From a6e133ceabb7d804483ee072eaf20077d89fcf2b Mon Sep 17 00:00:00 2001
From: Jarek Radosz <jarek@cvx.dev>
Date: Thu, 3 Sep 2026 08:57:28 +0200
Subject: [PATCH] DEV: Introduce warpdrive store (with compat layer) and
 migrate some models (#42147)

Adds a WarpDrive store (`service:warp-store`, LegacyMode + JSON:API
cache) alongside the existing `service:store`, routing requests through
Discourse's `ajax()` helper.

`RestCompatModel` bridges legacy `RestModel` callsites
(`get`/`set`/`setProperties`, `store.createRecord`, `save`,
`destroyRecord`) onto it.

Converts **badge, user-badge, topic-details, bookmark, tag, tag-group,
tag-info, tag-notification, tag-settings and archetype**, with per-model
schemas, request builders and payload normalizers.

Attributes outside a schema (plugin `add_to_serializer` fields, ad-hoc
`create` keys) are retained separately so nothing the server sends is
dropped.
---
 .skills/discourse-warpdrive-models/SKILL.md   |  91 +++++
 AI-AGENTS.md                                  |   1 +
 .../admin/controllers/admin-user/badges.js    |  12 +-
 .../admin/routes/admin-user/badges.js         |   2 +-
 .../admin/templates/admin-user/badges.gjs     |   2 +-
 frontend/discourse/app/app.js                 |   1 +
 .../app/components/modal/grant-badge.gjs      |   7 +-
 .../discourse/app/data/builders/badges.js     |  43 +++
 .../discourse/app/data/builders/bookmarks.js  |  21 +
 .../discourse/app/data/builders/helpers.js    |  39 ++
 .../app/data/builders/topic-details.js        |  25 ++
 .../app/data/builders/user-badges.js          |  50 +++
 .../discourse/app/data/extra-attributes.js    |  58 +++
 .../app/data/handlers/discourse-rest.js       |  27 ++
 frontend/discourse/app/data/jsonapi-utils.js  |  65 ++++
 frontend/discourse/app/data/normalize.js      | 180 +++++++++
 frontend/discourse/app/data/rest-compat.js    | 255 +++++++++++++
 .../discourse/app/data/schemas/archetype.js   |   9 +
 .../app/data/schemas/badge-grouping.js        |  16 +
 .../discourse/app/data/schemas/badge-type.js  |   7 +
 frontend/discourse/app/data/schemas/badge.js  |  38 ++
 .../discourse/app/data/schemas/bookmark.js    |  55 +++
 .../discourse/app/data/schemas/helpers.js     |  16 +
 frontend/discourse/app/data/schemas/index.js  |  28 ++
 .../discourse/app/data/schemas/tag-group.js   |  13 +
 .../discourse/app/data/schemas/tag-info.js    |  22 ++
 .../app/data/schemas/tag-notification.js      |  10 +
 .../app/data/schemas/tag-settings.js          |  21 +
 frontend/discourse/app/data/schemas/tag.js    |  24 ++
 .../app/data/schemas/topic-details.js         |  47 +++
 .../discourse/app/data/schemas/user-badge.js  |  27 ++
 .../discourse/app/data/warp-rest-model.js     | 198 ++++++++++
 .../discourse/app/lib/grant-badge-utils.js    |  41 +-
 .../discourse/app/lib/model-extensions.js     |  43 ++-
 frontend/discourse/app/models/archetype.js    |  14 +-
 .../discourse/app/models/badge-grouping.js    |   8 +-
 frontend/discourse/app/models/badge.js        | 137 ++-----
 frontend/discourse/app/models/bookmark.js     | 142 ++++---
 frontend/discourse/app/models/tag-group.js    |  12 +-
 frontend/discourse/app/models/tag-info.js     |  23 +-
 .../discourse/app/models/tag-notification.js  |   9 +-
 frontend/discourse/app/models/tag-settings.js |  10 +-
 frontend/discourse/app/models/tag.js          |  18 +-
 .../discourse/app/models/topic-details.js     | 183 +++++----
 frontend/discourse/app/models/user-badge.js   | 235 +++++-------
 .../discourse/app/routes/topic/from-params.js |  45 ++-
 frontend/discourse/app/services/warp-store.js |  13 +
 frontend/discourse/babel.config.cjs           |   7 +
 frontend/discourse/package.json               |   5 +
 frontend/discourse/tests/setup-tests.js       |   2 +
 .../unit/lib/warp-model-extensions-test.js    | 358 ++++++++++++++++++
 .../tests/unit/models/topic-details-test.js   |  33 ++
 pnpm-lock.yaml                                | 133 +++++++
 53 files changed, 2378 insertions(+), 503 deletions(-)
 create mode 100644 .skills/discourse-warpdrive-models/SKILL.md
 create mode 100644 frontend/discourse/app/data/builders/badges.js
 create mode 100644 frontend/discourse/app/data/builders/bookmarks.js
 create mode 100644 frontend/discourse/app/data/builders/helpers.js
 create mode 100644 frontend/discourse/app/data/builders/topic-details.js
 create mode 100644 frontend/discourse/app/data/builders/user-badges.js
 create mode 100644 frontend/discourse/app/data/extra-attributes.js
 create mode 100644 frontend/discourse/app/data/handlers/discourse-rest.js
 create mode 100644 frontend/discourse/app/data/jsonapi-utils.js
 create mode 100644 frontend/discourse/app/data/normalize.js
 create mode 100644 frontend/discourse/app/data/rest-compat.js
 create mode 100644 frontend/discourse/app/data/schemas/archetype.js
 create mode 100644 frontend/discourse/app/data/schemas/badge-grouping.js
 create mode 100644 frontend/discourse/app/data/schemas/badge-type.js
 create mode 100644 frontend/discourse/app/data/schemas/badge.js
 create mode 100644 frontend/discourse/app/data/schemas/bookmark.js
 create mode 100644 frontend/discourse/app/data/schemas/helpers.js
 create mode 100644 frontend/discourse/app/data/schemas/index.js
 create mode 100644 frontend/discourse/app/data/schemas/tag-group.js
 create mode 100644 frontend/discourse/app/data/schemas/tag-info.js
 create mode 100644 frontend/discourse/app/data/schemas/tag-notification.js
 create mode 100644 frontend/discourse/app/data/schemas/tag-settings.js
 create mode 100644 frontend/discourse/app/data/schemas/tag.js
 create mode 100644 frontend/discourse/app/data/schemas/topic-details.js
 create mode 100644 frontend/discourse/app/data/schemas/user-badge.js
 create mode 100644 frontend/discourse/app/data/warp-rest-model.js
 create mode 100644 frontend/discourse/app/services/warp-store.js
 create mode 100644 frontend/discourse/tests/unit/lib/warp-model-extensions-test.js

diff --git a/.skills/discourse-warpdrive-models/SKILL.md b/.skills/discourse-warpdrive-models/SKILL.md
new file mode 100644
index 00000000000..40d755ad551
--- /dev/null
+++ b/.skills/discourse-warpdrive-models/SKILL.md
@@ -0,0 +1,91 @@
+---
+name: discourse-warpdrive-models
+description: Use when creating a new WarpDrive-backed frontend model, or when reading, using, or changing a model already converted to WarpDrive (anything under frontend/discourse/app/data or extending RestCompatModel/WarpRestModel)
+---
+
+# WarpDrive models
+
+`service:warp-store` (`services/warp-store.js`) is a second data store alongside the legacy `service:store`, built on `@warp-drive/*` in LegacyMode with a JSON:API cache. Migrated models live in `frontend/discourse/app/data/`:
+
+- `schemas/` — one resource schema per type, registered in `schemas/index.js`
+- `normalize.js` + `jsonapi-utils.js` — Discourse REST payloads → JSON:API documents
+- `builders/` — request objects, one file per resource
+- `handlers/discourse-rest.js` — the sole network handler; routes through `ajax()`
+- `warp-rest-model.js` — `WarpRestModel` wrapper base, plus `warpStore()`, `requestMany`/`requestOne`, `defineFieldForwarders`
+- `rest-compat.js` — `RestCompatModel`, temporary legacy `RestModel` surface (`get`/`set`/`setProperties`, drafts, legacy adapter save path)
+- `extra-attributes.js` — retains payload keys no schema declares (migration safety net)
+
+A model is converted if its class in `app/models/` extends `RestCompatModel` (or `WarpRestModel` directly) and its schema is listed in `schemas/index.js`.
+
+## Note: Schemas must be complete
+
+A record is a proxy over the cache; reading a field the schema doesn't declare **throws in dev/test and returns `undefined` in production**. `Object.keys`, `for...in`, and `toJSON` see only schema fields. Therefore:
+
+- Declare more attributes than seems necessary — a field only one endpoint sends still needs a line.
+- To find every field, read the Ruby serializers (`app/serializers/`, including subclasses and `add_to_serializer` calls) and the API JSON schemas (`spec/requests/api/schemas/json/`) — not just one sample payload.
+- Anything still arriving via `extra-attributes.js` is unfinished work, not a pattern to rely on.
+
+## Creating a new model
+
+1. **Schema** — `data/schemas/<type>.js`, using `withDefaults` + `attrs`/`belongsTo` from `schemas/helpers.js`. Annotate with `/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */` (avoids a TS2883 d.ts issue). Register it in `schemas/index.js`.
+2. **Normalizer** — in `data/normalize.js` (or a per-resource file), build `{ data, included, meta }`. Use `resourceFrom(type, Schema, raw)` for the resource object (it also feeds the extras registry; pass an explicit `id` for sub-resources), `indexIncluded` + `maybeRelate` for relationships — `maybeRelate` drops pointers with no matching `included` entry, on purpose. Absent payload → `{ data: null }`, never `{ data: [] }` for single-record ops (wrap with the `recordOnly` pattern).
+3. **Builders** — `data/builders/<resource>.js` using `readMany`/`readOne`/`createOne`/`updateOne`/`deleteOne` from `builders/helpers.js`; they carry the `op` and the `data: { type, id }` the cache needs. RPC-style endpoints (toggles, bulk ops) are plain inline `{ url, method, options }` objects with no `op`.
+4. **Model class** — in `app/models/`, extend `RestCompatModel` (only extend `WarpRestModel` directly if no caller uses the legacy store/`get`/`set` API):
+
+   ```js
+   export default class Badge extends RestCompatModel {
+     static type = "badge";
+     static normalize = normalizeBadgesPayload;
+     static builders = {
+       list: findBadges,
+       one: findBadge,
+       save: saveBadge,
+       delete: deleteBadge,
+     };
+     // custom getters here take precedence over forwarders
+   }
+   defineFieldForwarders(Badge, BadgeSchema);
+   ```
+
+   Other subclass hooks:
+   - endpoints beyond plain CRUD — own statics over `requestMany`/`requestOne` (see `UserBadge.findByUsername`), not more `builders` keys
+   - `static munge(json)` — massages JSON on legacy `_hydrate`
+   - `primaryKey` — `TagNotification` uses `"name"`
+   - `__resource` override, for models with their own ingest path — call `_applyExtraAttributes(id)` after pushing, and read `__ownResource` in anything the base constructor reaches, since subclass fields aren't initialized during `super()`
+
+5. Run the model's qunit tests plus acceptance tests for its screens.
+
+Relations to **unmigrated** models (User, Topic, …) are not relationships: store the raw embedded object as a plain attribute (see `bookmark.js` `user`, or `userBadgeResource` inlining sideloads), optionally wrapping it in the legacy model class in a getter or `create`.
+
+## Working with a converted model
+
+Reading and mutating:
+
+- Fields are prototype forwarders to the cached record: `badge.name` reads, `badge.name = x` writes (LegacyMode records are mutable). Relationships are read-only through the wrapper.
+- Legacy `get("a.b")` / `set` / `setProperties` still work via `RestCompatModel`.
+- Ids are strings in the cache; the `@id` forwarder (`schema.identity.name`, usually `id`) coerces numeric ones back to numbers. `peekRecord` needs `String(id)`.
+- Wrap a nested cached resource in its own model class in a getter when callers need that class's getters (`get badge() { return new Badge(this.__resource.badge) }`).
+- Probe field existence by reading (`record.foo !== undefined`), never with `in` — the `has` trap on draft `trackedObject`s is unreliable and can hang headless qunit.
+- List results are arrays with document `meta` assigned onto them (`result.grant_count`).
+
+Fetching and persisting:
+
+- `Model.findAll(opts)` / `Model.findById(id)` — via `builders.list`/`one`. Anything else: `requestMany(this, someBuilder(...))` / `requestOne(...)`.
+- `Model.createFromJson(json)` — synchronous ingest for preloaded/embedded payloads; `record.updateFromJson(json)` re-pushes and re-adopts.
+- Legacy `store.createRecord(type, attrs)` still works: it produces a _draft_ wrapper (`__isLocalDraft`, attrs in a `trackedObject`, undeclared keys readable). After `save()` the wrapper adopts the cached record and strict schema reads apply.
+- `record.save(data)` has two paths: with `static builders.save` it goes through WarpDrive (`store.request`); without, it falls back to the legacy adapter pipeline. Both fire `addModelCallback` hooks and merge `addModelSaveProperty` extras.
+- `record.destroy()` (builder path) vs `record.destroyRecord()` (legacy adapter path).
+- One-off actions: `warpStore().request(someBuilder(...))` with an inline builder. A builder with no normalizer discards the response body (the handler returns `{ data: null }`) — callers needing it use `ajax` directly, as `UserBadge#revoke` does.
+- Optimistic updates: `store.push({ data: { type, id: String(id), attributes } })`, then `this._adoptResource(this.id)` so a draft wrapper sees the new value; push the previous attributes back if the request rejects (`UserBadge#favorite`).
+
+Plugin-extension APIs (`api.addModelField`/`Getter`/`Method`/…) still work — fields land as tracked properties on the wrapper, not in the cache. Schema-contributed plugin fields are planned but **not built** — don't design anything that depends on them.
+
+## Changing a converted model
+
+- **New server field**: add one line to the schema (`attrs(...)`) — `resourceFrom` picks it up automatically.
+- **New client-only field**: also declare it in the schema (cheap, and keeps reads legal); mark it with a comment saying who sets it.
+- **New relationship**: schema `belongsTo` + normalizer `maybeRelate` + push the related resource into `included`. Only between migrated types.
+- **New endpoint**: add a builder; CRUD shapes use `builders/helpers.js`, RPC shapes are inline objects.
+- **Derived values**: plain getters on the model class — define them before `defineFieldForwarders` runs. It skips any name that resolves anywhere on the prototype chain, which is also what stops a legacy-derived schema field called `save`/`get`/`destroy` from shadowing a base method.
+- Prefer data-layer fixes (normalizer, schema, builder, compat layer) over touching consumers (routes, controllers, components) — the migration's goal is unchanged call sites.
+- Shedding `RestCompatModel` for a model is the end state: only after no caller uses `get`/`set`/`store.createRecord`/legacy `save`.
diff --git a/AI-AGENTS.md b/AI-AGENTS.md
index 852238e8672..bb8a7d93279 100644
--- a/AI-AGENTS.md
+++ b/AI-AGENTS.md
@@ -22,6 +22,7 @@ Discourse is large with long history. Understand context before changes.
 - Make display strings translatable (use placeholders, not split strings)
 - Use "Sentence case" for strings, not "Proper Case" or "lower case"
 - Plugins/themes can't import npm modules directly; add the dependency to core and expose a `frontend/discourse/app/lib/load-*.js` wrapper that does the `import()` (see `load-morphlex.js`).
+- Use the skill at `.skills/discourse-warpdrive-models` when creating or changing WarpDrive-backed models (`frontend/discourse/app/data`)
 
