Binding reference Bindings

Use Images in a Worker

Images bindings let Workers transform, resize, and encode images without public image URLs.

Add the Images config, call from worker code, and start with the local test path Devflare supports.

Start with the config, wire the binding into worker code, then use the support section to decide whether local tests or Cloudflare-backed tests fit.

Config key
Authoring shape
Best for: image transformation/upload paths where the Worker calls the Images binding

Add the binding to config

Add to , then use the generated env binding from Worker code.

Keep the first version close to the route or handler that needs it; move to a helper only after the shape is obvious.

Smallest Images config

import { defineConfig } from 'devflare/config'

export default defineConfig({

name: 'images-worker',

bindings: {

images: {

IMAGES: true

}

})

Use the binding from application code

After Devflare generates the worker env, import from and keep the first Images path close to the route, handler, or service method that needs it.

Keep this first path small enough that the config, env binding, and user-visible behavior are easy to review together.

Transform uploaded image bytes

import { env } from 'devflare/runtime'

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

if (!request.body) {

return new Response('missing image', { status: 400 })

}

return env.IMAGES

.input(request.body)

.transform({ width: 320 })

.output({ format: 'image/jpeg' })

}

Local and Remote Support

Devflare can run useful Images application behavior locally for ordinary development and tests. Cloudflare still owns production limits, quotas, billing, and deployed account behavior.

Full local support through Miniflare image bindings, persisted local state, and deterministic pure mocks. Start locally with or ; that lane should cover the normal Images application flow without requiring a Cloudflare connection.

Use Cloudflare when the assertion depends on deployed limits, account state, lifecycle behavior, billing, or other production-only Images details.

When this binding fits best

Use Images when image transformation/upload paths where the worker calls the images binding.
Keep binding names stable and uppercase in examples so generated Env declarations remain predictable.
Prefer Devflare native config while it covers the feature; use only for unsupported Wrangler-only fields.

Testing path

Start with or for config-backed local worker tests.
Use / for small unit tests that only need deterministic application behavior.
Use Cloudflare-backed tests when the assertion depends on hosted platform behavior, account state, limits, billing, or production routing.

Open the next page when you need it

Subpage

Images internals

Internals

Check emitted Wrangler , preview behavior, and Cloudflare-specific details.

Subpage

Testing Images

Testing

Pick the or path first, then move to remote checks only when the test needs them.

Subpage

Images example

Example

Copy a fuller application path when the quick example is too small.