Binding reference Bindings

Use Media Transformations in a Worker

Media Transformations bindings let Workers transform video or audio from protected sources.

Add the Media Transformations 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: video/audio transformation paths where the Worker calls Cloudflare Media Transformations

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 Media Transformations config

import { defineConfig } from 'devflare/config'

export default defineConfig({

name: 'media-worker',

bindings: {

media: {

MEDIA: true

}

})

Use the binding from application code

After Devflare generates the worker env, import from and keep the first Media Transformations 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.

Run one media transformation chain

import { env } from 'devflare/runtime'

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

if (!request.body) {

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

}

return env.MEDIA

.input(request.body)

.transform({ width: 640 })

.output({ format: 'video/mp4' })

}

Local and Remote Support

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

Full local support through Miniflare media bindings and deterministic pure mocks for transform chains. Start locally with or with media fixtures; that lane should cover the normal Media Transformations 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 Media Transformations details.

When this binding fits best

Use Media Transformations when video/audio transformation paths where the worker calls cloudflare media transformations.
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 with media fixtures 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

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Media Transformations internals

Internals

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

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Testing Media Transformations

Testing

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

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Media Transformations example

Example

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