 ### Comments & Types
 - Prefer self-documenting code. Comments should only be added when future misunderstanding is likely. They should be terse, and should describe 'why', not 'what'. They should not be used to describe history.
diff --git a/frontend/discourse/admin/controllers/admin-user/badges.js b/frontend/discourse/admin/controllers/admin-user/badges.js
index 39aa54ba479..11804a89c7c 100644
--- a/frontend/discourse/admin/controllers/admin-user/badges.js
+++ b/frontend/discourse/admin/controllers/admin-user/badges.js
@@ -11,7 +11,10 @@ import {
   arraySortedByProperties,
   removeValueFromArray,
 } from "discourse/lib/array-tools";
-import { grantableBadges } from "discourse/lib/grant-badge-utils";
+import {
+  grantableBadgeOptions,
+  grantableBadges,
+} from "discourse/lib/grant-badge-utils";
 import { autoTrackedArray } from "discourse/lib/tracked-tools";
 import UserBadge from "discourse/models/user-badge";
 import { i18n } from "discourse-i18n";
@@ -61,6 +64,11 @@ export default class AdminUserBadgesController extends Controller {
     return grantableBadges(this.allBadges, this.userBadges);
   }
 
+  @dependentKeyCompat
+  get badgeOptions() {
+    return grantableBadgeOptions(this.availableBadges);
+  }
+
   get groupedBadges() {
     const allBadges = this.model;
 
@@ -128,7 +136,7 @@ export default class AdminUserBadgesController extends Controller {
         // Update the selected badge ID after the combobox has re-rendered.
         const newSelectedBadge = this.availableBadges[0];
         if (newSelectedBadge) {
-          this.set("selectedBadgeId", newSelectedBadge.get("id"));
+          this.set("selectedBadgeId", newSelectedBadge.id);
         }
       });
     } catch (error) {
diff --git a/frontend/discourse/admin/routes/admin-user/badges.js b/frontend/discourse/admin/routes/admin-user/badges.js
index 54641783ef9..698d0cce1b9 100644
--- a/frontend/discourse/admin/routes/admin-user/badges.js
+++ b/frontend/discourse/admin/routes/admin-user/badges.js
@@ -20,7 +20,7 @@ export default class AdminUserBadgesRoute extends DiscourseRoute {
       if (badges.length > 0) {
         let grantableBadges = controller.availableBadges;
         if (grantableBadges.length > 0) {
-          controller.selectedBadgeId = grantableBadges[0].get("id");
+          controller.selectedBadgeId = grantableBadges[0].id;
         }
       }
     } finally {
diff --git a/frontend/discourse/admin/templates/admin-user/badges.gjs b/frontend/discourse/admin/templates/admin-user/badges.gjs
index fca303b4b6b..74ebf944815 100644
--- a/frontend/discourse/admin/templates/admin-user/badges.gjs
+++ b/frontend/discourse/admin/templates/admin-user/badges.gjs
@@ -44,7 +44,7 @@ export default <template>
               <label>{{i18n "admin.badges.badge"}}</label>
               <ComboBox
                 @value={{@controller.selectedBadgeId}}
-                @content={{@controller.availableBadges}}
+                @content={{@controller.badgeOptions}}
                 @onChange={{fn (mut @controller.selectedBadgeId)}}
                 @options={{hash filterable=true}}
               />
diff --git a/frontend/discourse/app/app.js b/frontend/discourse/app/app.js
index e802ad3a079..c0ef17a0a2f 100644
--- a/frontend/discourse/app/app.js
+++ b/frontend/discourse/app/app.js
@@ -6,6 +6,7 @@ import "./loader-shims";
 import "./ui-kit-shims";
 import "./module-shims";
 import "./discourse-common-loader-shims";
+import "@warp-drive/ember/install";
 import embroiderCompatModules from "@embroider/virtual/compat-modules";
 import { registerDiscourseImplicitInjections } from "discourse/lib/implicit-injections";
 import { registerSettings } from "discourse/lib/theme-settings-store";
diff --git a/frontend/discourse/app/components/modal/grant-badge.gjs b/frontend/discourse/app/components/modal/grant-badge.gjs
index d4c54395b6c..b00fc7f60b8 100644
--- a/frontend/discourse/app/components/modal/grant-badge.gjs
+++ b/frontend/discourse/app/components/modal/grant-badge.gjs
@@ -6,6 +6,7 @@ import didInsert from "@ember/render-modifiers/modifiers/did-insert";
 import { extractError } from "discourse/lib/ajax-error";
 import getURL from "discourse/lib/get-url";
 import {
+  grantableBadgeOptions,
   grantableBadges,
   isBadgeGrantable,
 } from "discourse/lib/grant-badge-utils";
@@ -32,6 +33,10 @@ export default class GrantBadgeModal extends Component {
     !this.availableBadges.length;
   }
 
