a2a-Market Stripe Payment

Create the Stripe payment integration skeleton for order settlement.

Current status: registration scaffold with stable payment contracts and webhook map.

Scope

• Create payment intent from negotiated order terms.
• Capture or cancel payments based on order transitions.
• Reconcile webhook events with internal order state.

Suggested Project Layout

• app/integrations/stripe/stripe_client.py
• app/application/services/payment_service.py
• app/interfaces/api/payment_routes.py
• app/infrastructure/tasks/stripe_webhook_worker.py

Minimum Contracts (MVP P0)

1. create_payment_intent(order_id, amount, currency) returns provider intent id + client secret.
2. capture_payment(provider_intent_id) captures authorized funds.
3. cancel_payment(provider_intent_id) voids uncaptured authorization.
4. handle_webhook(event) verifies signature and upserts payment status.

Event Mapping

• Emit ORDER_CREATED when payment intent is created.
• Emit PAYMENT_SUCCEEDED when capture confirms.
• Emit payment-failed incident event when authorization/capture fails.

Guardrails

• Verify webhook signature before parsing payload.
• Enforce idempotency key for create/capture endpoints.
• Keep provider status mapping table explicit and versioned.

Implementation Backlog

• Add partial refund and dispute webhook handling.
• Add multi-currency routing and fee optimization.

Runtime Implementation

• Status: implemented in local runtime package.
• Primary code paths:
• runtime/src/integrations/stripe/stripe-payment-service.js
• Validation: covered by runtime/tests and npm test in runtime/.