waitUntil API

The waitUntil function allows you to schedule background tasks that will be awaited after the response is sent.

Import

import { waitUntil } from "vclight";

Usage

import { waitUntil } from "vclight";

// Schedule a background task
waitUntil(
    fetch("https://example.com/log", {
        method: "POST",
        body: JSON.stringify({ event: "user_action" })
    })
);

How it works

• Tasks are collected during request processing
• After sending the response, VCLight waits for all scheduled tasks to complete
• Platform-specific behavior:
  • Vercel Functions: Uses Vercel's waitUntil()
  • Netlify Functions: Uses Netlify's context.waitUntil()
  • Cloudflare Workers: Uses Cloudflare's ctx.waitUntil()
  • Node HTTP / Vercel Node: Waits directly

Example: Logging after response

import VCLight from "vclight";
import { waitUntil } from "vclight";

const app = new VCLight();

app.use({
    async process(_request, response) {
        response.response = "OK";
        
        // Schedule log after response
        waitUntil(
            logEvent("request_processed", {
                status: response.status,
                timestamp: new Date().toISOString()
            })
        );
    },
    async post() {}
});

async function logEvent(event: string, data: any) {
    return fetch("https://logs.example.com/api/events", {
        method: "POST",
        body: JSON.stringify({ event, data })
    });
}