Application example Bindings

Use KV in a real application path

Workers KV is a global key-value store for low-latency reads and lightweight shared data.

This example keeps KV simple: one binding, one fetch handler, one assertion.

The fastest way to trust a binding is to wire one small use case end to end before you hide it behind a bigger app.

Config focus: Stable namespace naming
Runtime shape: Direct and calls in a fetch handler
Best use: A tiny cache or session-marker flow

Start by wiring the binding clearly in config

Minimal KV config

import { defineConfig } from 'devflare/config'

export default defineConfig({

name: 'kv-example',

files: {

fetch: 'src/fetch.ts'

bindings: {

kv: {

CACHE: 'cache-kv'

}

})

Build the application flow around the binding

Treat this as the app-level KV 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.

Prefer a tiny route like this before you wrap KV behind a helper or service layer.

A tiny fetch handler that uses KV

import { env } from 'devflare/runtime'

export async function fetch(request: Request): Promise<Response> {

const url = new URL(request.url)

if (url.pathname === '/write') {

await env.CACHE.put('hello', 'from-kv')

return new Response('stored')

}

return new Response((await env.CACHE.get('hello')) ?? 'missing')

}

Keep production boundaries visible

Config focus: Stable namespace naming.
Runtime shape: Direct and calls in a fetch handler.
Best use: A tiny cache or session-marker flow.

Start with the boring shape

If the first KV example already feels abstract, it is probably hiding the actual binding semantics instead of teaching them.

Testing KV

Use the default test harness first. KV is one of the bindings Devflare supports best in local tests.

D1

D1 gets the same stable-name authoring story as KV, but the runtime shape is relational: , , , and prepared statements.