+  get badgeOptions() {
+    return grantableBadgeOptions(this.availableBadges);
+  }
+
   get post() {
     return this.args.model.selectedPost;
   }
@@ -106,7 +111,7 @@ export default class GrantBadgeModal extends Component {
             <p>
               <ComboBox
                 @value={{this.selectedBadgeId}}
-                @content={{this.availableBadges}}
+                @content={{this.badgeOptions}}
                 @onChange={{fn (mut this.selectedBadgeId)}}
                 @options={{hash filterable=true none="badges.none"}}
               />
diff --git a/frontend/discourse/app/data/builders/badges.js b/frontend/discourse/app/data/builders/badges.js
new file mode 100644
index 00000000000..8644be81a10
--- /dev/null
+++ b/frontend/discourse/app/data/builders/badges.js
@@ -0,0 +1,43 @@
+import {
+  createOne,
+  deleteOne,
+  readMany,
+  readOne,
+  updateOne,
+} from "discourse/data/builders/helpers";
+import {
+  normalizeBadgeRecordPayload,
+  normalizeBadgesPayload,
+} from "discourse/data/normalize";
+import { applyQueryParams } from "discourse/lib/url";
+
+export function findBadges(opts = {}) {
+  const url = applyQueryParams("/badges.json", {
+    only_listable: opts.onlyListable ? "true" : null,
+  });
+  return readMany(url, normalizeBadgesPayload);
+}
+
+export function findBadge(id) {
+  return readOne(
+    `/badges/${encodeURIComponent(id)}`,
+    normalizeBadgeRecordPayload
+  );
+}
+
+export function saveBadge(badge, data) {
+  if (badge.id != null) {
+    return updateOne(
+      "badge",
+      badge.id,
+      `/admin/badges/${encodeURIComponent(badge.id)}`,
+      data,
+      normalizeBadgeRecordPayload
+    );
+  }
+  return createOne(`/admin/badges`, data, normalizeBadgeRecordPayload);
+}
+
+export function deleteBadge(id) {
+  return deleteOne("badge", id, `/admin/badges/${encodeURIComponent(id)}`);
+}
diff --git a/frontend/discourse/app/data/builders/bookmarks.js b/frontend/discourse/app/data/builders/bookmarks.js
new file mode 100644
index 00000000000..c48f3315e6c
--- /dev/null
+++ b/frontend/discourse/app/data/builders/bookmarks.js
@@ -0,0 +1,21 @@
+import { deleteOne } from "discourse/data/builders/helpers";
+
+export function deleteBookmark(id) {
+  return deleteOne("bookmark", id, `/bookmarks/${encodeURIComponent(id)}.json`);
+}
+
+export function togglePinBookmark(id) {
+  return {
+    url: `/bookmarks/${encodeURIComponent(id)}/toggle_pin`,
+    method: "PUT",
+  };
+}
+
+// `operation` is a `{ type, ...args }` object passed through as the body.
+export function bulkBookmarkOperation(bookmarkIds, operation) {
+  return {
+    url: `/bookmarks/bulk`,
+    method: "PUT",
+    options: { body: { bookmark_ids: bookmarkIds, operation } },
+  };
+}
diff --git a/frontend/discourse/app/data/builders/helpers.js b/frontend/discourse/app/data/builders/helpers.js
new file mode 100644
index 00000000000..cc42dd10be0
--- /dev/null
+++ b/frontend/discourse/app/data/builders/helpers.js
@@ -0,0 +1,39 @@
+// CRUD shorthands for per-resource builders. RPC-style endpoints (toggles,
+// notification updates, remove-allowed-X) skip these and use plain inline
+// request objects — they don't fit the CRUD shape.
+
+export function readMany(url, normalize) {
+  return { url, method: "GET", op: "query", options: { normalize } };
+}
+
+export function readOne(url, normalize) {
+  return { url, method: "GET", op: "findRecord", options: { normalize } };
+}
+
+export function createOne(url, body, normalize) {
+  return {
+    url,
+    method: "POST",
+    op: "createRecord",
+    options: { body, normalize },
+  };
+}
+
+export function updateOne(type, id, url, body, normalize) {
+  return {
+    url,
+    method: "PUT",
+    op: "updateRecord",
+    data: { type, id: String(id) },
+    options: { body, normalize },
+  };
+}
+
+export function deleteOne(type, id, url) {
+  return {
+    url,
+    method: "DELETE",
+    op: "deleteRecord",
+    data: { type, id: String(id) },
+  };
+}
diff --git a/frontend/discourse/app/data/builders/topic-details.js b/frontend/discourse/app/data/builders/topic-details.js
new file mode 100644
index 00000000000..52b17872d9e
--- /dev/null
+++ b/frontend/discourse/app/data/builders/topic-details.js
@@ -0,0 +1,25 @@
+// RPC-style endpoints; not CRUD, so they bypass `helpers.js`.
+
+export function updateTopicNotificationLevel(topicId, level) {
+  return {
+    url: `/t/${encodeURIComponent(topicId)}/notifications`,
+    method: "POST",
+    options: { body: { notification_level: level } },
+  };
+}
+
+export function removeAllowedTopicGroup(topicId, name) {
+  return {
+    url: `/t/${encodeURIComponent(topicId)}/remove-allowed-group`,
+    method: "PUT",
+    options: { body: { name } },
+  };
+}
+
+export function removeAllowedTopicUser(topicId, username) {
+  return {
+    url: `/t/${encodeURIComponent(topicId)}/remove-allowed-user`,
+    method: "PUT",
+    options: { body: { username } },
+  };
+}
diff --git a/frontend/discourse/app/data/builders/user-badges.js b/frontend/discourse/app/data/builders/user-badges.js
new file mode 100644
index 00000000000..0b2e3fc062c
--- /dev/null
+++ b/frontend/discourse/app/data/builders/user-badges.js
@@ -0,0 +1,50 @@
+import {
+  createOne,
+  deleteOne,
+  readMany,
+} from "discourse/data/builders/helpers";
+import {
+  normalizeUserBadgeRecordPayload,
+  normalizeUserBadgesPayload,
+} from "discourse/data/normalize";
+import { applyQueryParams } from "discourse/lib/url";
+
+// `/user-badges/:username` (dashed) and `/user_badges` (underscored) are
+// distinct Rails routes — not a typo.
+
+export function findUserBadgesByUsername(username, opts = {}) {
+  const url = applyQueryParams(
+    `/user-badges/${encodeURIComponent(username)}.json`,
+    { grouped: opts.grouped ? "true" : null }
+  );
+  return readMany(url, normalizeUserBadgesPayload);
+}
+
+export function findUserBadgesByBadgeId(badgeId, opts = {}) {
+  const url = applyQueryParams("/user_badges.json", {
+    badge_id: badgeId,
+    offset: opts.offset,
+    username: opts.username,
+  });
+  return readMany(url, normalizeUserBadgesPayload);
+}
+
+export function grantUserBadge(badgeId, username, reason) {
+  return createOne(
+    `/user_badges`,
+    { username, badge_id: badgeId, reason },
+    normalizeUserBadgeRecordPayload
+  );
+}
+
+export function deleteUserBadge(id) {
+  return deleteOne("user-badge", id, `/user_badges/${encodeURIComponent(id)}`);
+}
+
+// RPC-style: no `op` / `data` / normalizer.
+export function toggleFavoriteUserBadge(id) {
+  return {
+    url: `/user_badges/${encodeURIComponent(id)}/toggle_favorite`,
+    method: "PUT",
+  };
+}
diff --git a/frontend/discourse/app/data/extra-attributes.js b/frontend/discourse/app/data/extra-attributes.js
new file mode 100644
index 00000000000..24ce2c69caa
--- /dev/null
+++ b/frontend/discourse/app/data/extra-attributes.js
@@ -0,0 +1,58 @@
+import { trackedObject } from "@ember/reactive/collections";
+
+// Legacy `RestModel` kept whatever the server sent. A WarpDrive cache only
+// keeps what the schema declares, and core's schemas can't know about the
+// attributes plugins add (`add_to_serializer`) or the ad-hoc keys callers pass
+// to `create`. Those are retained here instead of being dropped, keyed by
+// identity so every wrapper around the same cached record reads the same
+// values.
+const registry = new Map();
+
+function keyFor(type, id) {
+  return `${type}:${id}`;
+}
+
+export function recordExtraAttributes(type, id, attributes) {
+  if (Object.keys(attributes).length === 0) {
+    return;
+  }
+
+  const key = keyFor(type, id);
+  let stored = registry.get(key);
+  if (!stored) {
+    stored = trackedObject({});
+    registry.set(key, stored);
+  }
+
+  Object.assign(stored, attributes);
+}
+
+export function extraAttributesFor(type, id) {
+  return registry.get(keyFor(type, id));
+}
+
+// Exposes `attributes` as own accessors on `target`. Names that already resolve
+// (a schema forwarder, a getter, a method) win and are left alone. Defining
+// accessors rather than copying values keeps later payloads visible: they land
+// in the same `attributes` object.
+export function exposeExtraAttributes(target, attributes) {
+  for (const name of Object.keys(attributes)) {
+    if (name in target) {
+      continue;
+    }
+
+    Object.defineProperty(target, name, {
+      configurable: true,
+      enumerable: true,
+      get: () => attributes[name],
+      set: (value) => {
+        attributes[name] = value;
+      },
+    });
+  }
+}
+
+// USE ONLY FOR TESTING PURPOSES.
+export function clearExtraAttributes() {
+  registry.clear();
+}
diff --git a/frontend/discourse/app/data/handlers/discourse-rest.js b/frontend/discourse/app/data/handlers/discourse-rest.js
new file mode 100644
index 00000000000..456a9aac3ac
--- /dev/null
+++ b/frontend/discourse/app/data/handlers/discourse-rest.js
@@ -0,0 +1,27 @@
+import { ajax } from "discourse/lib/ajax";
+
+const discourseRestHandler = {
+  async request(context, next) {
+    const request = context.request;
+    if (!request.url) {
+      return next(request);
+    }
+
+    const ajaxOptions = { type: (request.method ?? "GET").toUpperCase() };
+    const body = request.options?.body;
+    if (body !== undefined && body !== null) {
+      ajaxOptions.data = body;
+    }
+
+    const raw = await ajax(request.url, ajaxOptions);
+    const normalize = request.options?.normalize;
+    if (normalize) {
+      return normalize(raw);
+    }
+    // No normalizer (delete, custom actions) — `{ data: null }` is the only
+    // shape the cache validator accepts as a no-op.
+    return { data: null };
+  },
+};
+
+export default discourseRestHandler;
diff --git a/frontend/discourse/app/data/jsonapi-utils.js b/frontend/discourse/app/data/jsonapi-utils.js
new file mode 100644
index 00000000000..cdd44bc1c26
--- /dev/null
+++ b/frontend/discourse/app/data/jsonapi-utils.js
@@ -0,0 +1,65 @@
+import { recordExtraAttributes } from "discourse/data/extra-attributes";
+
+// Schemas are immutable module constants, so their field breakdown is computed
+// once rather than per normalized record.
+const schemaFields = new WeakMap();
+
+function fieldsFor(schema) {
+  let entry = schemaFields.get(schema);
+  if (!entry) {
+    const declared = new Set();
+    const attributes = [];
+    if (schema.identity?.name) {
+      declared.add(schema.identity.name);
+    }
+    for (const field of schema.fields ?? []) {
+      declared.add(field.name);
+      if (field.kind === "attribute") {
+        attributes.push(field.name);
+      }
+    }
+    entry = { declared, attributes };
+    schemaFields.set(schema, entry);
+  }
+  return entry;
+}
+
+// Builds the JSON:API resource object for `raw`: schema-declared attributes go
+// on the resource, the remaining keys are retained as extra attributes (see
+// `extra-attributes.js`). `id` defaults to `raw.id` — pass it explicitly for
+// sub-resources whose identity comes from the parent.
+export function resourceFrom(type, schema, raw, id = raw.id) {
+  id = String(id);
+  const { declared, attributes } = fieldsFor(schema);
+
+  const out = {};
+  for (const name of attributes) {
+    if (name in raw) {
+      out[name] = raw[name];
+    }
+  }
+
+  const extras = {};
+  for (const [name, value] of Object.entries(raw)) {
+    if (!declared.has(name)) {
+      extras[name] = value;
+    }
+  }
+  recordExtraAttributes(type, id, extras);
+
+  return { type, id, attributes: out };
+}
+
+export function indexIncluded(included) {
+  return new Set(included.map((r) => `${r.type}:${r.id}`));
+}
+
+// Add a relationship pointer only when the related resource is in
+// `includedIds` — referencing a missing identity logs a cache-validator
+// warning and leaves a dangling pointer on cold loads.
+export function maybeRelate(relationships, name, includedIds, type, id) {
+  if (id == null || !includedIds.has(`${type}:${id}`)) {
+    return;
+  }
+  relationships[name] = { data: { type, id: String(id) } };
+}
diff --git a/frontend/discourse/app/data/normalize.js b/frontend/discourse/app/data/normalize.js
new file mode 100644
index 00000000000..4235190a0b2
--- /dev/null
+++ b/frontend/discourse/app/data/normalize.js
@@ -0,0 +1,180 @@
+import {
+  indexIncluded,
+  maybeRelate,
+  resourceFrom,
+} from "discourse/data/jsonapi-utils";
+import { BadgeSchema } from "discourse/data/schemas/badge";
+import { BadgeGroupingSchema } from "discourse/data/schemas/badge-grouping";
+import { BadgeTypeSchema } from "discourse/data/schemas/badge-type";
+import { TopicDetailsSchema } from "discourse/data/schemas/topic-details";
+import { UserBadgeSchema } from "discourse/data/schemas/user-badge";
+import { badgeGroupingDisplayName } from "discourse/models/badge-grouping";
+
+function badgeResource(raw, includedIds) {
+  const resource = resourceFrom("badge", BadgeSchema, raw);
+  const relationships = {};
+  maybeRelate(
+    relationships,
+    "badge_type",
+    includedIds,
+    "badge-type",
+    raw.badge_type_id
+  );
+  maybeRelate(
+    relationships,
+    "badge_grouping",
+    includedIds,
+    "badge-grouping",
+    raw.badge_grouping_id
+  );
+  resource.relationships = relationships;
+  return resource;
+}
+
+function badgeTypeResource(raw) {
+  return resourceFrom("badge-type", BadgeTypeSchema, raw);
+}
+
+function badgeGroupingResource(raw) {
+  const resource = resourceFrom("badge-grouping", BadgeGroupingSchema, raw);
+  if (raw.name) {
+    resource.attributes.displayName = badgeGroupingDisplayName(raw.name);
+  }
+  return resource;
+}
+
+function userBadgeResource(raw, lookup, includedIds) {
+  const resource = resourceFrom("user-badge", UserBadgeSchema, raw);
+  const { attributes } = resource;
+  // Inline sideloads as plain objects so templates can read arbitrary fields
+  // without hitting LegacyMode's strict schema check on cached records.
+  if (raw.user_id != null) {
+    attributes.user = lookup.user(raw.user_id);
+  }
+  if (raw.granted_by_id != null) {
+    attributes.granted_by = lookup.user(raw.granted_by_id);
+  }
+  if (raw.topic_id != null) {
+    attributes.topic = lookup.topic(raw.topic_id);
+  }
+
+  const relationships = {};
+  maybeRelate(relationships, "badge", includedIds, "badge", raw.badge_id);
+  resource.relationships = relationships;
+  return resource;
+}
+
+function collectBadgeMetaIncluded(payload, included) {
+  for (const raw of payload.badge_types ?? []) {
+    included.push(badgeTypeResource(raw));
+  }
+  for (const raw of payload.badge_groupings ?? []) {
+    included.push(badgeGroupingResource(raw));
+  }
+}
+
+// Accepts:
+//   { badge: {...},  badge_types: [...], badge_groupings?: [...] }   (show)
+//   { badges: [...], badge_types: [...], badge_groupings: [...] }    (index)
+// A payload carrying neither is an empty collection, not an absent record:
+// badges ride along in larger payloads (a user summary, a post) that may
+// simply have none, and callers there expect a list. Only a missing payload
+// is `{ data: null }` (no `included` — JSON:API forbids it when data is null).
+export function normalizeBadgesPayload(payload) {
+  if (!payload) {
+    return { data: null };
+  }
+  const included = [];
+  collectBadgeMetaIncluded(payload, included);
+  const includedIds = indexIncluded(included);
+
+  if (payload.badge) {
+    return { data: badgeResource(payload.badge, includedIds), included };
+  }
+  return {
+    data: (payload.badges ?? []).map((raw) => badgeResource(raw, includedIds)),
+    included,
+  };
+}
+
+// Accepts:
+//   { user_badge: {...}, badges, badge_types, users, topics, granted_bies }      (grant POST)
+//   { user_badges: [...], badges, badge_types, users, topics, granted_bies }     (findByUsername)
+//   { user_badge_info: { user_badges, grant_count, username }, badges, ... }     (findByBadgeId)
+export function normalizeUserBadgesPayload(payload) {
+  if (!payload) {
+    return { data: null };
+  }
+  const included = [];
+  collectBadgeMetaIncluded(payload, included);
+  // Index BEFORE pushing sideloaded badges so each badge's relationships only
+  // reference badge-type / badge-grouping resources we actually included.
+  const badgeRelIds = indexIncluded(included);
+  for (const raw of payload.badges ?? []) {
+    included.push(badgeResource(raw, badgeRelIds));
+  }
+  const includedIds = indexIncluded(included);
+
+  const usersById = new Map();
+  for (const raw of [
+    ...(payload.users ?? []),
+    ...(payload.granted_bies ?? []),
+  ]) {
+    if (!usersById.has(raw.id)) {
+      usersById.set(raw.id, raw);
+    }
+  }
+  const topicsById = new Map();
+  for (const raw of payload.topics ?? []) {
+    topicsById.set(raw.id, raw);
+  }
+  const lookup = {
+    user: (id) => usersById.get(id),
+    topic: (id) => topicsById.get(id),
+  };
+
+  if (payload.user_badge) {
+    return {
+      data: userBadgeResource(payload.user_badge, lookup, includedIds),
+      included,
+    };
+  }
+
+  const wrapper = payload.user_badge_info;
+  const rawUserBadges = wrapper?.user_badges ?? payload.user_badges ?? [];
+  const doc = {
+    data: rawUserBadges.map((ub) => userBadgeResource(ub, lookup, includedIds)),
+    included,
+  };
+  if (wrapper) {
+    doc.meta = {
+      grant_count: wrapper.grant_count,
+      username: wrapper.username,
+    };
+  }
+  return doc;
+}
+
+// Single-record ops (findRecord / createRecord / updateRecord) must resolve to
+// exactly one resource, so a payload without the record key is a no-op rather
+// than an empty collection — `{ data: [] }` fails the cache validator.
+function recordOnly(normalize, rootKey) {
+  return (payload) =>
+    payload?.[rootKey] ? normalize(payload) : { data: null };
+}
+
+export const normalizeBadgeRecordPayload = recordOnly(
+  normalizeBadgesPayload,
+  "badge"
+);
+
+export const normalizeUserBadgeRecordPayload = recordOnly(
+  normalizeUserBadgesPayload,
+  "user_badge"
+);
+
+export function normalizeTopicDetailsPayload({ topicId, details }) {
+  return {
+    data: resourceFrom("topic-details", TopicDetailsSchema, details, topicId),
+  };
+}
diff --git a/frontend/discourse/app/data/rest-compat.js b/frontend/discourse/app/data/rest-compat.js
new file mode 100644
index 00000000000..8302ca73729
--- /dev/null
+++ b/frontend/discourse/app/data/rest-compat.js
@@ -0,0 +1,255 @@
+import { tracked } from "@glimmer/tracking";
+import {
+  get as emberGet,
+  getProperties as emberGetProperties,
+} from "@ember/object";
+import { trackedObject } from "@ember/reactive/collections";
+import { exposeExtraAttributes } from "discourse/data/extra-attributes";
+import WarpRestModel from "discourse/data/warp-rest-model";
+import {
+  applyModelCallbacks,
+  applyRegisteredFields,
+  extraSavePropertiesFor,
+  modelNameFor,
+} from "discourse/lib/model-extensions";
+
+// Attrs bags handed to `create`, as opposed to cached records. Tracked by
+// identity because the two are indistinguishable by shape, and reading an
+// undeclared field off a cached record throws rather than returning undefined.
+const draftResources = new WeakSet();
+
+// Bridges Discourse's legacy `Store` + `RestModel` callsites to WarpRestModel.
+// Drop this layer (extend WarpRestModel directly) once a model's callers no
+// longer use `.get` / `.set` / `.setProperties` / `store.createRecord` /
+// `record.save` / `record.destroyRecord`.
+export default class RestCompatModel extends WarpRestModel {
+  // Identity by default; legacy `service:store._hydrate` calls this on cache
+  // updates. Subclasses can override to massage JSON before it lands.
+  static munge(json) {
+    return json;
+  }
+
+  // Draft attrs go into a `trackedObject` so field reads/writes are reactive
+  // — Glimmer templates rerender when callers do `bookmark.set("name", ...)`,
+  // matching the old EmberObject behavior. Cached LegacyMode records have
+  // their own signal-based reactivity.
+  static create(attrs = {}) {
+    // Re-wrapping an existing instance was a harmless copy under EmberObject;
+    // the wrapper's attrs now live in a private resource, so a spread would
+    // drop them all. Hand the instance back instead.
+    if (attrs instanceof this) {
+      return attrs;
+    }
+
+    const resource = trackedObject({ ...attrs });
+    draftResources.add(resource);
+    const wrapper = new this(resource);
+    wrapper.store = attrs.store;
+    wrapper.__type = attrs.__type;
+    wrapper.__state = attrs.__state;
+    // Legacy `create(json)` took arbitrary keys; only schema fields have
+    // prototype forwarders, so expose the rest straight off the draft.
+    exposeExtraAttributes(wrapper, resource);
+    return wrapper;
+  }
+
+  @tracked isSaving = false;
+
+  // Subclasses override (e.g. `TagNotification` uses `"name"`).
+  primaryKey = "id";
+
+  // `Store._build` stamps these onto the raw attrs. They are legacy bookkeeping
+  // rather than schema fields, so — as in `RestModel` — they belong to the
+  // wrapper. Reading them back through `__resource` works only while it is the
+  // draft attrs bag: once the wrapper adopts a cached record, LegacyMode throws
+  // on every field the schema doesn't declare, and `save()` reads `isNew`.
+  store;
+  __type;
+  @tracked __state;
+
+  constructor() {
+    super(...arguments);
+
+    // Defines plugin-registered fields (see `addModelField`) as tracked
+    // properties on the wrapper. Plugin fields are outside the schema, so they
+    // live here rather than in the cache, and a caller/server-provided value
+    // wins over the registered default.
+    //
+    // Only a draft's attrs bag can be probed directly — it holds whatever the
+    // caller passed. A cached record throws on any field its schema doesn't
+    // declare, which is every plugin field, so go through the wrapper, where
+    // the base constructor has already exposed the retained extras. Existence
+    // is probed by reading rather than `in`: the `has` trap on a `trackedObject`
+    // draft is unreliable, and an explicit `undefined` means omission here.
+    //
+    // Reads `__ownResource`, not `__resource`: subclasses override the latter to
+    // resolve the resource from their own fields, which aren't initialized yet
+    // during `super()`.
+    applyRegisteredFields(this, (name) => {
+      const resource = this.__ownResource;
+      const value = draftResources.has(resource)
+        ? resource?.[name]
+        : this[name];
+      if (value !== undefined) {
+        return { value };
+      }
+    });
+
+    // Fires `init` callbacks (see `addModelCallback`) with the create args
+    // already in place, matching `RestModel`.
+    applyModelCallbacks(modelNameFor(this), "init", this);
+  }
+
+  // True until `save()` / `updateFromJson()` swaps in the cached record —
+  // `_adoptResource` replaces the draft attrs bag, which is never in the set.
+  get __isLocalDraft() {
+    return draftResources.has(this.__ownResource);
+  }
+
+  // Both "topicDetails" and "topic-details" resolve, and the plugin API keys
+  // its registrations by whichever spelling was used. `constructor.type` would
+  // apply a plugin's fields but silently drop its callbacks and save properties.
+  get #modelName() {
+    return modelNameFor(this);
+  }
+
+  get isNew() {
+    return this.__state === "new";
+  }
+
+  get isCreated() {
+    return this.__state === "created";
+  }
+
+  get(path) {
+    if (typeof path !== "string") {
+      return undefined;
+    }
