RetainKit Get started

Apple subscription retention

Stop losing subscribers without writing a line of code.

Apple's StoreKit retention API gives you a window to keep cancelling subscribers — if you can host the callback. RetainKit is that callback, plus the marketer-shaped UI to run it.

Get started → Connect App Store Connect Try the demo →

Two-minute look around · no signup · no Apple key

Runtime
Cloudflare Workers
Edge p50
~80ms globally
Setup
One .p8 + one URL
RetainKit rule builder showing a sentence-shaped retention rule alongside a live iOS cancel-sheet preview
Rule builder + live iOS preview

What's special

Three things make RetainKit different.

01

No code to integrate

Apple calls one URL when a user tries to cancel. We host that URL. You paste it into App Store Connect once.

  • Hosted endpoint per app: runtime.retainkit.dev/apple/retention/<appId>
  • Apple's strict <1s response budget met from Cloudflare's edge (p50 ≈ 80ms globally measured)
  • One-time setup: drop your .p8 key, paste the runtime URL into App Store Connect, you're live
  • Optional: route requests to your own backend instead if you want — we won't get in your way
02

Built for marketers, not engineers

Configure rules in three sentences. Build A/B tests with two clicks. No JIRA tickets.

  • Sentence builder: "When someone on Monthly tries to cancel, show them 50% off 3 months with message Welcome Back."
  • Drag-reorder priority, draft-state indicators, single Publish action
  • Iterations don't require an engineer or a deploy
  • Real iOS preview of the cancel sheet, live as you edit
03

Real outcome measurement, not vanity counts

We poll Apple's Subscription Status API for every offer served. Save rate, redemption rate, revenue retained — not "impressions".

  • Per-flow / per-offer / per-A/B-variant KPI tiles
  • Frequentist A/B significance (z-test + p-value), winner detection, "samples to significance" estimate
  • 30-day sparklines on every metric
  • Outcome polling silently runs every 5 min on Cloudflare Cron; data accumulates without you doing anything

How it works

Three steps from signup to live retention.

1

Connect Apple

Paste your .p8 key and key IDs on /integrations. One-time, takes a few minutes per app.

RetainKit Integrations page showing App Store Connect .p8 key upload
Integrations setup
2

Configure flows

Build sentence rules in a few clicks. Author messages, group offers, split traffic for A/B.

RetainKit Flow page with the sentence-shaped rule builder
Flow builder
3

Apple calls us

Customer hits cancel. Apple POSTs the realtime URL. We pick the rule, sign the offer, respond in ~80ms.

RetainKit Runtime page showing the hosted endpoint URL that Apple calls
Runtime endpoint

Security & infrastructure

Built on Cloudflare, designed to be inspectable.

Hosted on Cloudflare

  • Workers at the edge, D1 (SQLite at edge), KV for runtime config
  • Global p50 latency well under Apple's response-time budget
  • DDoS protection, WAF, and edge rate-limiting baked in
  • No servers to run on your side; no scaling concerns

Your Apple key, your data

  • Apple .p8 private keys are encrypted at rest with AES-256-GCM (per-org KMS-equivalent secret)
  • Never readable in plaintext outside the runtime path that signs requests to Apple
  • We don't have access to your StoreKit transactions beyond what Apple's API exposes
  • All other PII (original transaction IDs in logs) is SHA-256-hashed; raw IDs only stored encrypted for outcome polling and decrypted just-in-time

Operational hardening

  • Every config mutation is captured in an immutable audit log, viewable as a timeline per org
  • Role-based access: owner / admin / editor / viewer
  • Email verification gates production publish
  • Single sign-out option revokes every device at once
  • Each app's config is environment-aware: sandbox vs production are separate KV namespaces, never mix

Open & inspectable

  • Source for our runtime worker is public
  • No proprietary SDKs to import, no client code to ship — Apple is the only thing calling us

Use cases

What teams actually do with it.

Win-back at scale

Run "50% off 3 months" for users canceling Monthly, "1 month free" for Annual cancellers. Different offers per product without separate codepaths.

Localized retention

Different copy and offer mix per storefront, no extra deploys.

A/B everything

Test offers, copy, alternate-product suggestions. Get a p-value, not a hunch.

Existing backend? Use it.

If you'd rather Apple call your server, set your URL on the Runtime page. RetainKit becomes the config and analytics layer.

Pricing

Free during beta.

Beta

Free

$0

  • Unlimited apps during beta
  • Hosted runtime endpoint
  • Sentence builder + A/B tests
  • Outcome dashboards
  • Email support
Get started

Team

Coming soon

  • Usage-based + per-seat
  • ASSN webhook + multi-org
  • SSO included
  • For real subscription businesses
Join the waitlist