Built-in transforms

Timeout

timeout rejects the caller with CallerTimeoutError after a deadline:

const value = await stub.with(timeout, 5_000).read();

The error includes method and timeoutMs. Remote work is not cancelled.

Retry

retry repeats failed RPC calls sequentially. Its count is retries after the first call:

const value = await stub.with(retry, {
  retries: 3,
  delay: ({ error, attempt }) => {
    console.warn('retrying', { error, attempt });
    return Math.min(1_000 * 2 ** (attempt - 1), 30_000);
  },
}).read();

Without delay, it uses capped exponential backoff with full jitter. A numeric shorthand is supported:

stub.with(retry, 3);

Better Result codec

Register betterResultCodec on the callee and apply it on the caller to serialize and rehydrate better-result values in a versioned envelope:

applyTransforms(MyObject, {
  all: [registerTransform(betterResultCodec)],
});

const result = await stub.with(betterResultCodec).read();

Version 0.1.0 payloads are rejected by default because their unmarked shape is ambiguous. During a migration only:

stub.with(betterResultCodec, { acceptLegacy: true });

Error boundary

errorBoundary converts values and caller-visible throws to Better Results:

const result = await stub.with(errorBoundary).read();

Abort as success

abortAsSuccess converts Cloudflare errors marked durableObjectReset to Result.ok(undefined) and preserves other throws. Use it only when resetting the object is an expected success condition.

Large-object transfer

largeObjectStream transfers bounded JSON object results over a marked ReadableStream. Configure the callee and require a Standard Schema validator at the caller:

applyTransforms(MyObject, {
  methods: {
    snapshot: [
      registerTransform(largeObjectStream, {
        thresholdBytes: 1_000_000,
        maxEncodeBytes: 8 * 1024 * 1024,
      }),
    ],
  },
});

const snapshot = await stub.with(largeObjectStream, {
  schema: snapshotSchema,
  maxDecodeBytes: 8 * 1024 * 1024,
}).snapshot();

Defaults are a 1 MiB streaming threshold and 8 MiB encode/decode limits. Existing ReadableStream values pass through unchanged.

Limit and validation failures throw LargeObjectEncodeLimitError, LargeObjectDecodeLimitError, or LargeObjectValidationError.