> ## 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 <token>; public storefront read endpoints require no auth.
> To sign a new merchant up for Fluid programmatically, run `fluid signup` from the Fluid CLI, or 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or unversioned operation only when no newer versioned equivalent exists — the company-v0 notes below list the known superseded operations.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.

# Measure and improve theme performance

> Read a storefront page's latest Lighthouse result, fix what it finds in your theme, scan again, and report the change.

Fluid runs Lighthouse scans on your storefront pages and keeps the latest result for each one. Use those results to find what slows a page down, fix it in your theme, and show the difference.

## What Fluid scans

Fluid scans the public storefront page of these items: products, enrollment packs, categories, collections, pages, posts, playlists, and media items. A scan measures the page the way a shopper on a phone loads it, using Google PageSpeed with the mobile form factor. Fluid loads the page once first, so the measurement reads a cached page rather than its first build.

A scan measures the live page, so it measures your published theme. Changes in an unpublished theme or a `fluid theme dev` development theme don't show up in a scan until you publish them.

Fluid queues a scan when you create or update one of these items. Changing your theme doesn't change the items, so after a theme change you request the scan yourself.

## Read the latest result

Get the latest result for the item behind the page, for example a product:

```bash theme={null}
curl "https://api.fluid.app/api/v202604/company/products/48213/lighthouse" \
  -H "Authorization: Bearer <token>"
```

The result carries three summaries, worked out from the full Lighthouse report that comes with them:

* **Category scores**, from 0 to 100, for performance, accessibility, best practices and SEO.
* **Core metrics**, such as Largest Contentful Paint, Cumulative Layout Shift and Total Blocking Time, with a `good`, `needs-improvement` or `poor` rating where Lighthouse gives one.
* **Optimization opportunities**: the audits that found savings, largest saving first. Start at the top of this list.

Any value can be empty when the run didn't produce it. When no scan exists yet, the request starts one and tells you to check back. See the reference pages for each item type:

| Item | Latest result | Request a scan |
| - | - | - |
| Product | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-product.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-product.md) |
| Enrollment pack | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-an-enrollment-pack.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-an-enrollment-pack.md) |
| Category | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-category.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-category.md) |
| Collection | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-collection.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-collection.md) |
| Page | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-page.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-page.md) |
| Post | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-post.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-post.md) |
| Playlist | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-playlist.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-playlist.md) |
| Media item | [Latest result](https://docs.fluid.app/api-reference/company/latest-lighthouse-result-for-a-media-item.md) | [Scan](https://docs.fluid.app/api-reference/company/trigger-a-lighthouse-scan-for-a-media-item.md) |

## Fix what the scan finds

Each opportunity has a Lighthouse audit ID. These are the ones a theme most often causes, and the theme fix for each:

| Audit ID | What to change in your theme |
| - | - |
| `uses-optimized-images`, `modern-image-formats`, `uses-responsive-images` | Request a rendition sized for the layout with the [`image_url` filter](https://docs.fluid.app/themes/image-transformations), for example `width: 800, format: "auto"`, or render the image with the [`media_tag` filter](https://docs.fluid.app/themes/media-tag), which builds a `srcset` for you. Set `sizes` to the width the image really takes up. |
| `offscreen-images` | Lazy-load images below the first screen. `media_tag` adds `loading="lazy"` by default. |
| `largest-contentful-paint-element`, `lcp-lazy-loaded` | Don't lazy-load the hero image or the first product image. Pass `loading: "eager"` to `media_tag` for that one image. |
| `unsized-images`, `layout-shifts` | Give images a `width` and `height`, or a fixed aspect ratio in CSS, so the page doesn't move as they load. `media_tag` adds both attributes when it knows the image's size. |
| `render-blocking-resources` | Load scripts with `defer` or `async`, and keep only the CSS the first screen needs in the `<head>`. Check app embeds and other markup in the head too. See [Common pitfalls](https://docs.fluid.app/themes/common-pitfalls.md) for what puts markup in the `<head>`. |
| `unused-javascript`, `unused-css-rules` | Remove libraries and stylesheets the page doesn't use, or load them only on the templates that need them. |

Large media files slow every page that shows them. Compress images and videos before you upload them to the DAM.

## Scan again and compare

**1. Record the starting point**

Before you change anything, read the latest result and note its scan time, the performance score, and the core metrics you plan to improve.

**2. Publish the fix**

Make the change in your theme and publish it, so the live page carries it.

**3. Request a scan**

```bash theme={null}
curl -X POST "https://api.fluid.app/api/v202604/company/products/48213/lighthouse" \
  -H "Authorization: Bearer <token>"
```

The scan runs in the background. Wait a few minutes, then read the latest result again.

**4. Check that the result is new**

Compare the result's scan time with the one you recorded. Fluid skips a requested scan when one ran in the last few minutes or the scanner is busy, and then you get the earlier result back. If the time hasn't changed, request the scan again later.

**5. Report before and after**

Report the page URL, both scan times, and the before and after values for the performance score and each metric you targeted.

Lighthouse scores vary from run to run. Compare a few scans before you call a small change an improvement.

## Related pages

* [Image transformations](https://docs.fluid.app/themes/image-transformations.md)
* [Render responsive media](https://docs.fluid.app/themes/media-tag.md)
* [Query parameters and caching](https://docs.fluid.app/themes/query-parameters-and-caching.md)
* [Common pitfalls](https://docs.fluid.app/themes/common-pitfalls.md)


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