SpecWatch

Dependabot, but for the APIs you call

Know before
it breaks.

The APIs you build on change without asking you. SpecWatch watches their OpenAPI specs continuously and tells you — in plain English — the moment a change will break your code. Not a 500 at 2 a.m. A heads-up in minutes.

Stripe · GitHub · OpenAI · Twilio · Slack · Supabase · Cloudflare · Square · Plaid — watched from day one. No credit card.

stripe/openapi-spec3.yamlwatching · poll #418
1openapi: 3.1.0
2paths:
3 /v1/payment_intents:
4 post:
5 summary: Create a payment intent
6 parameters:
7 - name: amount
8 required: [amount]- removed
9 required: [amount, customer]+ added
10 - name: customer
11

severity

BREAKING

breakingstripe · 4 min ago

Creating a payment intent now requires a customer ID. Calls without one will start failing.

The old way

You find out an API changed when your users find out.

The unsubscribe

The vendor has a changelog. It has an RSS feed. You meant to read it. You don't.

The 2 a.m. alert

Your error tracker tells you first — after the 500s reach your users, in production.

The Reddit thread

Three days later you find the forum post explaining what changed and why it broke you.

YC reports that 30% of AWS downtime traced back to unnoticed changes in external APIs and packages. The spec was public the whole time. Nobody was reading it.

The shift

A raw diff tells you what moved.
SpecWatch tells you what it means.

- paths./charges.post.parameters[4]

- required: [amount]

+ required: [amount, customer]

- components.Charge.currency: string

+ components.Charge.currency: enum

// 400 lines like this, per release, per API

breakingstripe · 4 min ago

Creating a payment intent now requires a customer ID, and currency now only accepts a fixed set of values. Update your checkout calls before the next release rolls out.

The engine

Four steps, fully automated, zero vendor setup.

01

Watch

We poll the public OpenAPI spec of every API you watch, every 10 minutes, with conditional requests. No vendor cooperation needed.

02

Diff

Each spec is normalized — refs resolved, volatile noise stripped — then deep-diffed against the last known-good snapshot, semantically.

03

Classify

Deterministic rules assign severity: a removed endpoint or newly-required parameter is breaking. AI translates each diff into plain English.

04

Alert

Within minutes, you get an email and Slack message that says what changed, where, and what will break — not a wall of JSON.

Missing an API? Request it — if it publishes an OpenAPI spec, it can be watched. No vendor cooperation required.

The proof

Watched from day one. Every catch is public.

StripeGitHubOpenAITwilioSlackSupabaseCloudflareSquarePlaid

Every change the engine catches lands on the public feed — the same detections paying users get alerted on. Watch it fill up in real time; that is the product working.

Pricing

Less than one hour of downtime.

Start free, upgrade when you want alerts in minutes instead of a weekly digest. Cancel in one click.

Free$0 forever
  • Watch 3 APIs
  • Weekly digest email
  • Public change feed
Start free
Pro$19 /month
  • Unlimited APIs
  • Within-minutes email alerts
  • Slack alerts
  • Breaking-change-only filter
Get alerts in minutes
Team$49 /month
  • Everything in Pro
  • Shared watchlist
  • Per-vendor Slack routing
Watch as a team

Free forever for 3 APIs. Paid plans billed via Polar, cancel anytime.