Stripe Design

Create a design document for Stripe integration.

Objective

Produce a clear, implementable design that follows our business model preferences and current Stripe best practices.

Process

1. Understand Requirements

What does this app need? Usually one of:

• Subscription billing (most common)

• One-time payments

• Both

Reference business-model-preferences for constraints: single tier, trial with completion on upgrade, no freemium.

2. Research Current Patterns

Stripe's API evolves. Before designing:

• Use Gemini to check current Stripe Checkout best practices

• Verify webhook event recommendations

• Check if there are new patterns for your use case

Don't assume last year's patterns are still optimal.

3. Design the Integration

Produce a design document covering:

Checkout Flow

• Embedded or redirect?

• What mode? (subscription, payment, setup)

• Customer creation strategy

• Success/cancel URLs

• Trial strategy: Credit card upfront (preferred) with trial_period_days

Webhook Events

• Which events to handle?

• Idempotency strategy

• Error handling approach

Subscription State

• What fields to store locally?

• Access control logic

• Trial handling

Price Structure

• Monthly price (and annual if applicable)

• Trial duration

4. Get Validation

Run the design through Thinktank for multi-perspective review. Billing is critical — get expert opinions before implementation.

Output

A design document that stripe-scaffold can implement. Include:

• Architecture decisions with rationale

• Specific Stripe API features to use

• Data model for subscription state

• Webhook events to subscribe to

• Access control logic

Adaptation

Design for the detected stack (usually Next.js + Convex + Clerk). If stack differs, adapt the design to that stack's patterns while maintaining the same Stripe concepts.