API change intelligence

Know before
it breaks.

Know what changed, why it matters, and what to do next
across every API your product depends on.

Track your first API Documentation

No credit card required.

Why Varen

Built for developers who depend on external APIs.

Generic change detectors alert you that “something changed.”
We tell you exactly what changed, why it matters, and how to fix it.

Immediate alerts

Breaking changes trigger instant alerts. Everything else goes into a daily digest.

Suggested next steps

Every breaking change comes with fix suggestions and migration guidance.

109 APIs monitored

Pre-configured catalog covering AI, payments, crypto, cloud, and more. One click to start.

Health scores

A health score for every dependency.

Every API gets a 0-100 stability score updated daily.
Spot volatile dependencies before they cause incidents.

0
Stripe
Stable
0
OpenAI
Moderate
0
AWS
Volatile
0
Twilio
Moderate
Structured diffs

See exactly what changed.

Side-by-side diffs for every API change.
No guessing, no digging through changelogs.

stripe / POST /v1/payment_intents
BREAKING
Before
01POST /v1/payment_intents
02  requestBody:
03    amount: integer
04    currency: string
05−   source: string
06    payment_method: string
07    confirm: boolean
08−   account_session: object
09−     balance_report: Component
10    customer: string
After
01POST /v1/payment_intents
02  requestBody:
03    amount: integer
04    currency: string
05    # source removed, use payment_method
06    payment_method: string
07    confirm: boolean
08    # account_session.balance_report
09    # removed in 2026-02-25.clover
10    customer: string
AI Classification

Not just change detection.
Change understanding.

Each change is tagged by type and severity so you can triage quickly.

Breaking

Endpoint removed, required param added.

Critical

Security

Auth method changed, TLS or token format updated.

Critical

Deprecation

Sunset timeline announced, feature going away.

Warning

Cosmetic

Docs rewording, example code updated.

Info

New Feature

New endpoint added, new capability available.

Info

Bug Fix

API behavior corrected, edge case fixed.

Info

Performance

Rate limits changed, response times improved.

Info
Alerts & Digests

Alerts for what needs action. Digests for everything else.

Critical changes go out immediately via email, Slack, and Telegram. Everything else is grouped into a digest you can review on your own schedule.

Email
Varen
Varen <[email protected]>
to me
Mar 15
Breaking change in Stripe API
BREAKINGMarch 15, 2026
POST /v1/payment_intents
The source parameter has been removed. Migrate to payment_method (pm_xxx).
What changed
Requests still using source will fail. Update integrations to use payment_method and confirm the request with a PaymentMethod ID.
Sent by Varen
Digest
Varen
Varen <[email protected]>
to me
Mar 16
Daily summary: 13 changes across 5 APIs
DAILY SUMMARYMar 16, 2026
Stripesource param removed from PaymentIntentsCritical
OpenAIAssistants API sunset date confirmedWarning
GitHubContent-Type header fix in SARIF endpointInfo
CloudflareError messages reworded across Pages APIInfo
AWSNew ListFoundationModels endpoint added to BedrockInfo
View 8 more changes in Varen
Sent by Varen
Slack
# api-alerts
Varen
Varen AlertsAPP2:14 PM
Breaking change in Stripe API
POST /v1/payment_intents
The source parameter has been removed
DELETE /v1/sources/{id}
Sources endpoint removed entirely
What Changed: Stripe has fully deprecated the Sources API. All integrations must migrate to PaymentMethods. Requests using source tokens will return 404.
What To Do: Replace source parameters with payment_method in your PaymentIntent creation calls.
Sent by Varen
Telegram
Varen
Varen Alerts
bot
Breaking change in Stripe API POST /v1/payment_intents The source parameter has been removed DELETE /v1/sources/{id} Sources endpoint removed entirely What Changed: Stripe has fully deprecated the Sources API. All integrations must migrate to PaymentMethods. What To Do: Replace source parameters with payment_method in your PaymentIntent creation calls. Sent by Varen
2:14 PM
Developer API

Build on top of Varen.

Integrate API monitoring into your workflow.
Automate monitors, query changes, and check health scores programmatically.