+    return emberGet(this, path);
+  }
+
+  set(key, value) {
+    // Drafts: mutate the attrs bag directly. Cached records: route through
+    // the prototype setter, which writes to the record's own field.
+    if (this.__isLocalDraft) {
+      this.__resource[key] = value;
+      return value;
+    }
+    this[key] = value;
+    return value;
+  }
+
+  getProperties(...keys) {
+    return emberGetProperties(this, ...keys);
+  }
+
+  setProperties(hash) {
+    if (!hash) {
+      return hash;
+    }
+    for (const [key, value] of Object.entries(hash)) {
+      this.set(key, value);
+    }
+    return hash;
+  }
+
+  // Subclass hooks from `RestModel`. Fired by the legacy save path only — new
+  // code on the WarpDrive path uses `addModelCallback`.
+  beforeCreate() {}
+  afterCreate() {}
+
+  beforeUpdate() {}
+  afterUpdate() {}
+
+  // Legacy `RestModel#save`. Goes through the WarpDrive path when the subclass
+  // defines `static builders.save`; the legacy adapter pipeline otherwise.
+  async save(data) {
+    if (!this.constructor.builders?.save) {
+      return this.isNew ? this._saveNew(data) : this.update(data);
+    }
+
+    const props = this.#withSaveProperties(data);
+    return this.#withCallbacks(this.isNew ? "Create" : "Update", props, () =>
+      super.save(props)
+    );
+  }
+
+  // Runs `fn` between the registered `addModelCallback` before/after callbacks
+  // for `kind` ("Create" | "Update" | "Destroy").
+  async #withCallbacks(kind, props, fn) {
+    const modelName = this.#modelName;
+    await applyModelCallbacks(modelName, `before${kind}`, this, props);
+    const res = await fn();
+    await applyModelCallbacks(modelName, `after${kind}`, this, res);
+    return res;
+  }
+
+  // Merges plugin-registered save properties (see `addModelSaveProperty`) into
+  // the outgoing payload.
+  #withSaveProperties(data) {
+    const extras = extraSavePropertiesFor(this.#modelName, this);
+    return Object.keys(extras).length ? { ...data, ...extras } : data;
+  }
+
+  async _saveNew(props) {
+    props = this.#withSaveProperties(props);
+    return this.#withSaving(() => {
+      this.beforeCreate(props);
+      return this.#withCallbacks("Create", props, async () => {
+        const adapter = this.store.adapterFor(this.__type);
+        const res = await adapter.createRecord(this.store, this.__type, props);
+        if (res.payload) {
+          this.setProperties(this.constructor.munge(res.payload));
+          this.__state = "created";
+        }
+        res.target = this;
+        this.afterCreate(res);
+        return res;
+      });
+    });
+  }
+
+  async update(props) {
+    props = this.#withSaveProperties(props);
+    return this.#withSaving(() => {
+      this.beforeUpdate(props);
+      return this.#withCallbacks("Update", props, async () => {
+        const res = await this.store.update(
+          this.__type,
+          this[this.primaryKey],
+          props
+        );
+        const payload = this.constructor.munge(res.payload || res.responseJson);
+        if (payload && payload.success !== "OK") {
+          this.setProperties(payload);
+        }
+        res.target = this;
+        this.afterUpdate(res);
+        return res;
+      });
+    });
+  }
+
+  destroyRecord() {
+    return this.#withCallbacks("Destroy", undefined, () =>
+      this.store.destroyRecord(this.__type, this)
+    );
+  }
+
+  // `WarpRestModel#destroy` (builder-driven delete), wrapped with callbacks.
+  async destroy() {
+    await this.#withCallbacks("Destroy", undefined, () => super.destroy());
+  }
+
+  async #withSaving(fn) {
+    if (this.isSaving) {
+      return Promise.reject(new Error("model is already saving"));
+    }
+    this.isSaving = true;
+    try {
+      return await fn();
+    } finally {
+      this.isSaving = false;
+    }
+  }
+}
diff --git a/frontend/discourse/app/data/schemas/archetype.js b/frontend/discourse/app/data/schemas/archetype.js
new file mode 100644
index 00000000000..cb7634dec95
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/archetype.js
@@ -0,0 +1,9 @@
+import { attrs, withDefaults } from "./helpers";
+
+// `site` is stamped on at runtime by `Site.create` so `isDefault` can compare
+// against `this.site.default_archetype`.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const ArchetypeSchema = withDefaults({
+  type: "archetype",
+  fields: [...attrs("name", "options", "site")],
+});
diff --git a/frontend/discourse/app/data/schemas/badge-grouping.js b/frontend/discourse/app/data/schemas/badge-grouping.js
new file mode 100644
index 00000000000..65d1ad90c78
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/badge-grouping.js
@@ -0,0 +1,16 @@
+import { attrs, withDefaults } from "./helpers";
+
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const BadgeGroupingSchema = withDefaults({
+  type: "badge-grouping",
+  fields: [
+    ...attrs(
+      "name",
+      "description",
+      "position",
+      "system",
+      // Server doesn't ship `displayName` — populated at normalize time via i18n.
+      "displayName"
+    ),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/badge-type.js b/frontend/discourse/app/data/schemas/badge-type.js
new file mode 100644
index 00000000000..3cb763ece02
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/badge-type.js
@@ -0,0 +1,7 @@
+import { attrs, withDefaults } from "./helpers";
+
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const BadgeTypeSchema = withDefaults({
+  type: "badge-type",
+  fields: [...attrs("name", "sort_order")],
+});
diff --git a/frontend/discourse/app/data/schemas/badge.js b/frontend/discourse/app/data/schemas/badge.js
new file mode 100644
index 00000000000..9728606a136
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/badge.js
@@ -0,0 +1,38 @@
+import { attrs, belongsTo, withDefaults } from "./helpers";
+
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const BadgeSchema = withDefaults({
+  type: "badge",
+  fields: [
+    ...attrs(
+      "name",
+      "description",
+      "long_description",
+      "slug",
+      "icon",
+      "image_url",
+      "grant_count",
+      "enabled",
+      "listable",
+      "show_in_post_header",
+      "has_badge",
+      "allow_title",
+      "multiple_grant",
+      "manually_grantable",
+      "system",
+      // FKs alongside the relations so callers can read them directly.
+      "badge_type_id",
+      "badge_grouping_id",
+      // AdminBadgeSerializer-only — declared so the cache preserves them.
+      "query",
+      "trigger",
+      "target_posts",
+      "auto_revoke",
+      "show_posts",
+      "i18n_name",
+      "image_upload_id"
+    ),
+    belongsTo("badge_type", "badge-type"),
+    belongsTo("badge_grouping", "badge-grouping"),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/bookmark.js b/frontend/discourse/app/data/schemas/bookmark.js
new file mode 100644
index 00000000000..ac88d8ef06b
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/bookmark.js
@@ -0,0 +1,55 @@
+import { attrs, withDefaults } from "./helpers";
+
+// `user` is opaque — wrapped as a `User` instance in `Bookmark.create` rather
+// than treated as a relationship (User isn't migrated yet).
+//
+// `currentUser` and `topicStatus` are not schema fields — they're set as own
+// properties on the wrapper by `Bookmark.create` and the user-activity
+// controller's `transform`, respectively.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const BookmarkSchema = withDefaults({
+  type: "bookmark",
+  fields: [
+    ...attrs(
+      "name",
+      "created_at",
+      "updated_at",
+      "reminder_at",
+      "reminder_at_ics_start",
+      "reminder_at_ics_end",
+      "pinned",
+      "title",
+      "fancy_title",
+      "fancy_title_localized",
+      "locale",
+      "excerpt",
+      "bookmarkable_id",
+      "bookmarkable_type",
+      "bookmarkable_url",
+      "topic_id",
+      "linked_post_number",
+      "deleted",
+      "hidden",
+      "category_id",
+      "closed",
+      "archived",
+      "archetype",
+      "highest_post_number",
+      "bumped_at",
+      "slug",
+      "tags",
+      "tags_descriptions",
+      "truncated",
+      "post_id",
+      // Only on bookmarks embedded in topic-view payloads (TopicViewBookmarkSerializer).
+      "post_number",
+      "last_read_post_number",
+      "is_warning",
+      "invisible",
+      "user",
+      // Local-only — set by `Bookmark.createFor` and `BookmarkFormData.saveData`.
+      "auto_delete_preference",
+      "user_id"
+    ),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/helpers.js b/frontend/discourse/app/data/schemas/helpers.js
new file mode 100644
index 00000000000..689d6f8d3b7
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/helpers.js
@@ -0,0 +1,16 @@
+// Schemas annotate their export with `@type {LegacyResourceSchema}` so the
+// emitted `.d.ts` doesn't anchor through pnpm's `.pnpm/...` path (TS2883).
+export { withDefaults } from "@warp-drive/legacy/model/migration-support";
+
+export function attrs(...names) {
+  return names.map((name) => ({ kind: "attribute", name }));
+}
+
+export function belongsTo(name, type) {
+  return {
+    kind: "belongsTo",
+    name,
+    type,
+    options: { async: false, inverse: null },
+  };
+}
diff --git a/frontend/discourse/app/data/schemas/index.js b/frontend/discourse/app/data/schemas/index.js
new file mode 100644
index 00000000000..18b26a82484
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/index.js
@@ -0,0 +1,28 @@
+import { ArchetypeSchema } from "./archetype";
+import { BadgeSchema } from "./badge";
+import { BadgeGroupingSchema } from "./badge-grouping";
+import { BadgeTypeSchema } from "./badge-type";
+import { BookmarkSchema } from "./bookmark";
+import { TagSchema } from "./tag";
+import { TagGroupSchema } from "./tag-group";
+import { TagInfoSchema } from "./tag-info";
+import { TagNotificationSchema } from "./tag-notification";
+import { TagSettingsSchema } from "./tag-settings";
+import { TopicDetailsSchema } from "./topic-details";
+import { UserBadgeSchema } from "./user-badge";
+
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema[]} */
+export const schemas = [
+  ArchetypeSchema,
+  BadgeSchema,
+  BadgeTypeSchema,
+  BadgeGroupingSchema,
+  BookmarkSchema,
+  TagSchema,
+  TagGroupSchema,
+  TagInfoSchema,
+  TagNotificationSchema,
+  TagSettingsSchema,
+  TopicDetailsSchema,
+  UserBadgeSchema,
+];
diff --git a/frontend/discourse/app/data/schemas/tag-group.js b/frontend/discourse/app/data/schemas/tag-group.js
new file mode 100644
index 00000000000..27e231b53ad
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/tag-group.js
@@ -0,0 +1,13 @@
+import { attrs, withDefaults } from "./helpers";
+
+// TagGroup stays on the legacy `Store` + `RestAdapter` path (admin CRUD via
+// `record.save()` / `record.destroyRecord()`). Schema only powers the
+// wrapper's field forwarders. `tags` / `parent_tag` / `permissions` are
+// opaque payloads.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const TagGroupSchema = withDefaults({
+  type: "tag-group",
+  fields: [
+    ...attrs("name", "tags", "parent_tag", "one_per_topic", "permissions"),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/tag-info.js b/frontend/discourse/app/data/schemas/tag-info.js
new file mode 100644
index 00000000000..5ea28760d22
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/tag-info.js
@@ -0,0 +1,22 @@
+import { attrs, withDefaults } from "./helpers";
+
+// Loaded via `/tag/:id/info.json` (DetailedTagSerializer). Schema covers the
+// fields the legacy model exposed via `@tracked` / `@autoTrackedArray`.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const TagInfoSchema = withDefaults({
+  type: "tag-info",
+  fields: [
+    ...attrs(
+      "name",
+      "slug",
+      "description",
+      "topic_count",
+      "staff",
+      "category_restricted",
+      "categories",
+      "localizations",
+      "synonyms",
+      "tag_group_names"
+    ),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/tag-notification.js b/frontend/discourse/app/data/schemas/tag-notification.js
new file mode 100644
index 00000000000..4ff45c34f88
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/tag-notification.js
@@ -0,0 +1,10 @@
+import { attrs, withDefaults } from "./helpers";
+
+// Identity key for the legacy `Store.update` URL routing is `name`, not `id`
+// — the model sets `primaryKey = "name"` so `/tag/${name}/notifications.json`
+// resolves correctly when the user changes the notification level.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const TagNotificationSchema = withDefaults({
+  type: "tag-notification",
+  fields: [...attrs("name", "notification_level")],
+});
diff --git a/frontend/discourse/app/data/schemas/tag-settings.js b/frontend/discourse/app/data/schemas/tag-settings.js
new file mode 100644
index 00000000000..b9fff14aa5f
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/tag-settings.js
@@ -0,0 +1,21 @@
+import { attrs, withDefaults } from "./helpers";
+
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const TagSettingsSchema = withDefaults({
+  type: "tag-settings",
+  fields: [
+    ...attrs(
+      "name",
+      "slug",
+      "description",
+      "synonyms",
+      "tag_group_names",
+      "tag_groups",
+      "category_restricted",
+      "can_edit",
+      "can_admin",
+      "categories",
+      "localizations"
+    ),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/tag.js b/frontend/discourse/app/data/schemas/tag.js
new file mode 100644
index 00000000000..1d9c37e5e4d
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/tag.js
@@ -0,0 +1,24 @@
+import { attrs, withDefaults } from "./helpers";
+
+// Tag stays on the legacy `Store` + `RestAdapter` path; this schema only
+// powers the wrapper's field forwarders. `target_tag` / `localizations` are
+// opaque (their target models aren't migrated).
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const TagSchema = withDefaults({
+  type: "tag",
+  fields: [
+    ...attrs(
+      "name",
+      "slug",
+      "description",
+      "text",
+      "count",
+      "pm_count",
+      "pm_only",
+      "topic_count",
+      "staff",
+      "target_tag",
+      "localizations"
+    ),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/topic-details.js b/frontend/discourse/app/data/schemas/topic-details.js
new file mode 100644
index 00000000000..2f7483e02b0
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/topic-details.js
@@ -0,0 +1,47 @@
+import { attrs, withDefaults } from "./helpers";
+
+// Sub-resource owned by a Topic; identity = parent topic's id. Ships embedded
+// in the topic-view payload, not fetched standalone.
+//
+// `created_by`, `last_poster`, `participants`, `links`, `allowed_users`,
+// `allowed_groups` are opaque attributes — their target models aren't migrated.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const TopicDetailsSchema = withDefaults({
+  type: "topic-details",
+  fields: [
+    ...attrs(
+      "can_edit",
+      "can_move_posts",
+      "can_delete",
+      "can_permanently_delete",
+      "can_recover",
+      "can_remove_allowed_users",
+      "can_invite_to",
+      "can_invite_via_email",
+      "can_create_post",
+      "can_reply_as_new_topic",
+      "can_flag_topic",
+      "can_convert_topic",
+      "can_review_topic",
+      "can_edit_tags",
+      "can_publish_page",
+      "can_close_topic",
+      "can_archive_topic",
+      "can_split_merge_topic",
+      "can_edit_staff_notes",
+      "can_toggle_topic_visibility",
+      "can_pin_unpin_topic",
+      "can_banner_topic",
+      "can_moderate_category",
+      "can_remove_self_id",
+      "notification_level",
+      "notifications_reason_id",
+      "created_by",
+      "last_poster",
+      "participants",
+      "links",
+      "allowed_users",
+      "allowed_groups"
+    ),
+  ],
+});
diff --git a/frontend/discourse/app/data/schemas/user-badge.js b/frontend/discourse/app/data/schemas/user-badge.js
new file mode 100644
index 00000000000..b4a6cd35d95
--- /dev/null
+++ b/frontend/discourse/app/data/schemas/user-badge.js
@@ -0,0 +1,27 @@
+import { attrs, belongsTo, withDefaults } from "./helpers";
+
+// `user` / `granted_by` / `topic` are opaque attributes rather than relations
+// — those models aren't migrated yet; LegacyMode would throw on every unknown
+// field read against a cached `user` / `topic` record.
+/** @type {import("@warp-drive/core/types/schema/fields").LegacyResourceSchema} */
+export const UserBadgeSchema = withDefaults({
+  type: "user-badge",
+  fields: [
+    ...attrs(
+      "granted_at",
+      "created_at",
+      "count",
+      "post_id",
+      "post_number",
+      "grouping_position",
+      "topic_id",
+      "topic_title",
+      "is_favorite",
+      "can_favorite",
+      "user",
+      "granted_by",
+      "topic"
+    ),
+    belongsTo("badge", "badge"),
+  ],
+});
diff --git a/frontend/discourse/app/data/warp-rest-model.js b/frontend/discourse/app/data/warp-rest-model.js
new file mode 100644
index 00000000000..a910539657a
--- /dev/null
+++ b/frontend/discourse/app/data/warp-rest-model.js
@@ -0,0 +1,198 @@
+import {
+  exposeExtraAttributes,
+  extraAttributesFor,
+} from "discourse/data/extra-attributes";
+import { getOwnerWithFallback } from "discourse/lib/get-owner";
+
+export function warpStore() {
+  return getOwnerWithFallback().lookup("service:warp-store");
+}
+
+// Pure WarpDrive base. Ember/RestModel-API shims live in `rest-compat.js`.
+//
+// Subclass contract:
+//   static type             — schema type, e.g. "badge"
+//   static normalize        — rooted JSON → JSON:API document
+//   static builders         — { list(opts), one(id), save(record, data), delete(id) }
+export default class WarpRestModel {
+  static type = null;
+  static normalize = null;
+  static builders = null;
+
+  static findAll(opts) {
+    return requestMany(this, this.builders.list(opts));
+  }
+
+  static findById(id) {
+    return requestOne(this, this.builders.one(id));
+  }
+
+  // Synchronous ingest for preloaded payloads (PreloadStore, embedded sub-payloads).
+  static createFromJson(json) {
+    const store = warpStore();
+    const document = this.normalize(json);
+
+    if (Array.isArray(document.data)) {
+      const records = store.push(document);
+      return attachMeta(
+        records.map((r) => new this(r)),
+        document.meta
+      );
+    }
+    return new this(store.push(document));
+  }
+
+  #resource;
+
+  constructor(resource) {
+    this.#resource = resource;
+    this._applyExtraAttributes(resource?.id);
+  }
+
+  get __resource() {
+    return this.#resource;
+  }
+
+  // The resource this wrapper was constructed with, bypassing any subclass
+  // `__resource` override. Base constructors must use this: a subclass's own
+  // fields (and the getter that reads them) aren't initialized during `super()`.
+  get __ownResource() {
+    return this.#resource;
+  }
+
+  // Attributes the schema doesn't declare never reach the cache; re-attach the
+  // ones normalization retained for this identity. Called on construction and
+  // whenever the wrapper adopts a cached record — subclasses with their own
+  // ingest path (`TopicDetails`) call it after pushing.
+  _applyExtraAttributes(id) {
+    const { type } = this.constructor;
+    if (type == null || id == null) {
+      return;
+    }
+
+    const extras = extraAttributesFor(type, String(id));
+    if (extras) {
+      exposeExtraAttributes(this, extras);
+    }
+  }
+
+  // Swap `__resource` to the cached record for `id`.
+  _adoptResource(id) {
+    if (id == null) {
+      return;
+    }
+    const Klass = this.constructor;
+    const cached = warpStore().peekRecord({
+      type: Klass.type,
+      id: String(id),
+    });
+    if (cached && cached !== this.#resource) {
+      this.#resource = cached;
+    }
+    this._applyExtraAttributes(id);
+  }
+
+  updateFromJson(json) {
+    if (json == null) {
+      return this;
+    }
+    const Klass = this.constructor;
+    const document = Klass.normalize(json);
+    if (!document || Array.isArray(document.data)) {
+      return this;
+    }
+    warpStore().push(document);
+    this._adoptResource(document.data?.id);
+    return this;
+  }
+
+  async save(data) {
+    const Klass = this.constructor;
+    const store = warpStore();
+    const result = await store.request(Klass.builders.save(this, data));
+    this._adoptResource(result.content?.data?.id);
+    return this;
+  }
+
+  async destroy() {
+    const Klass = this.constructor;
+    const id = this.id;
+    if (id == null) {
+      return;
+    }
+    await warpStore().request(Klass.builders.delete(id));
+  }
+}
+
+// Attach document-level `meta` keys to the returned array so legacy callers
+// can read `result.grant_count` / `result.username` directly.
+export function attachMeta(records, meta) {
+  if (meta) {
+    Object.assign(records, meta);
+  }
+  return records;
+}
+
+export async function requestMany(Klass, request) {
+  const { content } = await warpStore().request(request);
+  return attachMeta(
+    (content?.data ?? []).map((r) => new Klass(r)),
+    content?.meta
+  );
+}
+
+export async function requestOne(Klass, request) {
+  const { content } = await warpStore().request(request);
+  return new Klass(content?.data);
+}
+
+// Install prototype getters/setters reading/writing `__resource` for each
+// schema field. Subclass-defined getters (image, url, ...) take precedence —
+// they're already on the prototype when this runs.
+export function defineFieldForwarders(Klass, schema) {
+  const proto = Klass.prototype;
+  const fieldKinds = new Map();
+  if (schema.identity?.name) {
+    fieldKinds.set(schema.identity.name, "@id");
+  }
+  for (const field of schema.fields ?? []) {
+    if (field.name && !fieldKinds.has(field.name)) {
+      fieldKinds.set(field.name, field.kind);
+    }
+  }
+  for (const [name, kind] of fieldKinds) {
+    // Skip names that resolve anywhere on the prototype chain — this is what
+    // keeps subclass getters and base methods (save, get, set, ...) from
+    // being shadowed by legacy-derived schema fields of the same name.
+    if (name in proto) {
+      continue;
+    }
+    const descriptor = {
+      configurable: true,
+      get() {
+        return this.__resource?.[name];
+      },
+    };
+    // JSON:API stores ids as strings; coerce numeric ones back so
+    // `badge.id === 1126` still works at Discourse call sites.
+    if (kind === "@id") {
+      descriptor.get = function () {
+        const raw = this.__resource?.[name];
+        if (typeof raw !== "string") {
+          return raw;
+        }
+        const num = Number(raw);
+        return Number.isFinite(num) && String(num) === raw ? num : raw;
+      };
+    }
+    // Relationships are read-only through the wrapper.
+    if (kind === "attribute") {
+      descriptor.set = function (value) {
+        if (this.__resource) {
+          this.__resource[name] = value;
+        }
+      };
+    }
+    Object.defineProperty(proto, name, descriptor);
+  }
+}
diff --git a/frontend/discourse/app/lib/grant-badge-utils.js b/frontend/discourse/app/lib/grant-badge-utils.js
index ec8cd8de1f7..5a24fdda53d 100644
--- a/frontend/discourse/app/lib/grant-badge-utils.js
+++ b/frontend/discourse/app/lib/grant-badge-utils.js
@@ -1,30 +1,29 @@
 import { convertIconClass } from "discourse/lib/icon-library";
 
