Application example Bindings

Use Durable Objects in a real application path

Durable Objects give Workers a named place for stateful coordination, storage, and alarms.

A real Durable Objects application path with config and runtime code kept side by side.

Use this as the application-focused Durable Objects example before you add feature-specific abstractions around the binding.

Config focus: Auto-discovered file plus one DO binding
Runtime shape: Durable Objects calls from worker application code
Best use: Counters, room state, and small single-identity coordination examples

Start by wiring the binding clearly in config

Minimal Durable Object config using the default discovery pattern

import { defineConfig } from 'devflare/config'

export default defineConfig({

name: 'do-example',

files: {

fetch: 'src/fetch.ts'

bindings: {

durableObjects: {

COUNTER: 'Counter'

}

migrations: [

{

tag: 'v1',

new_classes: ['Counter']

}

]

})

// Devflare auto-discovers src/do.counter.ts via the default:

// durableObjects: '**/do.*.{ts,js}'

Build the application flow around the binding

Treat this as the app-level Durable Objects path: the route, event handler, or service module receives a real request and uses the binding to do useful work.

Keep product limits, remote ownership, and fallback behavior visible in the code around the binding instead of hiding everything behind a vague utility too early.

This tiny shape already proves that the object class, namespace, storage, and worker path are wired correctly.
Once this works, richer room, session, or lock logic becomes a normal extension instead of a blind leap.

A tiny object and one worker path

import { DurableObject } from 'cloudflare:workers'

export class Counter extends DurableObject<DevflareEnv> {

async increment(amount = 1): Promise<number> {

const current = (await this.ctx.storage.get<number>('value')) ?? 0

const next = current + amount

await this.ctx.storage.put('value', next)

return next

}

async getValue(): Promise<number> {

return (await this.ctx.storage.get<number>('value')) ?? 0

}

Keep production boundaries visible

Config focus: Auto-discovered file plus one DO binding.
Runtime shape: Durable Objects calls from worker application code.
Best use: Counters, room state, and small single-identity coordination examples.

Testing Durable Objects

Durable Objects are well-supported in the default Devflare harness, which means you can test real object behavior without hand-building a fake namespace first.

Queues

Devflare models Queue producers and consumers explicitly, which makes local tests and preview naming much easier to reason about.