Your integration partner pushed an API change. You found out from a customer ticket.
APIWatchdog calls your third-party APIs daily and diffs the responses.
When a field disappears, a type changes, or an endpoint drifts — you know
before your users do.
$19/month per watched API.
Founding price: $79/year for up to 10 APIs, locked forever if you join before launch. Ships October 31.
First 30 days free once launched. No card charged until we ship. Full refund anytime.
That's the real diff engine from the product, running locally against a sample
payload — no mockups, no prerecorded video. Go on, break it.
How it works
1. Point us at an endpoint plus headers, or a recorded auth flow.
2. We call it on your schedule and store a normalized schema snapshot.
3. We diff structurally and email you the exact change — before your dashboard goes red.
Why you need this
Your partner's API has no obligation to tell you when it changes. Deprecation emails
get missed, version headers lie, and breaking changes ship quietly on a Friday. Your code treats
their response as a contract — a contract nobody gave you a copy of and nobody signs. Most teams
discover drift through a spiking error rate or a customer asking why their orders aren't syncing.
There's a third way: knowing first.
FAQ
Isn't this what API contracts are for?
In theory. In practice, your shipping partner's v2 endpoint changed three times last year and told nobody. We're the reality layer.
Do you store our response data?
By default only the schema fingerprint and diff metadata. Payload retention is opt-in per API.
What about authenticated APIs?
Static headers or a login flow we replay per-request, with scheduled OAuth token refresh.
What if the change is supposed to happen?
Mute a diff once, or snooze an API during your partner's announced migration window.