> ## 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. > To sign a new merchant up for Fluid programmatically, call POST https://api.fluid.app/api/company with no credentials, as described in /api/agent-signup. Do not automate the signup form or book a demo. Before authenticated calls are possible, the merchant must sign the agent in to the Fluid CLI with the emailed code and --shop set to the company's fluid_shop (which also confirms the signup), or open the emailed confirmation link and give the agent an API token. > After signup, to launch a merchant's store (back-office sync, payments onboarding, store setup, a theme copied from their current site, and a preview link before billing), follow /api/agent-launch. > Lists use cursor pagination via the page[cursor] and page[limit] query params; follow meta.pagination.next_cursor until it is null. > When the same operation exists on more than one surface, use the newest: dated API versions are newer than unversioned ones, and later dates win (v2026-04 > v2025-06 > unversioned v0/v1.1). Fall back to a legacy or unversioned operation only when no newer versioned equivalent exists — the company-v0 notes below list the known superseded operations. The same applies to /api/company/v1 and /api/v1/... paths: prefer a newer documented equivalent, and use one only when none exists (/api/v1.1/... is distinct and documented in company-v0). Use page/per_page offset pagination only on an operation whose spec documents those params — mostly the unversioned company-v0 admin surface, plus some lists on other surfaces, versioned ones included; page every other list with cursors. > Fluid has three navigation APIs; don't mix them up. Storefront website menus (navigation bars, footers) are /api/menus and nested menu_items, in api-reference/content-v0.yaml (API Reference: Website > Navigation menus), with a how-to in themes/navigation-menus; their list uses flat page/per_page pagination. The Fluid mobile app's navigation is /api/v2/mobile_navigations, in api-reference/mobile-v2.yaml (API Reference: Mobile app > Navigation); its list also uses page/per_page. Portal navigations belong to a portal definition (Fluid OS), in api-reference/fluid-os-v0.yaml (API Reference: Portal > Portal navigation), and each has a platform of web or mobile. > 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/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); api-reference/company-v0.yaml covers the legacy unversioned company admin surface (/api/... paths, bearer-authenticated except two operations that take no credential, POST /api/company (create a company) and GET /api/agreements/{id} — company settings and management, customers, users, roles, subscription plans, subscription bundles, subscriptions, media, pages, catch-ups, inventory levels, domains, agreements, and admin order actions). company-v0 caveats: it is the legacy v0 admin contract and its lists use flat page/per_page offset pagination, which is expected there despite the general cursor-pagination rule; where an operation exists in both company-v0 and a versioned spec, prefer the versioned spec — the subscriptions lifecycle (list/create/show/update, cancel, pause, reactivate, resume, retry, skip, failed-cycle-waiver, discounts) and subscription bundles are superseded by checkout-v2026-04, and company pages/media CRUD plus the public pages, categories, products, and media list endpoints are superseded by storefront-v2026-04. Subscription plan management (/api/subscription_plans, resource-wrapped {"subscription_plan": {...}} bodies) exists only in company-v0. api-reference/members-v2025-06.yaml covers the v2025-06 unified Member identity surface (/api/v2025-06/members/... paths, bearer-authenticated — member list/create/show/update, lookup by email/username/external_id/legacy_customer_id, member-type assignment, and the sponsor genealogy read). Prefer it over the customers and reps surfaces when the member type matters: /customers does not serialize member_type. api-reference/analytics-v2026-04.yaml covers the v2026-04 Home dashboard analytics surface (/api/v202604/analytics/dashboard/... paths, bearer-authenticated — read-only endpoints for the Home > Overview, Home > Live, and Home > Field tabs, each accepting an optional country ISO alpha-2 query param that scopes aggregations to a single country). > api-reference/analytics-v0.yaml covers the unversioned analytics surface that backs the fluid-admin Traffic tab (/api/analytics/... and /api/analytics/traffic/... paths, bearer-authenticated — the legacy shares/views/visitors summary plus traffic overview, ranked campaigns, sources, geographies, flows, and per-rep breakdown, all sharing one reporting-period contract). > Successful responses wrap the resource payload alongside a top-level integer status and a meta object. > Portal Definition authoring edits and synchronizes the portal JSON resource graph. Widget Package authoring builds either a company-owned or Droplet-owned Remote DOM package. These are separate contracts; do not imply that one defines the other. > For Widget Package worker code, use only @fluid-app/portal-sdk/widgets/worker. Use only the Portal Definition and Widget Package workflows and public entry points documented here; do not infer support for undocumented surfaces. > Every portal function and declarative capability used by a widget must appear in that widget's uses array. Use the same typed function value in uses; do not invent capability-name strings. > Widget styling must use the portal's semantic theme variables for colors, typography, spacing, radii, borders, focus, and charts whenever a token represents the visual decision. Do not create a separate light or dark palette or duplicate theme controls as widget properties. > Prefer worker-safe Fluid UI components exported by @fluid-app/portal-sdk/widgets/worker when they fit the interaction. When no exported component fits, use semantic HTML, accessible