feat: the billing release, against Kaiten 26.10.8

CHANGELOG.md

@@ -5,15 +5,62 @@ All notable changes to this project are documented here. The format follows
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html): only a major version changes the
 public API, a minor version adds to it, and a patch version fixes it.
 
-## [Unreleased]
+## [1.1.0] - 2026-11-01
+
+Generated and tested against the contract of Kaiten 26.10.8,
+[`kaitencloud/kaiten@f685ceb8`](https://github.com/kaitencloud/kaiten/commit/f685ceb86bfeb5f6110663662fb955336ce1a1a4):
+use it with Kaiten 26.10.8 or later. Nothing 1.0.0 published was removed or renamed: methods
+only gained optional arguments.
 
 ### Added
 
+- `client.billing`, a namespace per billing resource: the organization's settings, capabilities,
+  health, provider sync and period close; `subscriptions` -- subscribe, change the provider and
+  terms, cancel, reactivate, schedule and drop a plan change, the upcoming invoice, an instance's
+  invoices; `invoices` -- list, export, void, recompose, mark paid, write off, release a hold,
+  retry a push, sync, and a line's usage reports; the accounting `handoff`, claimed and
+  acknowledged; `license_prices` and the invoice preview; `addons`, with their families, grants,
+  prices and the license families they fit; `instance_addons`; `vouchers`, their redemptions and
+  lookup, and `instance_vouchers`; `customers` -- a customer's billing, payment method and
+  provider portal; `publishable_keys`, `customer_sessions` and `checkout_sessions`.
+- `client.billing.public` and `client.billing.session`: what a publishable key (`pk_...`), an
+  anonymous checkout's token (`ksc_...`) and a customer session (`kst_...`) reach. A route under
+  `/public` takes one of them and refuses any other; the SDK refuses the mix-up before sending,
+  and sends a publishable key in `X-Kaiten-Publishable-Key`, never as a bearer token.
+- `instances.report_usage_detailed()`: a usage report under an idempotency key,
+  `transaction_id`, which Kaiten applies at most once. It returns a `UsageReportResult`: the
+  usage, whether the report was a replay, and whether its metadata was too large to store. A key
+  spent on another report raises `TransactionIdReusedError`.
+- The usage history: `instances.list_usage_reports()`, `instances.export_usage_reports()` and
+  `instances.export_organization_usage_reports()`.
+- Entitlement exceptions: `instances.list_entitlement_exceptions()`,
+  `instances.create_entitlement_exception()` and `instances.revoke_entitlement_exception()`.
+- `license_families.update()`: whether a family is public, its fallback family, and how its
+  trials end.
+- A license version's commercial terms on `licenses.create()` and `licenses.update()`:
+  `pricing_type`, `trial_period_days`, `requires_payment_method` and `self_serve_cta_url`. A
+  customer's `billing_email` on `customers.create()` and `customers.update()`.
+  `metadata_fields.list(include_archived=True)`.
+- `platform.billing.close_periods()`, the Platform API's eleventh operation.
+- Models for every new response, and for the 62 webhook events published since 1.0.0: all 117
+  are typed. An event carries the delivery's trace `headers`, and its `data` who wrote the change
+  (`via`, `checkout_session_id`, `customer_session_id`); that `data` is still an instance of the
+  class 1.0.0 typed it with.
 - `feature_flags.targeting_context()`, `feature_flags.lint_rule()` and `feature_flags.test_rule()`:
   the facts a targeting rule can read, the check the API runs before accepting one, and a dry run
   of a rule against a customer or an instance.
 - `feature_flags.update(..., slug=...)` renames a flag.
 
+### Changed
+
+- The models require what Kaiten 26.10.8 always sends and older deployments do not:
+  `EntitlementUsage.source`, `AuditTrail.actor`, `ConnectorSettings.configured`, the trial and
+  catalog settings of `LicenseFamilyView`, and the period rollover event's `reason`. From an older
+  Kaiten, those reads raise `APIResponseValidationError`, and that event `WebhookPayloadError`.
+- `ResetAnchor` gains `BILLING_PERIOD`, and `Scope` the `read:` and `write:` scopes of `addons`,
+  `billing`, `customer_sessions`, `profile`, `publishable_keys`, `users`, `voucher_redemptions` and
+  `vouchers`.
+
 ### Fixed
 
 - `feature_flags.update` sends the flag's slug. Without it, Kaiten blanked the slug and the flag
@@ -66,4 +113,5 @@ The first release of the Kaiten Python SDK, generated and tested against the con
 - Flag evaluation. Kaiten implements OFREP, so flags are evaluated with an OpenFeature SDK and
   its generic OFREP provider (`openfeature-provider-ofrep`); the README shows how.
 
+[1.1.0]: https://github.com/kaitencloud/sdk-python/releases/tag/v1.1.0
 [1.0.0]: https://github.com/kaitencloud/sdk-python/releases/tag/v1.0.0