> ## Documentation Index > Fetch the complete documentation index at: https://docs.fluid.app/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > For new direct REST integrations, use the v2026-04 surfaces. The @fluid-app FairShare SDK continues to use its own published public-v2025-06 contract. > Authenticate with the header Authorization: Bearer ; public storefront read endpoints require no auth. > Lists use cursor pagination via the page[cursor] and page[limit] query params; follow meta.pagination.next_cursor until it is null. > Never use /api/company/v1 or /api/v1 paths, page/per_page params, or offset pagination — they are legacy. > The OpenAPI specs under api-reference/ are the authoritative contracts; prefer them over prose when in doubt. api-reference/storefront-v2026-04.yaml covers the v2026-04 storefront surface (/api/v202604/... paths); api-reference/auth-v0.yaml covers the unversioned auth surface (/api/... paths — authentication, MFA, social auth, and token exchange); api-reference/checkout-v2026-04.yaml covers the v2026-04 checkout surface (/api/checkout/v2026-04/... paths — carts, cart auth, discounts, items, subscriptions, orders, enrollments, and store config); api-reference/public-v2025-06.yaml covers the Public SDK surface used by the @fluid-app FairShare SDK, including its parallel cart lifecycle, browser integrations, versioned payment callbacks, unversioned public utilities, and the cart price-override operation; api-reference/payment-v2026-04.yaml covers the v2026-04 payment gateway admin surface (/api/payment/v2026-04/... paths, bearer-authenticated — gateway CRUD, gateway purchase/authorize/$0-verify, transaction list/show and capture/void/credit, and merchant payment configuration); api-reference/payments-v2026-04.yaml covers the v2026-04 cart payment surface (/api/payments/v2026-04/carts/{cart_token}/... paths, authenticated by the cart token in the path with no bearer — payment-method selection, VGS card tokenization, 3D Secure verification, and PayPal/Braintree/Klarna/Apple Pay flows); api-reference/commerce-v2026-04.yaml covers the v2026-04 commerce order-editing surface (/api/v202604/orders/{order_id}/edits paths, bearer-authenticated — post-checkout order edits that atomically insert items and add adjustments/discounts, with an optional dry-run preview); api-reference/webhooks-v0.yaml covers the unversioned webhooks surface (/api/... paths — webhook registration, delivery payloads, callback registrations, company events, and webhook/callback schemas). > Successful responses wrap the resource payload alongside a top-level integer status and a meta object. # Preview a failed-cycle waiver > Returns the authoritative future billing and shipping timestamps that would be restored if the exhausted failed cycle were waived. An ineligible subscription returns 200 with eligible false and null dates. ## OpenAPI ````yaml /api-reference/checkout-v2026-04.yaml get /api/checkout/v2026-04/subscriptions/{token}/failed-cycle-waiver openapi: 3.1.0 info: title: Fluid Checkout API description: >- **Fluid Checkout API — for building a checkout directly against REST.** Use this surface if you are integrating server-to-server or building your own checkout UI. It covers the full order lifecycle (cart → address → shipping → discount → complete → order) plus the logged-in customer's account: saved addresses, saved payment methods, order history, loyalty points, and subscription management (pause, resume, skip, cancel, retry). **The cart token in the URL scopes cart access** — creating a cart, adding items, applying a discount, and completing a cart need no bearer token. Among the cart operations, a Bearer token is required only for `carts/{cart_token}/sync`, `carts/{cart_token}/volume_rep`, and `carts/{cart_token}/discount/manual`. Off the cart, a token is required for everything under `customers/me` and `subscriptions`, and for the store and directory lookups (`store/config`, `store/languages`, `reps`, `users`) and `subscription_bundles`. `store/countries` accepts a token but does not require one — it returns the same list either way. **If you are using the `@fluid-app` FairShare SDK in a theme or storefront, you are not calling this surface** — the SDK calls the Fluid Public SDK API (`public-v2025-06`). Do not mix the two against one cart: they share the same cart records and services, but their request shapes differ. See [Choosing a cart surface](https://docs.fluid.app/api/choosing-a-cart-surface) for the operation map and boundary. version: v2026-04 contact: email: support@fluid.app license: name: Proprietary identifier: LicenseRef-Proprietary servers: - url: https://api.fluid.app security: [] tags: - name: carts description: >- Create, read, and mutate checkout carts (email, address, country, language, shipping, recalculation, completion). - name: cart-auth description: >- Cart-scoped