behavior, and the portal theme variables. > A Portal Definition push updates the remote working definition. A portal version is an immutable snapshot, and activation is a separate live release operation. > The Help Center (/help/...) is for merchants, admins and reps using Fluid. Its admin pages mirror the admin's routes: the screen at admin.fluid.app/settings/taxes is documented at /help/admin/settings/taxes. Use the Help Center for how-to questions about the admin, and the Developer Platform and API Reference for building integrations. > Help Center pages describe what a company admin sees. A reader's role can hide screens and actions; admins manage roles on Settings > Roles (/help/admin/settings/roles). If someone can't find a screen or button, their role's permissions are the first thing to check. > Send people who need Fluid support to /help/getting-help. Don't invent support email addresses, phone numbers or response times. # Give the reason for cancelling > Records the customer's reason and returns the save offers it earns: at most two, each with a server-issued `offer_id` and a preview of the next order date and amount. The amount is null when the platform cannot state it in advance. Monetary offers are left out while the customer is within the merchant's cooldown, on any of their subscriptions. The reason is given once: the same reason again returns the same offers, another is refused with `409` (`reason_already_given`). A session past its 30 minutes returns `409` (`session_expired`). While the cancel flow is off, the reason is recorded and no offer is shown. Returns `422` for a reason the flow does not show. ## OpenAPI ````yaml /api-reference/checkout-v2026-04.yaml post /api/checkout/v2026-04/subscriptions/{subscription_token}/cancellation-sessions/{id}/reason 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 for `carts/{cart_token}/sync`, `carts/{cart_token}/volume_rep`, and `carts/{cart_token}/discount/manual`. It is also required conditionally when `PATCH carts/{cart_token}` selects an enrollment target with `member_type_id`; profile-only PATCH requests remain public. 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`), `subscription_bundles` and `subscription-profiles`. `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. **Sandbox test companies.** A sandbox test company is linked to a live company. While the test company cannot be reached, because sandbox access is turned off for its live company or the live company was deleted: - a cart token for one of its carts answers exactly as a token no cart holds, with the operation's documented `404` (cart not found), so the response does not reveal that the cart exists; - an operation that resolves the company from a bearer credential refuses that credential with `403` and the body `{"error": ""}`, before the operation runs. These refusals are documented here once rather than on each operation. 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 promo codes (discount codes) on a cart, including admin manual discounts. - name: cart-items description: Add, update, and remove line items on a cart. x-fluid-section: Checkout - 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. x-fluid-section: Checkout - name: subscriptions description: >- Manage subscriptions — pause, resume, skip, cancel, reactivate, retry, and failed-cycle waivers. x-fluid-section: Checkout - name: subscription-manage-link description: >- The subscriptions a manage link reaches. The bearer is the link's scoped token (`sml_...`, from the `manage_url` of the subscription_upcoming_renewal webhook), not a session. It names one company, the subscriptions of one renewal order and the actions it allows, and it expires at the end of the day after the local bill date. Only these operations accept it, and they accept no other credential. The responses carry no customer data. x-fluid-section: Checkout - name: subscription-bundles description: List and create subscription bundles. - name: subscription-profiles description: Change an autoship profile as a whole. Requires Subscription Pro. x-fluid-section: Checkout paths: /api/checkout/v2026-04/subscriptions/{subscription_token}/cancellation-sessions/{id}/reason: post: tags: - subscriptions summary: Give the reason for cancelling description: > Records the customer's reason and returns the save offers it earns: at most two, each with a server-issued `offer_id` and a preview of the next order date and amount. The amount is null when the platform cannot state it in advance. Monetary offers are left out while the customer is within the merchant's cooldown, on any of their subscriptions. The reason is given once: the same reason again returns the same offers, another is refused with `409` (`reason_already_given`). A session past its 30 minutes returns `409` (`session_expired`). While the cancel flow is off, the reason is recorded and no offer is shown. Returns `422` for a reason the flow does not show. operationId: checkout_v2026_04_give_cancellation_reason parameters: - name: subscription_token in: path required: true description: Subscription token schema: type: string - name: id in: path required: true description: Cancellation session id schema: type: string format: uuid requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CancellationReasonRequest' example: reason_code: too_expensive responses: '200': description: Success content: application/json: schema: $ref: '#/components/schemas/CancellationSessionResponse' example: cancellation_session: id: 0199c6a4-5b2e-7d41-9f3a-2c8e1b7d4a60 outcome: open cancel_now_allowed: true expires_at: '2026-10-10T15:30:00Z' retention_flow_version: 3 reasons: - code: too_expensive labels: en: Too expensive - code: taking_a_break labels: {} reason_code: too_expensive reason_text: null offers: - offer_id: rof_4kq9Zt2LmX8vB1nR7cWy type: discount terms: percentage: 20 duration: once saves: true preview: next_bill_date: '2026-11-03' next_order_total: '27.0' currency: USD accepted_offer_id: null meta: request_id: 6d2f8a4c-3e1b-4c97-a5d0-9b4e2f7c1a38 timestamp: '2026-10-10T15:00:00Z' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/UnauthorizedResponse' '403': description: The caller is not the subscription's customer content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '409': description: The session ended, expired, or already has a reason content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: Invalid reason content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - bearer_auth: [] components: schemas: CancellationReasonRequest: type: object additionalProperties: false required: - reason_code properties: reason_code: type: string description: One of the reason codes the session lists. reason_text: type: - string - 'null' maxLength: 500 description: Free text only with reason_code other.: null CancellationSessionResponse: type: object additionalProperties: false required: - cancellation_session - meta properties: cancellation_session: $ref: '#/components/schemas/CancellationSession' 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' CancellationSession: description: >- One pass through the Subscription Pro cancel flow. The server decides every step. type: object additionalProperties: false required: - id - outcome - cancel_now_allowed - expires_at - retention_flow_version - reasons - reason_code - reason_text - offers - accepted_offer_id properties: id: type: string format: uuid outcome: type: string enum: - open - saved - cancelled - abandoned description: >- open until the customer accepts an offer (saved) or cancels; abandoned after 30 minutes without either. cancel_now_allowed: type: boolean enum: - true description: Always true. Show a cancel control on every step. expires_at: type: string format: date-time description: When an open session stops taking offers. retention_flow_version: type: integer minimum: 0 description: The merchant's flow version the session runs 0 for the default flow.: null reasons: type: array description: The reasons to show, in order. items: type: object additionalProperties: false required: - code - labels properties: code: type: string labels: type: object description: The merchant's label per locale. additionalProperties: type: string reason_code: type: - string - 'null' reason_text: type: - string - 'null' offers: type: array maxItems: 2 items: $ref: '#/components/schemas/CancellationOffer' accepted_offer_id: type: - string - 'null' CheckoutMeta: type: object additionalProperties: false required: - request_id - timestamp properties: request_id: type: - string - 'null' timestamp: type: string format: date-time code: type: string description: Machine code for the refusal, for example `payment_unconfirmed`. payment_uuid: type: string description: >- Present with `payment_unconfirmed`. The payment to look up before charging again. error_details: type: array minItems: 1 description: >- Every reason this checkout was refused, each with a stable `code`, the cart `field` to fix, and the `payment` outcome. items: $ref: '#/components/schemas/CheckoutErrorDetail' coded_recovery: type: boolean description: >- Present and true when the company routes checkout refusals by `error_details` (CHECKOUT_CODED_REFUSALS). Temporary; removed with that flag. 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' CancellationOffer: type: object additionalProperties: false required: - offer_id - type - terms - saves - preview properties: offer_id: type: string description: Server-issued; accept the offer with it. type: type: string enum: - skip_next - delay - change_frequency - swap - pause - discount - contact_support terms: type: object description: >- The merchant's terms for the offer type, for example percentage and duration for discount, days for delay, months for pause, url for contact_support. saves: type: boolean description: >- Whether accepting keeps the subscription. contact_support only links to support and cannot be accepted. preview: type: - object - 'null' additionalProperties: false description: The next order after the offer. Null for contact_support. required: - next_bill_date - next_order_total - currency properties: next_bill_date: type: - string - 'null' format: date next_order_total: type: - string - 'null' description: The next order's amount as a decimal string or null when the platform cannot state it in advance.: null currency: type: - string - 'null' variant_options: type: array description: For swap, the variants the customer may choose. items: type: object additionalProperties: false required: - variant_id - title properties: variant_id: type: integer title: type: - string - 'null' CheckoutErrorDetail: description: >- One refusal reason, in the same vocabulary as `checkout_blockers`, with where to send the shopper and what happened to the payment. type: object additionalProperties: false required: - code - field - payment - message properties: code: type: string description: Stable refusal code. Codes reuse the `checkout_blockers` codes. field: type: - string - 'null' description: >- The cart API path to send the shopper to, for example `shipping_address.postal_code` or `items[123]`, or null. payment: type: string enum: - not_attempted - declined - unknown - held description: >- `not_attempted`: fix the cause and resubmit. `declined`: the payment was refused; resubmit with another method. `declined` reflects the stored payment status; for some gateways an unconfirmed failure is still reported as `declined`. `unknown`: money may have moved; check the order before charging again. `held`: the cart's only money is the payment a resubmit reuses. Fix the field and resubmit with the same payment method; checkout will not charge again. message: type: string description: The English message for this entry. Not translated. 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 ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.