Edge Utils

Why you need it

• Edge handlers are fiddly to write from scratch — these are production-ready, drop-in utilities you compose into a handler.
• Security first: block AI crawlers and manage IP access with a single call.
• Lean edge code: nothing you import pulls in runtime deps, so your edge bundle stays small and fast.
• Batteries included: Wrangler ships with the package, so npx and local testing just work without a separate install.

User guide — quickstart

1. 1

   Install the package

   Add Edge Utils to the project you deploy to Contentstack Launch.

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   npm install @aryanbansal-launch/edge-utils

2. 2

   Scaffold the edge function

   Run this from your project root (where package.json lives). It creates a functions/ directory, a starter functions/[proxy].edge.js with production-ready boilerplate, and a wrangler.toml for local testing.

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   npx create-launch-edge

3. 3

   Import only what you need

   Open functions/[proxy].edge.js and pull in the specific helpers your handler uses.

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   import { blockAICrawlers, redirectIfMatch, passThrough } from "@aryanbansal-launch/edge-utils";

4. 4

   Wire your handler in order

   Call each utility in sequence. When a function returns a Response, return it immediately; otherwise keep going until passThrough(request) sends traffic on to the origin.

5. 5

   Test locally before deploying

   Run the interactive wizard to pick a preset (redirect, JSON route, basic auth, bot block, Next.js RSC), then start your app in another terminal, then start the local Wrangler dev server. Traffic flows: browser → local Worker → your handler → your running app. Open the URL Wrangler prints (typically http://localhost:8787) to test. You can also pass --port or --var BACKEND_URL to override defaults.

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   # Step 1: pick a preset and scaffold local files
   npx launch-edge-local
   
   # Step 2: start your app (in another terminal)
   npm run dev
   
   # Step 3: start the local edge worker
   npx launch-edge-test-local
   # or with overrides:
   npx launch-edge-test-local --var BACKEND_URL=http://127.0.0.1:5173

6. 6

   Manage config-driven redirects with launch-config

   For static redirects, rewrites, and cache priming URLs that don't need dynamic logic, use the interactive CLI to build a launch.json at your project root. Supports one-by-one entry or bulk import from a CSV or JSON file. You can use both launch.json and an edge function on the same project — bulk static rules in launch.json, dynamic logic (geo, cookies, A/B tests) in the edge function.

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   npx launch-config
   
   # Example CSV format for bulk import (redirects.csv):
   # source,destination,statusCode
   # /old-blog/:slug,/blog/:slug,301
   # /products/old-sku,/products/new-sku,308

7. 7

   Deploy — and get help if stuck

   Deploy the function to Contentstack Launch as usual. If you need a reminder of all available utilities and commands, run the help command.

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   npx launch-help

Under the hood

Works with: Contentstack Launch Edge Functions