 export function grantableBadges(allBadges, userBadges) {
-  const granted = userBadges.reduce((map, badge) => {
-    map[badge.get("badge_id")] = true;
-    return map;
-  }, {});
+  const granted = new Set(userBadges.map((ub) => ub.badge_id));
 
   return allBadges
-    .filter((badge) => {
-      return (
-        badge.get("enabled") &&
-        badge.get("manually_grantable") &&
-        (!granted[badge.get("id")] || badge.get("multiple_grant"))
-      );
-    })
-    .map((badge) => {
-      if (badge.get("icon")) {
-        badge.set("icon", convertIconClass(badge.icon));
-      }
-      return badge;
-    })
-    .sort((a, b) => a.get("name").localeCompare(b.get("name")));
+    .filter(
+      (badge) =>
+        badge.enabled &&
+        badge.manually_grantable &&
+        (!granted.has(badge.id) || badge.multiple_grant)
+    )
+    .sort((a, b) => a.name.localeCompare(b.name));
+}
+
+// `ComboBox` renders `item.icon` directly, so it needs the converted class.
+// Derived rather than assigned back: badge records are shared through the
+// store, and everything else converts at render time (`d-icon-or-image`).
+export function grantableBadgeOptions(badges) {
+  return badges.map((badge) => ({
+    id: badge.id,
+    name: badge.name,
+    icon: badge.icon ? convertIconClass(badge.icon) : null,
+  }));
 }
 
 export function isBadgeGrantable(badgeId, availableBadges) {
-  return !!(
-    availableBadges && availableBadges.some((b) => b.get("id") === badgeId)
-  );
+  return !!(availableBadges && availableBadges.some((b) => b.id === badgeId));
 }
diff --git a/frontend/discourse/app/lib/model-extensions.js b/frontend/discourse/app/lib/model-extensions.js
index 078d9e1fc45..ed60c0c4498 100644
--- a/frontend/discourse/app/lib/model-extensions.js
+++ b/frontend/discourse/app/lib/model-extensions.js
@@ -46,7 +46,9 @@ export function stampModelClass(klass, modelName) {
 }
 
 export function modelNameFor(instance) {
-  return instance?.constructor?.[MODEL_NAME];
+  // WarpDrive models carry their resolver name as `static type`; fall back to
+  // it so they resolve without depending on `stampModelClass` having run.
+  return instance?.constructor?.[MODEL_NAME] ?? instance?.constructor?.type;
 }
 
