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acme/paymentsSample repository · simulated runStage · 1/5

01 · API change

Stripe changed how billing cycle anchors are sent.

Three calls now take an object where they took a string. Code that still sends a string, such as ’now’, no longer matches the API.

Release: Endive · Sept 2026
Breaking: Yes · 1 of 28
Recorded as: field_type_changed
Read from: Stripe’s changelog

Stripe changelogEndiveBreaking

Unifies the billing cycle anchor format across Subscriptions and Invoices

subscriptions.update()'now' | 'unchanged'{ type }
subscriptions.resume()'now' | 'unchanged'{ type }
invoices.createPreview()subscription_details.billing_cycle_anchor'now' | 'unchanged' | timestamp{ type, timestamp }

What changes in a request

−billing_cycle_anchor: 'now'+billing_cycle_anchor: { type: 'now' }

Simulated run on a sample repository. The Stripe change is real; the code and results are illustrative.Stripe’s changelog (opens in a new tab)

Breaking changes in Stripe’s September 2026 releaseCheck here: Stripe’s changelog for the Endive release, opens in a new tab: 28
Of developer time goes to maintenanceCheck here: Stripe’s survey, The Developer Coefficient, a PDF, opens in a new tab: 42%
Merges without your review: 0
To start: Free

Stripe changelogSample

Breaking

Billing cycle anchors now take an object

Endive · update · resume · createPreview

ImpactSample

change-plan.tsLine 12
preview.tsLine 13
resume.tsLine 6
signup.tsClear

MigrationSample

− billing_cycle_anchor: anchor,+ billing_cycle_anchor: {+   type: 'timestamp',+   timestamp: anchor,+ },

preview.ts · 4 files · +9 −4

ValidationSample

Typecheck
Lint
Tests 212/212
Build

Pull requestSample

Verified

Update Stripe integration: billing_cycle_anchor type changed

Review required · Mantle never merges

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stripe.checkout.sessions.create()

Checkout Sessions

stripe.paymentIntents.confirm()

Payment Intents

stripe.subscriptions.update()

Subscriptions

stripe.webhooks.constructEvent()

Webhooks

stripe.customers.create()

Customers

stripe.invoices.finalizeInvoice()

Invoices

stripe.refunds.create()

Refunds

stripe.prices.list()

Prices

stripe.setupIntents.create()

Setup Intents

stripe.billingPortal.sessions.create()

Customer Portal

stripe.paymentMethods.attach()

Payment Methods

stripe.products.create()

Products

stripe.subscriptionSchedules.create()

Subscription Schedules

stripe.accounts.create()

Connect Accounts

Every Stripe call, watched

Mantle is reading the Stripe changelog
Mantle is recording every change as data
Mantle is finding the code each change touches
Mantle is tracing calls through your repository
Mantle is opening a disposable workspace
Mantle is writing the migration
Mantle is running your type checks
Mantle is running your linter
Mantle is running your tests
Mantle is building your project
Mantle is opening a verified pull request
Mantle is waiting for your review
Mantle is never merging on its own
Mantle is watching for the next change

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