Shopify

Build me a small self-hosted shop for a handful of products, the honest small
slice of Shopify. Requirements:

- Node + Express + better-sqlite3 on a VPS; products in products.json (slug,
  name, price, images, stock count), server-rendered catalog and product pages.
- Cart in a session cookie; checkout hands off entirely to Stripe Checkout
  (keys in .env). Never touch card data.
- Stripe webhook records the order, decrements stock, and emails me and the
  buyer via Resend (key in .env).
- An /admin page behind basic auth: order list and a mark-shipped button that
  emails the buyer with an optional tracking number.
- Flat shipping rates per region in a config file; sold-out products stay
  visible but cannot be bought.
- No customer accounts, no telemetry; orders stay in my SQLite file.
- Out of scope: discount engines, multi-currency, POS, and tax automation. Use
  Stripe Tax for tax; do not write tax logic.
- README: Stripe webhook setup, a plain warning that I am now the fraud
  department, and a note that this is not Shopify, whose trusted checkout,
  payment risk handling, and app ecosystem cannot be rebuilt; if volume grows,
  move to Shopify or Medusa rather than growing this.

# AGENTS.md — Build guide for Shopify

## Project scope
For a tiny shop, build catalog/cart/checkout via Stripe, order emails, and simple admin; do not expect Shopify parity.

Catalogue verdict: no. You can build a small store, but Shopify's product is hosted checkout, payments, tax/shipping integrations, app marketplace, fraud/risk tooling, and merchant operations.
Use the implementation prompt below to define the deliverable. Complete each phase's acceptance checks before extending the scope.

## Working agreement
- Inspect the repository and its existing instructions before choosing paths, dependencies or commands. Keep one coherent stack and explain changes to the proposed architecture.
- Plan a vertical slice that accepts a real input and produces the useful output described below. Persist only the state the prompt calls for; respect memory-only and upstream-managed workflows. Use fixtures only when they are clearly labelled.
- After scaffolding, document the actual install, development, check and build commands in README and keep them synchronized with the package or project manifest. Do not report commands as successful unless they ran.
- Work in small steps. At handoff, list implemented flows, checks actually performed, remaining blockers, and any credentials or provider setup the owner must supply.
- Do not publish, spend money, contact customers, delete source data or run irreversible migrations without the project owner's authorization.

## Prerequisites
- payment processor
- tax/shipping logic
- database
- hosting
- emails
- inventory/order admin

## Stack and architecture
- Node + Express + better-sqlite3 on a VPS; products in products.json (slug, name, price, images, stock count), server-rendered catalog and product pages.
- Model forms, field definitions, responses, consent flags, and exports; store source IDs and timestamps for each.
- Interface for this online store platform workflow: a local web page with input, progress, review, and export views.

## Security and data integrity
- On invalid input or interrupted processing, keep the original record, show the failed step, and permit a safe retry.
- Validate imported records and file paths; keep user data within the storage location named in the prompt.
- State the practical limit: trusted checkout.

## Agent implementation rules
- Project rule, data: Model forms, field definitions, responses, consent flags, and exports; store source IDs and timestamps for each.
- Project rule, behavior: An /admin page behind basic auth: order list and a mark-shipped button that emails the buyer with an optional tracking number.
- Project rule, recovery: On invalid input or interrupted processing, keep the original record, show the failed step, and permit a safe retry.

## Optional agent skills and references
No installable skill is listed for this guide; use the project rules and the stack documentation.

Read the linked SKILL.md and its dependencies before adding a skill. Select only the skills matching this project's runtime and task; their documentation does not supply API access, credentials or approval to perform external actions. Pin the reviewed revision where the tool supports it. Follow the chosen agent's documented project-level installation mechanism.

## Distribution ideas
These are optional planning notes. Obtain the owner's approval before publishing or contacting anyone.
- Demonstrate this online store platform operation with sample or user-owned data: An /admin page behind basic auth: order list and a mark-shipped button that emails the buyer with an optional tracking number.
- Show a concrete result or export: Hosted ecommerce platform for stores, payments, checkout, and operations.
- State the practical limit: trusted checkout.

## Engineering roadmap
1. Phase 1, architecture and data: Node + Express + better-sqlite3 on a VPS; products in products.json (slug, name, price, images, stock count), server-rendered catalog and product pages. Model forms, field definitions, responses, consent flags, and exports; store source IDs and timestamps for each.
2. Phase 2, implement: An /admin page behind basic auth: order list and a mark-shipped button that emails the buyer with an optional tracking number.
3. Phase 3, implement: For a tiny shop, build catalog/cart/checkout via Stripe, order emails, and simple admin; do not expect Shopify parity.
4. Phase 4, review and output: Hosted ecommerce platform for stores, payments, checkout, and operations.
5. Phase 5, recovery and acceptance: On invalid input or interrupted processing, keep the original record, show the failed step, and permit a safe retry. Verify this invariant with a saved fixture: An invalid input or interrupted operation must retain the source and show a recoverable state; exported records must reload with the same IDs. State the practical limit: trusted checkout.

## Paid-product capabilities outside this build
- trusted checkout
- payment risk
- app marketplace
- themes
- shipping/tax integrations
- POS
- support
- scale

## Implementation prompt
Build me a small self-hosted shop for a handful of products, the honest small
slice of Shopify. Requirements:

- Node + Express + better-sqlite3 on a VPS; products in products.json (slug,
  name, price, images, stock count), server-rendered catalog and product pages.
- Cart in a session cookie; checkout hands off entirely to Stripe Checkout
  (keys in .env). Never touch card data.
- Stripe webhook records the order, decrements stock, and emails me and the
  buyer via Resend (key in .env).
- An /admin page behind basic auth: order list and a mark-shipped button that
  emails the buyer with an optional tracking number.
- Flat shipping rates per region in a config file; sold-out products stay
  visible but cannot be bought.
- No customer accounts, no telemetry; orders stay in my SQLite file.
- Out of scope: discount engines, multi-currency, POS, and tax automation. Use
  Stripe Tax for tax; do not write tax logic.
- README: Stripe webhook setup, a plain warning that I am now the fraud
  department, and a note that this is not Shopify, whose trusted checkout,
  payment risk handling, and app ecosystem cannot be rebuilt; if volume grows,
  move to Shopify or Medusa rather than growing this.

## Completion evidence
Demonstrate the prompt's acceptance scenarios against the scoped workflow. Include setup from a clean checkout and failure recovery. Check persistence across restart and export/restore only for the state the prompt says to store; for memory-only tools, confirm that temporary content is discarded as specified. Record actual results and remaining limitations. A detailed plan alone does not establish a working replacement.