> ## 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. The merchant must open the emailed sign-in link and create an API token before authenticated calls are possible. > 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or unversioned operation only when no newer versioned equivalent exists — the company-v0 notes below list the known superseded operations.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 where a spec documents it — in practice the unversioned company-v0 admin surface; every versioned surface uses cursor pagination. > 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 — 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. # Record that a Mist run is still alive > Mist Desktop calls this about every two minutes while a run works. It stamps `run_checked_in_at_ms` on every comment the run holds for the caller: a live root comment that is `handed` with this `run_id` and whose run the caller claimed. Reassigning the comment does not change who claimed the run. The stamp is a liveness marker, not an edit, so it does not change `lock_version`, and a cancel or backstop that follows still matches the version the caller observed. A check-in never moves the stamp backwards: one that carries an earlier time than the stored stamp leaves it as it was and still succeeds, because the run still holds the comment. An answer from Mist, which moves the comment to review, clears the stamp. The caller must be a person, since the run's claimer is the one user who may check in for it. A token with no user behind it is refused with 403. A client that sees the stamp go quiet can warn that Mist has not checked in. Nothing is released on silence; a person cancels. A run that holds no comment for the caller was canceled, answered, or claimed by another admin, or it was claimed before the claimer was recorded. That is a 409, which tells Mist Desktop the run was stopped elsewhere. Subscribers to the theme's comment stream are told to refetch after a check-in that stamped anything. ## OpenAPI ````yaml /api-reference/themes-v2026-04.yaml put /api/v202604/themes/{theme_id}/preview_comments/runs/{run_id}/check-in openapi: 3.1.0 info: title: Fluid Themes API description: | **The versioned themes surface.** Themes v0 (`/api/application_themes`) remains in place and unchanged — the theme editor and the Fluid CLI consume it and depend on its shape, including the heavy fields this version omits. That immovability is why this version exists: here the DEFAULT response is the lean one. Concretely, measured against production: - `GET /api/application_themes` returns the deprecated theme-level stylesheet columns on every row. For a three-theme company that is a 185KB response of which `global_stylesheet` alone is 182KB. - `GET /api/application_themes/active` renders every template with its Liquid `content`. On a 245-template theme that is 5.5MB, 96.5% of it template bodies, when callers typically need only `id`, `themeable_type` and `default` to resolve a single template. The path segment here is `themes`, not `application_themes`. **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, every operation in this API that resolves the company from the request's credential refuses a credential for it with `403` and the body `{"error": ""}`, before the operation runs. The refusal is documented here once rather than on each operation. version: v2026-04 contact: email: support@fluid.app servers: - url: https://api.fluid.app security: - bearer_auth: [] tags: - name: themes description: Theme listing and the active theme. - name: preview comments description: |- Comments pinned to an element on a theme's preview, and their replies. A comment is addressed by the client-generated `client_id` rather than a row id: that is the identity every client already holds, so a retry after a dropped response is the same request rather than a new one. Creating a comment or a reply twice under one id is a success that changes nothing. There is one route per operation rather than a single write of the whole comment set. `status` is a last-writer-wins register keyed on `status_at_ms`, so a write carrying an older stamp than the stored one is accepted and discarded — it answers 200 with the status unchanged, because the request did what the contract says. paths: /api/v202604/themes/{theme_id}/preview_comments/runs/{run_id}/check-in: parameters: - name: theme_id in: path required: true description: Id of the theme whose comments the run holds. schema: type: integer - name: run_id in: path required: true description: >- Identity of the run checking in, as allocated when it claimed its comments. schema: type: string minLength: 1 maxLength: 255 pattern: ^[A-Za-z0-9_-]+$ put: tags: - preview comments summary: Record that a Mist run is still alive description: |- Mist Desktop calls this about every two minutes while a run works. It stamps `run_checked_in_at_ms` on every comment the run holds for the caller: a live root comment that is `handed` with this `run_id` and whose run the caller claimed. Reassigning the comment does not change who claimed the run. The stamp is a liveness marker, not an edit, so it does not change `lock_version`, and a cancel or backstop that follows still matches the version the caller observed. A check-in never moves the stamp backwards: one that carries an earlier time than the stored stamp leaves it as it was and still succeeds, because the run still holds the comment. An answer from Mist, which moves the comment to review, clears the stamp. The caller must be a person, since the run's claimer is the one user who may check in for it. A token with no user behind it is refused with 403. A client that sees the stamp go quiet can warn that Mist has not checked in. Nothing is released on silence; a person cancels. A run that holds no comment for the caller was canceled, answered, or claimed by another admin, or it was claimed before the claimer was recorded. That is a 409, which tells Mist Desktop the run was stopped elsewhere. Subscribers to the theme's comment stream are told to refetch after a check-in that stamped anything. operationId: checkInThemePreviewCommentRun responses: '200': description: The check-in was recorded. content: application/json: schema: type: object required: - run - status - meta properties: run: type: object description: What the check-in reached. required: - run_id - checked_in_at_ms - comment_count properties: run_id: type: string description: The run that checked in. checked_in_at_ms: type: integer description: >- The time this check-in carried, in milliseconds since the epoch. A comment whose stamp was already later keeps its later stamp. comment_count: type: integer minimum: 1 description: >- How many comments the run holds for the caller and matched. status: type: integer description: HTTP status, repeated in the body. meta: $ref: '#/components/schemas/PreviewCommentResponseMeta' example: run: run_id: run_01J8Z3K4QF7M2V9XB6T0RC5HWD checked_in_at_ms: 1789464485000 comment_count: 1 status: 200 meta: request_uuid: 7c1e9a52-4b3d-4f0e-9d2a-81f6c3b5e240 timestamp: '2026-09-15T09:28:05Z' '401': description: Authentication is required. '403': description: >- A company admin with theme update permission is required, and a person behind the request, who is the run's claimer. '404': description: The theme is unavailable. content: application/json: schema: oneOf: - $ref: '#/components/schemas/PreviewCommentError' - type: object required: - error additionalProperties: false properties: error: type: string enum: - Not found '409': description: >- The run holds no comment for the caller. It was canceled, answered, or claimed by another admin, or it was claimed before the claimer was recorded. content: application/json: schema: $ref: '#/components/schemas/PreviewCommentError' example: error: message: This run no longer holds any comment. details: type: conflict status: 409 meta: request_uuid: 7c1e9a52-4b3d-4f0e-9d2a-81f6c3b5e240 timestamp: '2026-09-15T09:28:05Z' '422': description: The run id is invalid. content: application/json: schema: $ref: '#/components/schemas/PreviewCommentError' security: - bearer_auth: [] components: schemas: PreviewCommentResponseMeta: type: object description: Envelope metadata returned on every preview-comment response. properties: request_uuid: type: - string - 'null' description: Correlation id for this request, when one was assigned. timestamp: type: string format: date-time description: When the response was built. required: - request_uuid - timestamp PreviewCommentError: type: object description: The error envelope returned by the preview-comment routes. properties: error: type: object description: What went wrong. properties: message: type: string description: Human-readable description of the failure. details: type: object description: |- Machine-readable detail. Carries `type` — the failure's symbol, such as `not_found` or `validation_failed` — when the failure came from the domain rather than from parameter validation. required: - message - details status: type: integer description: HTTP status, repeated in the body. meta: $ref: '#/components/schemas/PreviewCommentResponseMeta' required: - error - status - meta securitySchemes: bearer_auth: type: http scheme: bearer ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.