 // --- Fields (tracked data properties) ---
@@ -100,31 +102,42 @@ function defineTrackedArrayField(instance, name, value) {
   );
 }
 
-// Defines each registered field as a tracked property on the instance. Runs in
-// `RestModel`'s constructor, before the server payload, so a server value wins.
-export function applyRegisteredFields(instance) {
+function seedField(instance, name, value, type) {
+  if (type === "array") {
+    defineTrackedArrayField(instance, name, value);
+  } else if (type === "object") {
+    defineTrackedField(instance, name, trackedObject(value));
+  } else if (type === "set") {
+    defineTrackedField(instance, name, trackedSet(value));
+  } else {
+    defineTrackedField(instance, name, value);
+  }
+}
+
+// Defines each registered field as a tracked property on the instance.
+//
+// `RestModel` calls this in its constructor, before the server payload is
+// assigned, so a server value wins by overwriting the seeded default later.
+// WarpDrive models have their attributes in place at construction, so they pass
+// `resolveInitial(name) -> { value }` to make a caller/server value win up front
+// (returning a falsy result falls back to the registered default).
+export function applyRegisteredFields(instance, resolveInitial) {
   const modelFields = fields.get(modelNameFor(instance));
   if (!modelFields) {
     return;
   }
 
   for (const [name, { defaultValue, type }] of modelFields) {
+    const provided = resolveInitial?.(name);
     // Function defaults run per instance; a plain value is shared across
     // instances, so mutable defaults should use a function or a `type`.
-    const value =
-      typeof defaultValue === "function"
+    const value = provided
+      ? provided.value
+      : typeof defaultValue === "function"
         ? defaultValue.call(instance)
         : defaultValue;
 
-    if (type === "array") {
-      defineTrackedArrayField(instance, name, value);
-    } else if (type === "object") {
-      defineTrackedField(instance, name, trackedObject(value));
-    } else if (type === "set") {
-      defineTrackedField(instance, name, trackedSet(value));
-    } else {
-      defineTrackedField(instance, name, value);
-    }
+    seedField(instance, name, value, type);
   }
 }
 
diff --git a/frontend/discourse/app/models/archetype.js b/frontend/discourse/app/models/archetype.js
index 69cae55a138..dfb2568e378 100644
--- a/frontend/discourse/app/models/archetype.js
+++ b/frontend/discourse/app/models/archetype.js
@@ -1,20 +1,22 @@
-import { computed } from "@ember/object";
+import RestCompatModel from "discourse/data/rest-compat";
+import { ArchetypeSchema } from "discourse/data/schemas/archetype";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 import { deepEqual } from "discourse/lib/object";
-import RestModel from "discourse/models/rest";
 
-export default class Archetype extends RestModel {
-  @computed("options.length")
+export default class Archetype extends RestCompatModel {
+  static type = "archetype";
+
   get hasOptions() {
     return this.options?.length > 0;
   }
 
-  @computed("id", "site.default_archetype")
   get isDefault() {
     return deepEqual(this.id, this.site?.default_archetype);
   }
 
-  @computed("isDefault")
   get notDefault() {
     return !this.isDefault;
   }
 }
+
+defineFieldForwarders(Archetype, ArchetypeSchema);
diff --git a/frontend/discourse/app/models/badge-grouping.js b/frontend/discourse/app/models/badge-grouping.js
index 0a1f39f7945..8bc2495ddcb 100644
--- a/frontend/discourse/app/models/badge-grouping.js
+++ b/frontend/discourse/app/models/badge-grouping.js
@@ -2,6 +2,11 @@ import { computed } from "@ember/object";
 import RestModel from "discourse/models/rest";
 import { i18n } from "discourse-i18n";
 
+export function badgeGroupingDisplayName(name) {
+  const i18nKey = `badges.badge_grouping.${name.toLowerCase().replace(/\s/g, "_")}.name`;
+  return i18n(i18nKey, { defaultValue: name });
+}
+
 export default class BadgeGrouping extends RestModel {
   @computed("name")
   get i18nNameKey() {
@@ -10,7 +15,6 @@ export default class BadgeGrouping extends RestModel {
 
   @computed("name")
   get displayName() {
-    const i18nKey = `badges.badge_grouping.${this.i18nNameKey}.name`;
-    return i18n(i18nKey, { defaultValue: this.name });
+    return badgeGroupingDisplayName(this.name);
   }
 }
diff --git a/frontend/discourse/app/models/badge.js b/frontend/discourse/app/models/badge.js
index 6337f4ce9ed..e238d656a46 100644
--- a/frontend/discourse/app/models/badge.js
+++ b/frontend/discourse/app/models/badge.js
@@ -1,131 +1,42 @@
-import EmberObject, { computed, set } from "@ember/object";
-import { Promise } from "rsvp";
-import { ajax } from "discourse/lib/ajax";
+import {
+  deleteBadge,
+  findBadge,
+  findBadges,
+  saveBadge,
+} from "discourse/data/builders/badges";
+import { normalizeBadgesPayload } from "discourse/data/normalize";
+import RestCompatModel from "discourse/data/rest-compat";
+import { BadgeSchema } from "discourse/data/schemas/badge";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 import getURL from "discourse/lib/get-url";
-import BadgeGrouping from "discourse/models/badge-grouping";
-import RestModel from "discourse/models/rest";
 
-export default class Badge extends RestModel {
-  static createFromJson(json) {
-    // Create BadgeType objects.
-    const badgeTypes = {};
-    if ("badge_types" in json) {
-      json.badge_types.forEach(
-        (badgeTypeJson) =>
-          (badgeTypes[badgeTypeJson.id] = EmberObject.create(badgeTypeJson))
-      );
-    }
+export default class Badge extends RestCompatModel {
+  static type = "badge";
+  static normalize = normalizeBadgesPayload;
+  static builders = {
+    list: findBadges,
+    one: findBadge,
+    save: saveBadge,
+    delete: deleteBadge,
+  };
 
-    const badgeGroupings = {};
-    if ("badge_groupings" in json) {
-      json.badge_groupings.forEach(
-        (badgeGroupingJson) =>
-          (badgeGroupings[badgeGroupingJson.id] =
-            BadgeGrouping.create(badgeGroupingJson))
-      );
-    }
-
-    // Create Badge objects.
-    let badges = [];
-    if ("badge" in json) {
-      badges = [json.badge];
-    } else if (json.badges) {
-      badges = json.badges;
-    }
-    badges = badges.map((badgeJson) => {
-      const badge = Badge.create(badgeJson);
-      badge.setProperties({
-        badge_type: badgeTypes[badge.badge_type_id],
-        badge_grouping: badgeGroupings[badge.badge_grouping_id],
-      });
-      return badge;
-    });
-
-    if ("badge" in json) {
-      return badges[0];
-    } else {
-      return badges;
-    }
-  }
-
-  static findAll(opts) {
-    let listable = "";
-    if (opts && opts.onlyListable) {
-      listable = "?only_listable=true";
-    }
-
-    return ajax(`/badges.json${listable}`, { data: opts }).then((badgesJson) =>
-      Badge.createFromJson(badgesJson)
-    );
-  }
-
-  static findById(id) {
-    return ajax(`/badges/${id}`).then((badgeJson) =>
-      Badge.createFromJson(badgeJson)
-    );
-  }
-
-  @computed("id")
-  get newBadge() {
-    return this.id == null;
-  }
-
-  @computed("image_url")
+  // The `icon-or-image` helper reads `badge.image`.
   get image() {
     return this.image_url;
   }
 
-  set image(value) {
-    set(this, "image_url", value);
-  }
-
-  @computed
   get url() {
     return getURL(`/badges/${this.id}/${this.slug}`);
   }
 
-  updateFromJson(json) {
-    if (json.badge) {
-      Object.keys(json.badge).forEach((key) => this.set(key, json.badge[key]));
-    }
-    if (json.badge_types) {
-      json.badge_types.forEach((badgeType) => {
-        if (badgeType.id === this.badge_type_id) {
-          this.set("badge_type", Object.create(badgeType));
-        }
-      });
-    }
+  get newBadge() {
+    return this.id == null;
   }
 
-  @computed("badge_type.name")
   get badgeTypeClassName() {
     const type = this.badge_type?.name || "";
     return `badge-type-${type.toLowerCase()}`;
   }
-
-  save(data) {
-    let url = "/admin/badges",
-      type = "POST";
-
-    if (this.id) {
-      // We are updating an existing badge.
-      url += `/${this.id}`;
-      type = "PUT";
-    }
-
-    return ajax(url, { type, data }).then((json) => {
-      this.updateFromJson(json);
-      return this;
-    });
-  }
-
-  destroy() {
-    if (this.newBadge) {
-      return Promise.resolve();
-    }
-
-    return ajax(`/admin/badges/${this.id}`, {
-      type: "DELETE",
-    });
-  }
 }
+
+defineFieldForwarders(Badge, BadgeSchema);
diff --git a/frontend/discourse/app/models/bookmark.js b/frontend/discourse/app/models/bookmark.js
index 307eba655b6..4422d7d6dbb 100644
--- a/frontend/discourse/app/models/bookmark.js
+++ b/frontend/discourse/app/models/bookmark.js
@@ -1,13 +1,22 @@
-import { computed } from "@ember/object";
 import { capitalize } from "@ember/string";
 import { isEmpty } from "@ember/utils";
 import { Promise } from "rsvp";
-import { ajax } from "discourse/lib/ajax";
+import {
+  bulkBookmarkOperation,
+  deleteBookmark,
+  togglePinBookmark,
+} from "discourse/data/builders/bookmarks";
+import RestCompatModel from "discourse/data/rest-compat";
+import { BookmarkSchema } from "discourse/data/schemas/bookmark";
+import {
+  defineFieldForwarders,
+  warpStore,
+} from "discourse/data/warp-rest-model";
 import { formattedReminderTime } from "discourse/lib/bookmark";
 import { longDate } from "discourse/lib/formatter";
+import { getOwnerWithFallback } from "discourse/lib/get-owner";
 import getURL from "discourse/lib/get-url";
 import { applyModelTransformations } from "discourse/lib/model-transformers";
-import RestModel from "discourse/models/rest";
 import Topic from "discourse/models/topic";
 import User from "discourse/models/user";
 import { i18n } from "discourse-i18n";
@@ -24,12 +33,22 @@ export const NO_REMINDER_ICON = "bookmark";
 export const NOT_BOOKMARKED = "far-bookmark";
 export const WITH_REMINDER_ICON = "discourse-bookmark-clock";
 
-export default class Bookmark extends RestModel {
-  static create(args) {
-    args = args || {};
-    args.currentUser = args.currentUser || User.current();
-    args.user = User.create(args.user);
-    return super.create(args);
+export default class Bookmark extends RestCompatModel {
+  static type = "bookmark";
+  static builders = { delete: deleteBookmark };
+
+  // `user` is wrapped as a User instance (legacy parity); `currentUser` is
+  // stashed on the wrapper as an own property (survives `_adoptResource` and
+  // isn't part of the schema).
+  static create(args = {}) {
+    if (args instanceof Bookmark) {
+      return args;
+    }
+
+    const { user, currentUser, ...rest } = args;
+    const wrapper = super.create({ ...rest, user: User.create(user) });
+    wrapper.currentUser = currentUser || User.current();
+    return wrapper;
   }
 
   static createFor(user, bookmarkableType, bookmarkableId) {
@@ -42,41 +61,30 @@ export default class Bookmark extends RestModel {
   }
 
   static bulkOperation(bookmarks, operation) {
-    const data = {
-      bookmark_ids: bookmarks.map((item) => item.id),
-      operation,
-    };
-
-    return ajax("/bookmarks/bulk", {
-      type: "PUT",
-      data,
-    });
+    return warpStore().request(
+      bulkBookmarkOperation(
+        bookmarks.map((b) => b.id),
+        operation
+      )
+    );
   }
 
   static async applyTransformations(bookmarks) {
     await applyModelTransformations("bookmark", bookmarks);
   }
 
-  @computed("id")
+  #topicForList;
+
+  #siteSettings;
+
   get newBookmark() {
     return this.id == null;
   }
 
-  @computed
   get url() {
     return getURL(`/bookmarks/${this.id}`);
   }
 
-  destroy() {
-    if (this.newBookmark) {
-      return Promise.resolve();
-    }
-
-    return ajax(this.url, {
-      type: "DELETE",
-    });
-  }
-
   attachedTo() {
     return {
       target: this.bookmarkable_type.toLowerCase(),
@@ -88,17 +96,13 @@ export default class Bookmark extends RestModel {
     if (this.newBookmark) {
       return Promise.resolve();
     }
-
-    return ajax(this.url + "/toggle_pin", {
-      type: "PUT",
-    });
+    return warpStore().request(togglePinBookmark(this.id));
   }
 
   pinAction() {
     return this.pinned ? "unpin" : "pin";
   }
 
-  @computed("topic_id", "highest_post_number", "bookmarkable_url")
   get lastPostUrl() {
     return this.topic_id
       ? this.urlForPostNumber(this.highest_post_number)
@@ -113,12 +117,10 @@ export default class Bookmark extends RestModel {
     return url;
   }
 
