Stripe vs ReplaySafe
Stripe's idempotency keys prevent duplicate Stripe API calls. ReplaySafe prevents duplicate real-world consequences across your entire system - emails, webhooks, database writes, GitHub issues, and any custom API.
Side by Side
The Core Difference
Stripe Idempotency
Prevents duplicate API callsto Stripe. If you send the same idempotency key twice within 24 hours, Stripe returns the cached response. But it doesn't know about your emails, webhooks, database writes, or other side effects.
ReplaySafe
Prevents duplicate real-world consequences across your entire system. Fingerprints every operation and tracks it through a full lifecycle. When something times out, it asks the provider what actually happened before retrying.
When to Use Which
Use Stripe Idempotency When
You only care about duplicate Stripe calls, you're okay with 24-hour key expiry, and you don't need cross-system coordination or verification.
Use ReplaySafe When
You have multiple side effects (payments + emails + DB writes), you need provider verification when outcomes are unknown, you want crash recovery with guard.resume(), or you're running multiple agents that need to coordinate.
You Can Use Both
ReplaySafe doesn't replace Stripe's idempotency keys — it layers on top. You can still pass idempotency keys to Stripe while ReplaySafe tracks the full lifecycle and coordinates across your entire system.
// ReplaySafe + Stripe idempotency — belt and suspenders
const result = await guard.effect({
type: 'STRIPE_OPERATION',
target: 'stripe-charge',
input: { orderId, amount: 2999 },
provider: 'stripe',
execute: () => stripe.charges.create(
{ amount: 2999, currency: 'usd' },
{ idempotencyKey: `order_${orderId}` } // Stripe's built-in dedup
),
receipt: (r) => ({ chargeId: r.id }),
})Next Steps
Ready to add execution memory to your agents? Start with the ReplayGuard SDK.