SamCart

Build me a focused checkout + courses workflow for the personal core of SamCart. Requirements:

- Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL + Stripe. Model products, buyers, purchases, entitlements, and delivery receipts; keep stable source IDs and timestamps.
- Paid product context: Conversion-focused checkout, subscriptions, upsells, courses, and affiliates. Build only this DIY scope: Build a narrow checkout + courses storefront or member area for one creator, using Stripe Checkout and explicit digital-delivery rules.
- For checkout + courses, define products or membership access rules and record prices in integer minor currency units.
- Create a checkout session through the user’s payment provider and verify the signed completion webhook.
- Grant digital access exactly once and show purchase, refund, and delivery history.
- Use a local web page with input, progress, review, and export views. Required input or access: Stripe account and API keys in .env. Keep credentials in .env.
- Acceptance: with one labelled sample, show the input, saved intermediate state, and exported result; verify this invariant: A repeated payment webhook cannot deliver twice; a refund must revoke the relevant access without deleting the audit trail.
- Out of scope: fulfilment, email, and affiliate ecosystems; marketplace discovery and buyer trust. Keep this a personal, inspectable workflow.
- Include a README with setup, a sample input, required keys or permissions, data location, and the supported scope.

# AGENTS.md — Build guide for SamCart

## Project scope
Build a narrow checkout + courses storefront or member area for one creator, using Stripe Checkout and explicit digital-delivery rules.

Catalogue verdict: no. Do not mistake the interface for the product. SamCart's durable value is payments, network, compliance, which a solo one-shot build cannot reproduce responsibly. The prompt therefore builds only the closest honest personal consolation tool.
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
- Node.js 22
- PostgreSQL
- Stripe account and API keys in .env
- Explicit README warning that this is a consolation build, not a production replacement

## Stack and architecture
- Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL + Stripe.
- Model products, buyers, purchases, entitlements, and delivery receipts; keep stable source IDs and timestamps.
- Interface for this checkout + courses workflow: a local web page with input, progress, review, and export views.

## Security and data integrity
- A repeated payment webhook cannot deliver twice; a refund must revoke the relevant access without deleting the audit trail.
- Keep API keys and OAuth secrets in .env; redact them from logs, generated files, and error responses.
- State the practical limit: fulfilment, email, and affiliate ecosystems.

## Agent implementation rules
- Project rule, data: Model products, buyers, purchases, entitlements, and delivery receipts; keep stable source IDs and timestamps.
- Project rule, behavior: For checkout + courses, define products or membership access rules and record prices in integer minor currency units.
- Project rule, recovery: A repeated payment webhook cannot deliver twice; a refund must revoke the relevant access without deleting the audit trail.

## 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 checkout + courses operation with sample or user-owned data: For checkout + courses, define products or membership access rules and record prices in integer minor currency units.
- Show a concrete result or export: Grant digital access exactly once and show purchase, refund, and delivery history.
- State the practical limit: fulfilment, email, and affiliate ecosystems.

## Engineering roadmap
1. Phase 1, architecture and data: Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL + Stripe. Model products, buyers, purchases, entitlements, and delivery receipts; keep stable source IDs and timestamps.
2. Phase 2, implement: For checkout + courses, define products or membership access rules and record prices in integer minor currency units.
3. Phase 3, implement: Create a checkout session through the user’s payment provider and verify the signed completion webhook.
4. Phase 4, review and output: Grant digital access exactly once and show purchase, refund, and delivery history.
5. Phase 5, recovery and acceptance: Verify this invariant with a saved fixture: A repeated payment webhook cannot deliver twice; a refund must revoke the relevant access without deleting the audit trail. State the practical limit: fulfilment, email, and affiliate ecosystems.

## Paid-product capabilities outside this build
- fulfilment, email, and affiliate ecosystems
- marketplace discovery and buyer trust
- tax, disputes, payouts, and fraud operations
- native apps and community moderation

## Implementation prompt
Build me a focused checkout + courses workflow for the personal core of SamCart. Requirements:

- Use exactly this stack: Next.js 15 + TypeScript + PostgreSQL + Stripe. Model products, buyers, purchases, entitlements, and delivery receipts; keep stable source IDs and timestamps.
- Paid product context: Conversion-focused checkout, subscriptions, upsells, courses, and affiliates. Build only this DIY scope: Build a narrow checkout + courses storefront or member area for one creator, using Stripe Checkout and explicit digital-delivery rules.
- For checkout + courses, define products or membership access rules and record prices in integer minor currency units.
- Create a checkout session through the user’s payment provider and verify the signed completion webhook.
- Grant digital access exactly once and show purchase, refund, and delivery history.
- Use a local web page with input, progress, review, and export views. Required input or access: Stripe account and API keys in .env. Keep credentials in .env.
- Acceptance: with one labelled sample, show the input, saved intermediate state, and exported result; verify this invariant: A repeated payment webhook cannot deliver twice; a refund must revoke the relevant access without deleting the audit trail.
- Out of scope: fulfilment, email, and affiliate ecosystems; marketplace discovery and buyer trust. Keep this a personal, inspectable workflow.
- Include a README with setup, a sample input, required keys or permissions, data location, and the supported scope.

## 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.