Larkspur APIAPI
Payments, as an API.
Bugs
View AllKeys Look IdenticalBoth are 32 characters starting lk. I've pasted the wrong one into production more than once and I won't be the last.Under Review
Webhook Retry StormA 3-second response gets six retries inside a minute, which turns a slow endpoint into a dead one.In Progress
Features
View AllIdempotent RefundsPayments take an idempotency key. Refunds do not, so a timeout on our side means we genuinely cannot tell whether the customer has been refunded once or twice without going to…Under Review
A Test ClockWe bill monthly and cannot test a renewal without waiting a month or faking our own dates, which means the retry path has never been tested end to end. That is the path that…Planned
Roadmap
View AllWebhook Retry StormA 3-second response gets six retries inside a minute, which turns a slow endpoint into a dead one.In Progress
A Test ClockWe bill monthly and cannot test a renewal without waiting a month or faking our own dates, which means the retry path has never been tested end to end. That is the path that…Planned
Changelog
View AllReplay AnythingEvery delivery attempt is kept for thirty days and can be replayed, singly or by window Replays keep the original event id Clearer failure reasons on declined payments, mapped to the issuer's own wordingv4.2.0Jul 6
Steadier Under LoadRoughly 30% faster authorisation at peak Idempotency keys held for 48 hours rather than 24 Better handling of issuer timeouts, with fewer false declinesv4.1.2Jun 14
FAQ
View AllHow do I get help quickly?Post here and you will get a first reply within the hour, at any time of day. Anything…Do we need to be PCI compliant?Only at the lightest level, provided card details go straight from your customer's browser…Are webhooks delivered exactly once?No, and no payments API should tell you otherwise. Delivery is at-least-once, so key on the…
Testimonials
View All“Reported something on a Sunday evening and had a reply before I had closed the laptop. It was fixed that week.”
An integration leadJul 2026🇬🇧