> ## 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. > 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or unversioned operation only when no newer versioned equivalent exists — the company-v0 notes below list the known superseded operations. /api/company/v1 and /api/v1/... paths are documented in no spec here and must never be used (/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. > Navigation menu management is documented in themes/navigation-menus. These unversioned admin endpoints (/api/menus and nested menu_items) are verified against the implementation but are not yet in the synced OpenAPI specs. Use that reference for menu payloads and its flat page/per_page pagination; missing spec coverage does not make these endpoints unavailable. > 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. # Metafields on storefront resources > Store custom data on storefront resources with metafields: the fields each one has, the value types, how writes merge and delete, and what shoppers can see. Metafields let you attach your own data to a storefront resource — a product's material, a post's reading time, a page's accent colour. Each metafield is a typed value filed under a `namespace` and a `key`. Metafields are public. The public storefront endpoints return every metafield on a resource, to anyone. Never store private, internal, or personal data in them. ## Read metafields Every storefront response includes a `metafields` array. It's empty when the resource has none: ```json theme={null} "metafields": [ { "namespace": "custom", "key": "reading_time", "value": "6 min", "value_type": "single_line_text_field", "description": "Estimated reading time shown under the title", "created_at": "2026-09-14T10:02:44Z", "updated_at": "2026-09-28T16:20:05Z", "locked": null } ] ``` The public and company endpoints return the same array. `value` comes back exactly as it was written: a number written as `"42"` reads back as the string `"42"`. ## Write metafields Send `metafields_attributes` on a company create or update. Each entry needs `namespace`, `key`, `value`, and `value_type`. `description` is optional. ```bash theme={null} curl -X PATCH "https://api.fluid.app/api/v202604/company/posts/7314" \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "post": { "metafields_attributes": [ { "namespace": "custom", "key": "reading_time", "value": "7 min", "value_type": "single_line_text_field" } ] } }' ``` How a write is applied: * **Matched by `namespace` and `key`.** An entry that matches an existing metafield replaces it. A new pair adds a metafield. * **Everything else is kept.** Metafields you don't send are left as they are. Omitting `metafields_attributes`, or sending `[]`, changes nothing. * **`description` is kept if you leave it out.** Send a new one to change it. * **All or nothing.** If any entry is invalid, the request returns `422` and none of the metafields change. ### Delete a metafield Send the entry with `_destroy: true`. `value` and `value_type` are still required, so include them: ```bash theme={null} curl -X PATCH "https://api.fluid.app/api/v202604/company/posts/7314" \ -H "Authorization: Bearer " \ -H "Content-Type: application/json" \ -d '{ "post": { "metafields_attributes": [ { "namespace": "custom", "key": "reading_time", "value": "7 min", "value_type": "single_line_text_field", "_destroy": true } ] } }' ``` There is no way to clear every metafield in one request. Delete them one entry at a time. ## Naming rules * `namespace`: up to 20 characters. `key`: up to 30 characters. * Both may contain only letters, digits, and underscores. * A `namespace` and `key` pair is unique on each resource. Group your own fields under one namespace, such as `custom` or your app's name, so they don't collide with anyone else's. ## Value types `value_type` says what kind of value a metafield holds. Fluid checks `value` against it: `"abc"` as a `number_integer` returns `422`. | Kind | `value_type` values | | - | - | | Text | `single_line_text_field` (up to 5,000 characters), `multi_line_text_field`, `rich_text_field` | | Numbers | `number_integer`, `number_decimal` | | Dates | `date`, `date_time` | | Other values | `boolean`, `color`, `url`, `json` | | Measurements | `weight`, `volume`, `dimension`, `rating`, `money` | | References | `file_reference`, `page_reference`, `product_reference`, `variant_reference`, `collection_reference`, `mixed_reference` | | Lists | `list.` followed by a text, number, date, colour, URL, or reference type — for example `list.single_line_text_field` | A few rules catch people out: * **`boolean`** takes JSON `true` or `false`. The string `"true"` is rejected. * **`color`** is `#RGB` or `#RRGGBB`. * **`url`** must start with `http://` or `https://`. * **Measurements** are objects with exact keys. For example, `money` is `{"amount": ..., "currency_code": ...}`. ## Metafield definitions A store can define its metafields in Fluid Admin: the type each `namespace` and `key` must have, and rules such as a minimum, a maximum, a list of allowed choices, or a pattern. When a definition matches a metafield you write, Fluid enforces it. A value of the wrong type, or one that breaks a rule, returns `422`. A definition never hides a metafield or makes it required. `locked` in a response shows whether the matching definition is locked in Fluid Admin, or `null` when there is no definition. ## Search, translation, and themes * **Search.** A list's `q` search matches metafield values. You can't filter a list by a metafield. * **Translation.** Metafields aren't translated. A translation PATCH (a write with a non-default `lang`) ignores `metafields_attributes`, except on products. See [Translations](/storefront/translations). * **Themes.** Liquid templates read product, variant, and enrollment pack metafields as `resource.metafields..`, for example `product.metafields.custom.material`. ## Current limitations Two resources don't follow the rules above yet: * **Collections** don't accept `metafields_attributes` through v2026-04. * **Products** can add a new metafield through v2026-04, but can't change or delete an existing one. Sending an existing `namespace` and `key` again returns `422`. ## Next steps * [Find and create resources](/storefront/find-and-create) — set metafields when you create a resource. * [Storefront resources](/storefront/resources) — the body key each resource uses.