About
Infrastructure that gets out of your way.
Calder started from a simple frustration: sending an email from an application should be one API call, but doing it well means providers, DNS, queues, retries, webhooks, suppression, and billing — fragmented across six vendors. We're assembling it into one coherent system.
How we work
Five principles, actually enforced.
Boring where it counts
Infrastructure should be predictable. We save the excitement for the design and spend it nowhere else.
Debuggability is a feature
Every operation leaves a trail. If you can't inspect it, we didn't finish building it.
Transactional first, only
We will not become a newsletter platform. Focus is a deliverability strategy.
Honest pricing
Naira and dollars, hard limits, metered from records. The invoice matches the dashboard or it's a bug.
Design is infrastructure too
Developer tools deserve the same craft as consumer products. This page is the argument.
Get started
Go get your first delivery.
Not your first signup form, not your first dashboard tour — your first email, landing in an inbox, with the webhook to prove it. Test keys are free and can’t hurt anything. The only thing standing between you and that little delivered tag is one POST request.