

  if (req.method === "GET") {
    const name = url.searchParams.get("name") || "World";
    return Response.json({ message: `Hello, ${name}!` });
  }

  if (req.method === "POST") {
    const body = await req.json();
    // Process the data
    return Response.json({ received: body, timestamp: Date.now() });
  }

  return new Response("Method not allowed", { status: 405 });
}

Cron Val (Scheduled Task)

typescript

// @user/dailyReport — Runs on a schedule
export default async function() {
  // Fetch data from an API
  const response = await fetch("https://api.example.com/stats");
  const stats = await response.json();

  // Send to Slack
  await fetch(Deno.env.get("SLACK_WEBHOOK")!, {
    method: "POST",
    body: JSON.stringify({
      text: `📊 Daily Report: ${stats.users} users, ${stats.revenue} revenue`,
    }),
  });
}

SQLite Storage

typescript

// @user/todoApi — CRUD API with persistent SQLite storage
import { sqlite } from "https://esm.town/v/std/sqlite";

// Initialize table
await sqlite.execute(`
  CREATE TABLE IF NOT EXISTS todos (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    title TEXT NOT NULL,
    done BOOLEAN DEFAULT FALSE,
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
  )
`);

export default async function(req: Request): Promise<Response> {
  const url = new URL(req.url);

  if (req.method === "GET") {
    const todos = await sqlite.execute("SELECT * FROM todos ORDER BY created_at DESC");
    return Response.json(todos.rows);
  }

  if (req.method === "POST") {
    const { title } = await req.json();
    await sqlite.execute("INSERT INTO todos (title) VALUES (?)", [title]);
    return Response.json({ ok: true }, { status: 201 });
  }

  if (req.method === "DELETE") {
    const id = url.searchParams.get("id");
    await sqlite.execute("DELETE FROM todos WHERE id = ?", [id]);
    return Response.json({ ok: true });
  }

  return new Response("Not found", { status: 404 });
}

Webhook Handler

typescript

// @user/stripeWebhook — Handle Stripe webhooks
export default async function(req: Request): Promise<Response> {
  const signature = req.headers.get("stripe-signature");
  const body = await req.text();

  // Verify webhook signature
  // In Val Town, use Deno.env.get() for secrets
  const secret = Deno.env.get("STRIPE_WEBHOOK_SECRET");

  const event = JSON.parse(body);

  switch (event.type) {
    case "checkout.session.completed":
      // Handle successful payment
      await fetch("https://api.myapp.com/activate", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ customerId: event.data.object.customer }),
      });
      break;

    case "customer.subscription.deleted":
      // Handle cancellation
      break;
  }

  return Response.json({ received: true });
}

Examples

Example 1: Quick monitoring endpoint

User prompt: "I need a quick URL that checks if my website is up and returns the status."

The agent will create an HTTP val that fetches the target URL, measures response time, and returns a JSON status report.

Example 2: GitHub webhook to Slack

User prompt: "When someone stars my GitHub repo, send a message to my Slack channel."

The agent will create an HTTP val that handles GitHub webhook events, filters for star events, and posts to a Slack webhook URL.

Guidelines

HTTP vals are standard Web API — Request in, Response out
Environment variables via Deno.env.get() — store secrets in Val Town settings
SQLite is per-account — shared across all your vals, persistent
Free tier: 10 vals, 100 cron runs/day — enough for prototyping
Import from URLs — import { x } from "https://esm.town/v/user/module"
Deno runtime — use Deno APIs, npm packages via npm:package specifier
No cold starts — vals are always warm, sub-50ms response times
Use for glue code — connect APIs, transform data, automate workflows
Not for production traffic — great for webhooks, cron, prototypes; use proper infra for high-traffic APIs

val-town

Usage

Getting Started

Example Prompts

Documentation

Overview

When to Use

Instructions

HTTP Val (API Endpoint)

Cron Val (Scheduled Task)

SQLite Storage

Webhook Handler

Examples

Example 1: Quick monitoring endpoint

Example 2: GitHub webhook to Slack

Guidelines

Information