customer authentication — magic-link challenge, verification, identity, and logout. - name: cart-discount description: >- Apply, list, and remove cart discount codes, including admin manual discounts. - name: cart-items description: Add, update, and remove line items on a cart. - name: cart-points description: Apply and remove loyalty points on a cart. - name: customers description: The authenticated customer's profile and company memberships. - name: customer-addresses description: The authenticated customer's saved shipping/billing addresses. - name: customer-orders description: The authenticated customer's order history. - name: customer-payment-methods description: The authenticated customer's saved payment methods and tokenization. - name: customer-points description: The authenticated customer's loyalty point balances. - name: directory description: Company rep and user directory lookups. - name: enrollments description: >- Public enrollment forms — retrieve a form and submit, update, or upload field answers. - name: orders description: Public order lookup by token. - name: products description: Public product queries for the storefront checkout. - name: store description: >- Store-level checkout configuration — countries, languages, address fields, agreements, drop zones, and Apple Pay domain verification. - name: subscriptions description: >- Manage subscriptions — pause, resume, skip, cancel, reactivate, retry, and failed-cycle waivers. - name: subscription-bundles description: List and create subscription bundles. paths: /api/checkout/v2026-04/subscriptions/{token}/failed-cycle-waiver: get: tags: - subscriptions summary: Preview a failed-cycle waiver description: >- Returns the authoritative future billing and shipping timestamps that would be restored if the exhausted failed cycle were waived. An ineligible subscription returns 200 with eligible false and null dates. operationId: checkout_v2026_04_failed_cycle_waiver_preview parameters: - name: token in: path required: true description: Subscription token schema: type: string responses: '200': description: Authoritative waiver eligibility and restored schedule content: application/json: schema: $ref: '#/components/schemas/FailedCycleWaiverPreviewResponse' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/UnauthorizedResponse' '404': description: Subscription not found or not owned by the authenticated customer content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - bearer_auth: [] components: schemas: FailedCycleWaiverPreviewResponse: type: object additionalProperties: false required: - failed_cycle_waiver - meta properties: failed_cycle_waiver: $ref: '#/components/schemas/FailedCycleWaiverPreview' meta: $ref: '#/components/schemas/CheckoutMeta' UnauthorizedResponse: type: object properties: message: type: string required: - message ErrorResponse: type: object additionalProperties: false required: - error_message - errors - meta properties: error_message: type: string errors: $ref: '#/components/schemas/ErrorBag' meta: $ref: '#/components/schemas/CheckoutMeta' FailedCycleWaiverPreview: description: Authoritative schedule preview for abandoning an exhausted failed cycle. type: object additionalProperties: false required: - eligible - next_bill_date - next_ship_date properties: eligible: type: boolean description: Whether the subscription can waive its exhausted failed cycle now. next_bill_date: type: - string - 'null' format: date-time description: >- Restored billing timestamp, or null when the subscription is ineligible. next_ship_date: type: - string - 'null' format: date-time description: >- Restored shipping timestamp, or null when the subscription is ineligible. CheckoutMeta: type: object additionalProperties: false required: - request_id - timestamp properties: request_id: type: - string - 'null' timestamp: type: string format: date-time ErrorBag: description: >- Validation errors keyed by field, a list of errors, a single error message, or null when no structured error details are available. anyOf: - type: string - type: array items: $ref: '#/components/schemas/ErrorValue' - type: object additionalProperties: $ref: '#/components/schemas/ErrorValue' - type: 'null' ErrorValue: description: A validation or API error value. anyOf: - type: string - type: array items: type: string - type: object additionalProperties: $ref: '#/components/schemas/JsonValue' JsonValue: description: >- Any valid JSON value for provider, integration, theme, metadata, or other dynamic payloads whose keys are not fixed by the API contract. anyOf: - type: string - type: number - type: boolean - type: 'null' - type: array items: $ref: '#/components/schemas/JsonValue' - type: object additionalProperties: $ref: '#/components/schemas/JsonValue' securitySchemes: bearer_auth: type: http scheme: bearer description: Bearer token authentication ````