Endpoints
12endpoints
60req/min
Read the docs
Request
curl https://api.varen.dev/v1/monitors \
  -H "Authorization: Bearer vk_..."
200 OKResponse
{
  "data":  [
    {
      "id":  "mon_8f2k9x",
      "name":  "Stripe",
      "status":  "active",
      "scan_frequency":  "daily",
      "changes_detected":  3,
      "latest_change":  "breaking",
      "last_scanned":  "2026-03-23T08:00:00Z"
    }
  ],
  "meta":  { "total":  2, "page":  1 }
}
Pricing

Simple pricing. Scale when ready.

No credit card required. Upgrade when you need more APIs.

MonthlyAnnual2 months free
Hobby
$0
For developers getting started with API monitoring.
  • 3 monitored APIs
  • Daily scans
  • Daily summary email
  • Spec Compare (20/day)
  • REST API (read-only)
  • 7 days of history
  • API health scores
  • Deprecation calendar (syncs with Google, Apple, Outlook)
  • Fix suggestions and migration guidance
Track your first API
Most Popular
Pro
$15/mo
For teams shipping production apps on external APIs.
  • 15 monitored APIs
  • Hourly scans
  • Instant alerts (email, Slack, Telegram)
  • Spec Compare (unlimited)
  • REST API (full access)
  • 6 months of history
  • API health scores
  • Deprecation calendar (syncs with Google, Apple, Outlook)
  • Fix suggestions and migration guidance
  • Webhook integrations
Start Pro

Need more than 15 APIs? Contact us.

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All prices in USD. Cancel anytime — see our cancellation policy.

Catalog

Specs, docs, and changelogs. All watched.

100+ APIs preconfigured across OpenAPI specs, markdown docs, and changelogs. Every source type, one dashboard.

AI

  • AI21 Labs
  • AssemblyAI
  • Black Forest Labs
  • Cerebras
  • Claude
  • Cohere
  • Deepgram
  • DeepSeek
  • ElevenLabs
  • Fireworks AI
  • Google Gemini
  • Grok
  • Groq
  • HailuoAI
  • Hugging Face
  • Ideogram
  • Luma AI
  • Mistral
  • OpenAI
  • OpenRouter
  • Perplexity
  • Pinecone
  • Recraft
  • Replicate
  • Runway
  • Together AI
  • Voyage AI

Analytics

  • Amplitude
  • Datadog
  • Grafana
  • Mixpanel
  • PagerDuty
  • PostHog
  • Segment
  • Sentry
  • TrustMRR

Database

  • Airtable
  • Chroma
  • Convex
  • MongoDB Atlas
  • Neon
  • PlanetScale
  • Prisma
  • Qdrant
  • Snowflake
  • Supabase
  • Turso
  • Upstash
  • Weaviate

Cloud & Infra

  • AWS
  • Azure
  • Cloudflare
  • Cloudinary
  • DigitalOcean
  • Firebase
  • Fly.io
  • Google Cloud
  • Mapbox
  • Render

Payments

  • LemonSqueezy
  • Paddle
  • PayPal
  • Plaid
  • Shopify
  • Square
  • Stripe
  • Wise

Fintech

  • Finlight
  • Massive

Crypto

  • Alchemy
  • Binance
  • Coinbase
  • CoinGecko
  • Etherscan
  • MetaMask

Business

  • Algolia
  • Auth0
  • Clerk
  • Contentful
  • HubSpot
  • Meilisearch
  • Okta
  • Salesforce
  • Sanity
  • Typesense
  • WorkOS
  • Zoho CRM

Communication

  • Calendly
  • Discord
  • Liveblocks
  • Notion
  • Postmark
  • Pusher
  • Resend
  • SendGrid
  • Slack
  • Spotify
  • Twilio
  • Twitch
  • Zoom

DevTools

  • Cursor
  • Figma
  • GitHub
  • GitLab
  • Jira
  • LaunchDarkly
  • Linear
  • Netlify
  • Vercel

Don't see your API? Let us know. We're adding new APIs every week.