-  @computed("bumped_at", "createdAt")
   get bumpedAt() {
     return this.bumped_at ? new Date(this.bumped_at) : this.createdAt;
   }
 
-  @computed("bumpedAt", "createdAt")
   get bumpedAtTitle() {
     const BUMPED_FORMAT = "YYYY-MM-DDTHH:mm:ss";
     if (moment(this.bumpedAt).isValid() && moment(this.createdAt).isValid()) {
@@ -133,14 +135,14 @@ export default class Bookmark extends RestModel {
     }
   }
 
-  @computed("name", "reminder_at")
+  get timezone() {
+    return this.currentUser?.user_option?.timezone || moment.tz.guess();
+  }
+
   get reminderTitle() {
     if (!isEmpty(this.reminder_at)) {
       return i18n("bookmarks.created_with_reminder_generic", {
-        date: formattedReminderTime(
-          this.reminder_at,
-          this.currentUser?.user_option?.timezone || moment.tz.guess()
-        ),
+        date: formattedReminderTime(this.reminder_at, this.timezone),
         name: this.name || "",
       });
     }
@@ -150,73 +152,59 @@ export default class Bookmark extends RestModel {
     });
   }
 
-  @computed("created_at")
   get createdAt() {
     return new Date(this.created_at);
   }
 
-  @computed("tags")
+  // Read per row on the bookmark list — cache the service lookup.
   get visibleListTags() {
-    if (!this.tags || !this.siteSettings.suppress_overlapping_tags_in_list) {
-      return this.tags;
+    const tags = this.tags;
+    this.#siteSettings ??= getOwnerWithFallback().lookup(
+      "service:site-settings"
+    );
+    if (!tags || !this.#siteSettings.suppress_overlapping_tags_in_list) {
+      return tags;
     }
 
-    const title = this.title;
-    const newTags = [];
-
-    this.tags.forEach(function (tag) {
-      if (!title.toLowerCase().includes(tag)) {
-        newTags.push(tag);
-      }
-    });
-
-    return newTags;
+    const title = this.title.toLowerCase();
+    return tags.filter((tag) => !title.includes(tag));
   }
 
-  @computed("category_id")
   get category() {
     return Category.findById(this.category_id);
   }
 
-  @computed("reminder_at", "currentUser")
   get formattedReminder() {
-    return capitalize(
-      formattedReminderTime(
-        this.reminder_at,
-        this.currentUser?.user_option?.timezone || moment.tz.guess()
-      )
-    );
+    return capitalize(formattedReminderTime(this.reminder_at, this.timezone));
   }
 
-  @computed("reminder_at")
   get reminderAtExpired() {
     return moment(this.reminder_at) < moment();
   }
 
-  @computed()
+  // For topic-level bookmarks, no linked post number — let the topic-link
+  // helper jump to the last unread post by default.
+  //
+  // Built once: read from a list row, where a fresh `Topic` per read would fire
+  // `init` callbacks on every rerender and hand out a new identity each time.
   get topicForList() {
-    // for topic level bookmarks we want to jump to the last unread post URL,
-    // which the topic-link helper does by default if no linked post number is
-    // provided
-    const linkedPostNumber =
-      this.bookmarkable_type === "Topic" ? null : this.linked_post_number;
-
-    return Topic.create({
+    return (this.#topicForList ??= Topic.create({
       id: this.topic_id,
       fancy_title: this.fancy_title,
-      linked_post_number: linkedPostNumber,
+      linked_post_number:
+        this.bookmarkable_type === "Topic" ? null : this.linked_post_number,
       last_read_post_number: this.last_read_post_number,
       highest_post_number: this.highest_post_number,
-    });
+    }));
   }
 
-  @computed("bookmarkable_type")
   get bookmarkableTopicAlike() {
     return ["Topic", "Post"].includes(this.bookmarkable_type);
   }
 
-  @computed("reminder_at", "name")
   get hasMetadata() {
     return this.reminder_at || this.name;
   }
 }
+
+defineFieldForwarders(Bookmark, BookmarkSchema);
diff --git a/frontend/discourse/app/models/tag-group.js b/frontend/discourse/app/models/tag-group.js
index a4b34b4479a..be30e9fa13f 100644
--- a/frontend/discourse/app/models/tag-group.js
+++ b/frontend/discourse/app/models/tag-group.js
@@ -1,9 +1,11 @@
-import { computed } from "@ember/object";
+import RestCompatModel from "discourse/data/rest-compat";
+import { TagGroupSchema } from "discourse/data/schemas/tag-group";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 import PermissionType from "discourse/models/permission-type";
-import RestModel from "discourse/models/rest";
 
-export default class TagGroup extends RestModel {
-  @computed("permissions")
+export default class TagGroup extends RestCompatModel {
+  static type = "tag-group";
+
   get permissionName() {
     if (!this.permissions) {
       return "public";
@@ -18,3 +20,5 @@ export default class TagGroup extends RestModel {
     }
   }
 }
+
+defineFieldForwarders(TagGroup, TagGroupSchema);
diff --git a/frontend/discourse/app/models/tag-info.js b/frontend/discourse/app/models/tag-info.js
index fdb09390af9..3b3009035f0 100644
--- a/frontend/discourse/app/models/tag-info.js
+++ b/frontend/discourse/app/models/tag-info.js
@@ -1,18 +1,9 @@
-import { tracked } from "@glimmer/tracking";
-import { autoTrackedArray } from "discourse/lib/tracked-tools";
-import RestModel from "discourse/models/rest";
+import RestCompatModel from "discourse/data/rest-compat";
+import { TagInfoSchema } from "discourse/data/schemas/tag-info";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 
-export default class TagInfo extends RestModel {
-  @tracked category_restricted;
-  @tracked description;
-  @tracked id;
-  @tracked name;
-  @tracked slug;
-  @tracked staff;
-  @tracked topic_count;
-
-  @autoTrackedArray categories;
-  @autoTrackedArray localizations;
-  @autoTrackedArray synonyms;
-  @autoTrackedArray tag_group_names;
+export default class TagInfo extends RestCompatModel {
+  static type = "tag-info";
 }
+
+defineFieldForwarders(TagInfo, TagInfoSchema);
diff --git a/frontend/discourse/app/models/tag-notification.js b/frontend/discourse/app/models/tag-notification.js
index 62f48c8cb6b..03d2a13cfd1 100644
--- a/frontend/discourse/app/models/tag-notification.js
+++ b/frontend/discourse/app/models/tag-notification.js
@@ -1,5 +1,10 @@
-import RestModel from "discourse/models/rest";
+import RestCompatModel from "discourse/data/rest-compat";
+import { TagNotificationSchema } from "discourse/data/schemas/tag-notification";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 
-export default class TagNotification extends RestModel {
+export default class TagNotification extends RestCompatModel {
+  static type = "tag-notification";
   primaryKey = "name";
 }
+
+defineFieldForwarders(TagNotification, TagNotificationSchema);
diff --git a/frontend/discourse/app/models/tag-settings.js b/frontend/discourse/app/models/tag-settings.js
index e605088550f..534813043c0 100644
--- a/frontend/discourse/app/models/tag-settings.js
+++ b/frontend/discourse/app/models/tag-settings.js
@@ -1,3 +1,9 @@
-import RestModel from "discourse/models/rest";
+import RestCompatModel from "discourse/data/rest-compat";
+import { TagSettingsSchema } from "discourse/data/schemas/tag-settings";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 
-export default class TagSettings extends RestModel {}
+export default class TagSettings extends RestCompatModel {
+  static type = "tag-settings";
+}
+
+defineFieldForwarders(TagSettings, TagSettingsSchema);
diff --git a/frontend/discourse/app/models/tag.js b/frontend/discourse/app/models/tag.js
index 2ea59bb2fdf..2623dd38224 100644
--- a/frontend/discourse/app/models/tag.js
+++ b/frontend/discourse/app/models/tag.js
@@ -1,14 +1,15 @@
-import { computed } from "@ember/object";
+import RestCompatModel from "discourse/data/rest-compat";
+import { TagSchema } from "discourse/data/schemas/tag";
+import { defineFieldForwarders } from "discourse/data/warp-rest-model";
 import getURL from "discourse/lib/get-url";
-import RestModel from "discourse/models/rest";
 
-export default class Tag extends RestModel {
-  @computed("pm_only")
+export default class Tag extends RestCompatModel {
+  static type = "tag";
+
   get pmOnly() {
     return this.pm_only;
   }
 
-  @computed("slug", "id")
   get url() {
     if (this.id) {
       const slugForUrl = this.slug || `${this.id}-tag`;
@@ -18,19 +19,18 @@ export default class Tag extends RestModel {
     return getURL(`/tag/${this.name.replaceAll(".", "%2E")}`);
   }
 
-  @computed("count", "pm_count")
   get totalCount() {
     return this.pm_count ? this.count + this.pm_count : this.count;
   }
 
-  @computed("id", "name")
   get searchContext() {
     return {
       type: "tag",
       id: this.id,
-      /** @type Tag */
-      tag: this,
+      tag: /** @type {Tag} */ (this),
       name: this.name,
     };
   }
 }
+
+defineFieldForwarders(Tag, TagSchema);
diff --git a/frontend/discourse/app/models/topic-details.js b/frontend/discourse/app/models/topic-details.js
index bf1b98ae2b1..772c5c9dd6a 100644
--- a/frontend/discourse/app/models/topic-details.js
+++ b/frontend/discourse/app/models/topic-details.js
@@ -1,90 +1,143 @@
 import { tracked } from "@glimmer/tracking";
 import EmberObject from "@ember/object";
-import { service } from "@ember/service";
-import { ajax } from "discourse/lib/ajax";
-import { removeValueFromArray } from "discourse/lib/array-tools";
-import { autoTrackedArray } from "discourse/lib/tracked-tools";
-import RestModel from "discourse/models/rest";
+import {
+  removeAllowedTopicGroup,
+  removeAllowedTopicUser,
+  updateTopicNotificationLevel,
+} from "discourse/data/builders/topic-details";
+import { normalizeTopicDetailsPayload } from "discourse/data/normalize";
+import RestCompatModel from "discourse/data/rest-compat";
+import { TopicDetailsSchema } from "discourse/data/schemas/topic-details";
+import {
+  defineFieldForwarders,
+  warpStore,
+} from "discourse/data/warp-rest-model";
+import User from "discourse/models/user";
 
-/**
-  A model representing a Topic's details that aren't always present, such as a list of participants.
-  When showing topics in lists and such this information should not be required.
-**/
+export default class TopicDetails extends RestCompatModel {
+  static type = "topic-details";
 
-export default class TopicDetails extends RestModel {
-  @service store;
+  // `store.createRecord("topicDetails", { id, topic, ...attrs })` entry point.
+  // Extras (e.g. tests doing `topic.details = { allowed_users: [...] }`) land
+  // in `#draft` until `updateFromJson` populates the cache record.
+  static create({ id, topic, ...rest } = {}) {
+    const td = new this(id);
+    if (topic !== undefined) {
+      td.topic = topic;
+    }
+    if (Object.keys(rest).length > 0) {
+      td.#draft = rest;
+    }
+    return td;
+  }
 
-  @tracked can_delete;
-  @tracked can_edit_staff_notes;
-  @tracked can_permanently_delete;
-  @tracked can_publish_page;
-  @tracked can_split_merge_topic;
-  @tracked created_by;
-  @tracked notification_level;
-  @autoTrackedArray allowed_groups;
-  @autoTrackedArray allowed_users;
+  @tracked loaded = false;
+  topic = null;
 
-  loaded = false;
+  #topicId;
+  #cachedRecord;
+  #draft = {};
 
