RPC transforms

@durability/transforms composes cross-cutting behavior around Cloudflare Durable Object and Worker service-binding RPC. Transforms can run at the caller, callee, or both while preserving target compatibility and transformed async return types.

npm install @durability/transforms

Caller

Bound wait time, retry idempotent calls, decode values, or attach metadata.

Callee

Observe calls, apply policy, consume context, or encode results.

Typed chains

.with() validates the target, options, context, and resulting method type.

Native RPC

Context travels through Cloudflare RPC promise pipelining, not a custom protocol.

Vite setup

The plugin reads validated Wrangler bindings, wraps matching RPC stubs, and generates declarations that add .with() to their types.

import { doTransforms } from '@durability/transforms/vite';
import { defineConfig } from 'vite';

export default defineConfig({
  plugins: [
    doTransforms({ wrangler: './wrangler.jsonc' }),
  ],
});

The declaration defaults to do-transforms.generated.d.ts beside the Wrangler main module. Include it in the application’s TypeScript project. When using Cloudflare’s Vite plugin, place doTransforms() before cloudflare().

Apply built-ins

import { retry, timeout } from '@durability/transforms';

const report = await env.REPORTS.getByName(id)
  .with(timeout, 5_000)
  .with(retry, { retries: 3 })
  .load();

Caution

A caller timeout does not stop remote work, and every retry is a new RPC invocation. Retry only idempotent methods or include an idempotency key.

Continue with authoring transforms, built-ins, or the API reference.