dmmulroy

Agent prompt: fix Alchemy issue #366 and submit the PR

You are a coding agent starting with no assumed prior knowledge of Effect, Alchemy v2, Cloudflare Workers, or Durable Objects. Your job is to learn the relevant codebase conventions, reproduce alchemy-run/alchemy-effect issue #366, fix the root cause in Alchemy, add a regression test at the correct seam, and submit a pull request.

Do not treat this prompt as a substitute for investigation. Use it as a briefing and independently verify every important claim against the current repository source and a reproducible failing signal.

Outcome required

1. Clone the current upstream repository:

dmmulroy

jj-ai: AI Attribution Tracking for Jujutsu VCS

Version: 0.1.1-draft
Status: Design Specification
Date: 2026-02-03

---

Executive Summary

dmmulroy

// example-usage.ts

import { Result } from "better-result";
import { stubWithBetterResultHydration } from "./stub-with-better-result-hydration";
import type { MyDurableObject } from "./my-durable-object";

// In a Worker handler:
export default {
  async fetch(req: Request, env: Env) {
    const id = env.MY_DO.idFromName("user-123");

dmmulroy

import { DurableObjectError } from "./errors";
import { Err, Ok, Result, type Result as ResultType } from "./result";

/**
 * Adds DurableObjectError to Result error unions, wraps non-Result returns.
 * - Promise<Result<T, E>> → Promise<Result<T, E | DurableObjectError>>
 * - Promise<T> → Promise<Result<T, DurableObjectError>>
 */
type AddDOError<R> =
	R extends Promise<ResultType<infer T, infer E>>

dmmulroy

Worker Bindings Architecture

1. How env.MY_D1 Works Under the Hood

Data Flow: Configuration → C++ → JavaScript

workerd.capnp config → server.c++ (parsing) → WorkerdApi::Global → createBindingValue() → v8::Object (env)

dmmulroy

import { describe, expect, it } from "vitest";
import { AsyncResult, Result } from "./result";

describe("Ok", () => {
  it("isOk returns true", () => {
    expect(Result.ok(1).isOk()).toBe(true);
  });

  it("isErr returns false", () => {
    expect(Result.ok(1).isErr()).toBe(false);

dmmulroy

/**
 * Mixin factory for discriminated error classes with typed props.
 *
 * Props become readonly fields; `message`/`cause` auto-wire to Error; `cause.stack` chains.
 *
 * @see [TypeScript Mixins](https://www.typescriptlang.org/docs/handbook/mixins.html)
 * @typeParam Tag - Literal string for `_tag` discriminant
 * @returns Base class to extend with optional generic props
 *
 * @example

dmmulroy

import { describe, expect, it } from "vitest";
import { Result } from "./result";

describe("Ok", () => {
  it("isOk returns true", () => {
    expect(Result.ok(1).isOk()).toBe(true);
  });

  it("isErr returns false", () => {
    expect(Result.ok(1).isErr()).toBe(false);

dmmulroy

@effect/workflows: Comprehensive Technical Overview

A complete guide to durable workflow execution with Effect

Table of Contents

1. Introduction & Core Concepts
2. Core API Deep Dive
3. Advanced Features
4. Architecture & Data Flow

dmmulroy

Effect-Rx: Comprehensive Technical Overview

A complete guide to reactive state management with Effect

Table of Contents

1. Introduction & Core Concepts
2. Core API Deep Dive
3. Advanced Features
4. Framework Integrations