Edge Functions

V8-based lightweight functions running at the edge. Ideal for simple APIs, KV storage access, and ultra-low latency responses.

> Runtime: V8 (like Cloudflare Workers) — NOT Node.js. Do NOT use Node.js built-ins or npm packages. > > ⚠️ Response.json() is NOT available in this V8 runtime. Always use new Response(JSON.stringify(data), { headers: { 'Content-Type': 'application/json' } }) instead.

Basic function

File: edge-functions/api/hello.js

javascript
export default function onRequest(context) {
  return new Response('Hello from Edge Functions!');
}

Access: GET /api/hello

HTTP method handlers

javascript
// edge-functions/api/users.js

// Handle all methods
export function onRequest(context) {
  return new Response('Any method');
}

// Or use specific method handlers:
export function onRequestGet(context) {
  return new Response(JSON.stringify({ users: [] }), {
    headers: { 'Content-Type': 'application/json' },
  });
}

export async function onRequestPost(context) {
  const body = await context.request.json();
  return new Response(JSON.stringify({ created: true }), {
    status: 201,
    headers: { 'Content-Type': 'application/json' },
  });
}

EventContext object

javascript
export function onRequest(context) {
  const {
    request,    // Standard Request object
    params,     // Dynamic route params, e.g. { id: "123" }
    env,        // Environment variables from Makers console
    waitUntil,  // Extend function lifetime for async tasks
  } = context;

  // GEO info available via:
  const geo = context.request.eo;
  // geo.geo.countryName, geo.geo.cityName, geo.geo.latitude, etc.

  return new Response('OK');
}

Dynamic routes

javascript
// edge-functions/api/users/[id].js
// Matches: /api/users/123, /api/users/abc

export function onRequestGet(context) {
  const userId = context.params.id;
  return new Response(JSON.stringify({ userId }), {
    headers: { 'Content-Type': 'application/json' },
  });
}

javascript
// edge-functions/api/[[default]].js
// Catches all unmatched routes under /api/

export function onRequest(context) {
  return new Response('Catch-all route', { status: 404 });
}

KV Storage (Edge Functions only)

> Cross-reference: if your code uses context.store or KV APIs, also read skills/makers-storage/SKILL.md.

⚠️ Prerequisites: You must enable KV Storage in the EdgeOne Makers console, create a namespace, and bind it to your project before using KV. See kv-storage.md for full setup instructions (same directory).

The KV namespace is a global variable (name is set when binding in the console) — it is NOT on context.env.

javascript
// edge-functions/api/counter.js

export async function onRequest(context) {
  // ⚠️ my_kv is a GLOBAL variable (name set when binding namespace in console)
  // Do NOT use context.env.KV ❌
  
  // Read
  const count = await my_kv.get('page_views') || '0';
  const newCount = parseInt(count) + 1;

  // Write
  await my_kv.put('page_views', String(newCount));

  return new Response(JSON.stringify({ views: newCount }), {
    headers: { 'Content-Type': 'application/json' },
  });
}

For full KV Storage API reference and usage guide, see: kv-storage.md (same directory).

Supported Runtime APIs

Edge Functions run on V8 and support these Web Standard APIs:

• Fetch API — fetch() for outbound HTTP requests
• Cache API — caches.open(), cache.match(), cache.put()
• Headers / Request / Response — standard Web API objects
• Streams — ReadableStream, WritableStream, TransformStream
• Web Crypto — crypto.subtle for encryption/signing
• Encoding — TextEncoder, TextDecoder
• URL / URLSearchParams — URL parsing

⚠️ NOT available: Node.js built-ins (fs, path, http, crypto from Node), require(), npm packages.

Limits

| Resource | Limit | |----------|-------| | Code package size | 5 MB | | Request body | 1 MB | | CPU time per invocation | 200 ms | | Language | JavaScript (ES2023+) only |