+  constructor(topicId) {
+    super();
+    this.#topicId = topicId == null ? null : String(topicId);
+  }
+
+  // Topic's `_details` field initializer runs before Topic.id is assigned, so
+  // back-fill lazily from `this.topic.id` on first access.
+  #effectiveTopicId() {
+    if (this.#topicId == null && this.topic?.id != null) {
+      this.#topicId = String(this.topic.id);
+    }
+    return this.#topicId;
+  }
+
+  // `#topicId in this` is only true once `super()` has returned and our own
+  // fields and private methods are installed. The base constructor fires plugin
+  // `init` callbacks, which can reach `id` / `__resource` before that — and
+  // touching anything private that early throws. The check has to be inline:
+  // hiding it behind a private helper would trip the same trap.
+  get id() {
+    return #topicId in this ? this.#effectiveTopicId() : null;
+  }
+
+  // Falls back to `#draft` so attrs set via `create({...})` (or assigned
+  // before `updateFromJson`) are readable/writable. The cached record is
+  // memoized (identity is stable per type + id): this getter backs every field
+  // forwarder, and topic templates read those on every render.
+  get __resource() {
+    // See `id` — nothing private is reachable until `super()` has returned.
+    if (!(#topicId in this)) {
+      return undefined;
+    }
+    if (this.#cachedRecord) {
+      return this.#cachedRecord;
+    }
+    const id = this.#effectiveTopicId();
+    if (id != null) {
+      const cached = warpStore().peekRecord({
+        type: "topic-details",
+        id,
+      });
+      if (cached) {
+        return (this.#cachedRecord = cached);
+      }
+    }
+    return this.#draft;
+  }
+
+  // Wraps user/participant sideloads to match legacy RestModel behavior so
+  // `instanceof User` and EmberObject methods keep working.
   updateFromJson(details) {
-    const topic = this.topic;
-
+    const id = this.#effectiveTopicId();
+    if (id == null || !details) {
+      return;
+    }
+    const wrapped = { ...details };
     if (details.allowed_users) {
-      details.allowed_users = details.allowed_users.map((u) =>
-        this.store.createRecord("user", u)
+      wrapped.allowed_users = details.allowed_users.map((u) => User.create(u));
+    }
+    if (details.participants) {
+      const topic = this.topic;
+      wrapped.participants = details.participants.map((p) =>
+        EmberObject.create({ ...p, topic })
       );
     }
-
-    if (details.participants) {
-      details.participants = details.participants.map((p) => {
-        p.topic = topic;
-        return EmberObject.create(p);
-      });
-    }
-
-    this.setProperties(details);
-    this.set("loaded", true);
+    const store = warpStore();
+    store.push(normalizeTopicDetailsPayload({ topicId: id, details: wrapped }));
+    this._applyExtraAttributes(id);
+    this.loaded = true;
   }
 
   updateNotifications(level) {
-    return ajax(`/t/${this.get("topic.id")}/notifications`, {
-      type: "POST",
-      data: { notification_level: level },
-    }).then(() => {
-      this.setProperties({
-        notification_level: level,
-        notifications_reason_id: null,
-      });
+    const store = warpStore();
+    const id = this.#effectiveTopicId();
+    return store.request(updateTopicNotificationLevel(id, level)).then(() => {
+      this.notification_level = level;
+      this.notifications_reason_id = null;
     });
   }
 
   async removeAllowedGroup(group) {
-    const groups = this.allowed_groups;
-    const name = group.name;
-
-    await ajax(`/t/${this.get("topic.id")}/remove-allowed-group`, {
-      type: "PUT",
-      data: { name },
-    });
-
-    removeValueFromArray(
-      groups,
-      groups.find((item) => item.name === name)
+    const store = warpStore();
+    await store.request(
+      removeAllowedTopicGroup(this.#effectiveTopicId(), group.name)
+    );
+    this.allowed_groups = this.allowed_groups.filter(
+      (g) => g.name !== group.name
     );
   }
 
   async removeAllowedUser(user) {
-    const users = this.allowed_users;
-    const username = user.get("username");
-
-    await ajax(`/t/${this.get("topic.id")}/remove-allowed-user`, {
-      type: "PUT",
-      data: { username },
-    });
-
-    removeValueFromArray(
-      users,
-      users.find((item) => item.username === username)
+    const username = user.username ?? user.get?.("username");
+    const store = warpStore();
+    await store.request(
+      removeAllowedTopicUser(this.#effectiveTopicId(), username)
+    );
+    this.allowed_users = this.allowed_users.filter(
+      (u) => u.username !== username
     );
   }
 }
+
+defineFieldForwarders(TopicDetails, TopicDetailsSchema);
diff --git a/frontend/discourse/app/models/user-badge.js b/frontend/discourse/app/models/user-badge.js
index 13c1eaba8cc..d494c777aa4 100644
--- a/frontend/discourse/app/models/user-badge.js
+++ b/frontend/discourse/app/models/user-badge.js
@@ -1,168 +1,113 @@
-import EmberObject, { computed } from "@ember/object";
-import { Promise } from "rsvp";
+import {
+  findUserBadgesByBadgeId,
+  findUserBadgesByUsername,
+  grantUserBadge,
+  toggleFavoriteUserBadge,
+} from "discourse/data/builders/user-badges";
+import { normalizeUserBadgesPayload } from "discourse/data/normalize";
+import RestCompatModel from "discourse/data/rest-compat";
+import { UserBadgeSchema } from "discourse/data/schemas/user-badge";
+import {
+  defineFieldForwarders,
+  requestMany,
+  requestOne,
+  warpStore,
+} from "discourse/data/warp-rest-model";
 import { ajax } from "discourse/lib/ajax";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import Badge from "discourse/models/badge";
-import Topic from "discourse/models/topic";
-import User from "discourse/models/user";
 
-export default class UserBadge extends EmberObject {
-  static createFromJson(json) {
-    // Create User objects.
-    if (json.users === undefined) {
-      json.users = [];
-    }
-    let users = {};
-    json.users.forEach(function (userJson) {
-      users[userJson.id] = User.create(userJson);
-    });
+export default class UserBadge extends RestCompatModel {
+  static type = "user-badge";
+  static normalize = normalizeUserBadgesPayload;
 
-    json.granted_bies = json.granted_bies ?? [];
-    json.granted_bies.forEach(function (userJson) {
-      users[userJson.id] = User.create(userJson);
-    });
-
-    // Create Topic objects.
-    if (json.topics === undefined) {
-      json.topics = [];
-    }
-    let topics = {};
-    json.topics.forEach(function (topicJson) {
-      topics[topicJson.id] = Topic.create(topicJson);
-    });
-
-    // Create the badges.
-    if (json.badges === undefined) {
-      json.badges = [];
-    }
-    let badges = {};
-    Badge.createFromJson(json).forEach(function (badge) {
-      badges[badge.get("id")] = badge;
-    });
-
-    // Create UserBadge object(s).
-    let userBadges;
-    if ("user_badge" in json) {
-      userBadges = [json.user_badge];
-    } else {
-      userBadges =
-        (json.user_badge_info && json.user_badge_info.user_badges) ||
-        json.user_badges;
-    }
-
-    userBadges = userBadges.map(function (userBadgeJson) {
-      let userBadge = UserBadge.create(userBadgeJson);
-
-      let grantedAtDate = Date.parse(userBadge.get("granted_at"));
-      userBadge.set("grantedAt", grantedAtDate);
-
-      userBadge.set("badge", badges[userBadge.get("badge_id")]);
-      if (userBadge.get("user_id")) {
-        userBadge.set("user", users[userBadge.get("user_id")]);
-      }
-      if (userBadge.get("granted_by_id")) {
-        userBadge.set("granted_by", users[userBadge.get("granted_by_id")]);
-      }
-      if (userBadge.get("topic_id")) {
-        userBadge.set("topic", topics[userBadge.get("topic_id")]);
-      }
-      return userBadge;
-    });
-
-    if ("user_badge" in json) {
-      return userBadges[0];
-    } else {
-      if (json.user_badge_info) {
-        userBadges.grant_count = json.user_badge_info.grant_count;
-        userBadges.username = json.user_badge_info.username;
-      }
-      return userBadges;
-    }
-  }
-
-  /**
-    Find all badges for a given username.
-
-    @method findByUsername
-    @param {String} username
-    @param {Object} options
-    @returns {Promise} a promise that resolves to an array of `UserBadge`.
-  **/
-  static findByUsername(username, options) {
+  // Async so callers can `.then` even on the no-username short circuit
+  // (`badges.show` passes a null username for anonymous visitors).
+  static async findByUsername(username, options = {}) {
     if (!username) {
-      return Promise.resolve([]);
+      return [];
     }
-    let url = "/user-badges/" + username + ".json";
-    if (options && options.grouped) {
-      url += "?grouped=true";
-    }
-    return ajax(url).then(function (json) {
-      return UserBadge.createFromJson(json);
-    });
+    return requestMany(this, findUserBadgesByUsername(username, options));
   }
 
-  /**
-    Find all badge grants for a given badge ID.
-
-    @method findById
-    @param {String} badgeId
-    @returns {Promise} a promise that resolves to an array of `UserBadge`.
-  **/
-  static findByBadgeId(badgeId, options) {
-    if (!options) {
-      options = {};
-    }
-    options.badge_id = badgeId;
-
-    return ajax("/user_badges.json", {
-      data: options,
-    }).then(function (json) {
-      return UserBadge.createFromJson(json);
-    });
+  static findByBadgeId(badgeId, options = {}) {
+    return requestMany(this, findUserBadgesByBadgeId(badgeId, options));
   }
 
-  /**
-    Grant the badge having id `badgeId` to the user identified by `username`.
-
-    @method grant
-    @param {Integer} badgeId id of the badge to be granted.
-    @param {String} username username of the user to be granted the badge.
-    @returns {Promise} a promise that resolves to an instance of `UserBadge`.
-  **/
   static grant(badgeId, username, reason) {
-    return ajax("/user_badges", {
-      type: "POST",
-      data: {
-        username,
-        badge_id: badgeId,
-        reason,
-      },
-    }).then(function (json) {
-      return UserBadge.createFromJson(json);
+    return requestOne(this, grantUserBadge(badgeId, username, reason));
+  }
+
+  #badge;
+  #badgeResource;
+
+  // Wraps the cached resource in a `Badge` so callers can read its computed
+  // getters (`.url`, `.badgeTypeClassName`, ...). Memoized against that
+  // resource — a fresh instance per read would fire `init` callbacks and break
+  // identity — while the unconditional read keeps its tracked tag consumed.
+  get badge() {
+    const resource = this.__resource?.badge;
+    if (resource !== this.#badgeResource) {
+      this.#badgeResource = resource;
+      this.#badge = resource ? new Badge(resource) : undefined;
+    }
+    return this.#badge;
+  }
+
+  // Getter: null → undefined (test contract).
+  get granted_by() {
+    return this.__resource?.granted_by ?? undefined;
+  }
+
+  // Setter: shadows on the wrapper so admin's read-then-write `groupedBadges`
+  // doesn't trip Glimmer.
+  set granted_by(value) {
+    Object.defineProperty(this, "granted_by", {
+      value,
+      writable: true,
+      configurable: true,
+      enumerable: true,
     });
   }
 
-  @computed
+  get grantedAt() {
+    return this.granted_at ? Date.parse(this.granted_at) : null;
+  }
+
   get postUrl() {
     if (this.topic_title) {
-      return "/t/-/" + this.topic_id + "/" + this.post_number;
+      return `/t/-/${this.topic_id}/${this.post_number}`;
     }
-  } // avoid the extra bindings for now
-
-  revoke() {
-    return ajax("/user_badges/" + this.id, {
-      type: "DELETE",
-    });
   }
 
-  favorite() {
-    this.toggleProperty("is_favorite");
-    return ajax(`/user_badges/${this.id}/toggle_favorite`, {
-      type: "PUT",
-    }).catch((e) => {
-      // something went wrong, switch the UI back:
-      this.toggleProperty("is_favorite");
-      popupAjaxError(e);
+  // Direct ajax so admin callers can read the response body.
+  revoke() {
+    return ajax(`/user_badges/${this.id}`, { type: "DELETE" });
+  }
+
+  async favorite() {
+    const store = warpStore();
+    const previous = this.is_favorite;
+    const partial = (value) => ({
+      data: {
+        type: "user-badge",
+        id: String(this.id),
+        attributes: { is_favorite: value },
+      },
     });
+
+    // Optimistic flip. `_adoptResource` swaps a draft wrapper to the now-
+    // cached record so the new value is visible.
+    store.push(partial(!previous));
+    this._adoptResource(this.id);
+
+    try {
+      await store.request(toggleFavoriteUserBadge(this.id));
+    } catch (e) {
+      store.push(partial(previous));
+      popupAjaxError(e);
+    }
   }
 }
+
+defineFieldForwarders(UserBadge, UserBadgeSchema);
diff --git a/frontend/discourse/app/routes/topic/from-params.js b/frontend/discourse/app/routes/topic/from-params.js
index c03091019a0..9a9ca17cd8e 100644
--- a/frontend/discourse/app/routes/topic/from-params.js
+++ b/frontend/discourse/app/routes/topic/from-params.js
@@ -152,23 +152,24 @@ export default class TopicFromParams extends DiscourseRoute {
     const topic = this.modelFor("topic");
     const postStream = topic.postStream;
 
-    // TODO we are seeing errors where closest post is null and this is exploding
-    // we need better handling and logging for this condition.
-
     // there are no closestPost for hidden topics
     if (topic.view_hidden) {
       return;
     }
 
-    // The post we requested might not exist. Let's find the closest post
+    // The post we requested might not exist. Let's find the closest post —
+    // a topic with no posts at all has none, so everything keyed off a post
+    // is skipped below while the route itself still sets up.
     const closestPost = postStream.closestPostForPostNumber(
       params.nearPost || 1
     );
-    const closest = closestPost.post_number;
+    const closest = closestPost?.post_number;
 
     topicController.setProperties({
       "model.currentPost": closest,
-      enteredIndex: topic.postStream.progressIndexOfPost(closestPost),
+      enteredIndex: closestPost
+        ? topic.postStream.progressIndexOfPost(closestPost)
+        : undefined,
       enteredAt: Date.now().toString(),
       userLastReadPostNumber: topic.last_read_post_number,
       highestPostNumber: topic.highest_post_number,
@@ -181,23 +182,25 @@ export default class TopicFromParams extends DiscourseRoute {
       this.screenTrack.start(topic.id, topicController);
     }
 
-    // Highlight our post after the next render
-    schedule("afterRender", () =>
-      this.appEvents.trigger("post:highlight", closest)
-    );
+    if (closestPost) {
+      // Highlight our post after the next render
+      schedule("afterRender", () =>
+        this.appEvents.trigger("post:highlight", closest)
+      );
 
-    const opts = {};
-    if (document.location.hash) {
-      opts.anchor = document.location.hash.slice(1);
-    } else if (_discourse_anchor) {
-      opts.anchor = _discourse_anchor;
-    }
-    DiscourseURL.jumpToPost(closest, opts);
+      const opts = {};
+      if (document.location.hash) {
+        opts.anchor = document.location.hash.slice(1);
+      } else if (_discourse_anchor) {
+        opts.anchor = _discourse_anchor;
+      }
+      DiscourseURL.jumpToPost(closest, opts);
 
-    // completely clear out all the bookmark related attributes
-    // because they are not in the response if bookmarked == false
-    if (closestPost && !closestPost.bookmarked) {
-      closestPost.clearBookmark();
+      // completely clear out all the bookmark related attributes
+      // because they are not in the response if bookmarked == false
+      if (!closestPost.bookmarked) {
+        closestPost.clearBookmark();
+      }
     }
 
     if (!isEmpty(topic.draft) && !EmbedMode.enabled) {
diff --git a/frontend/discourse/app/services/warp-store.js b/frontend/discourse/app/services/warp-store.js
new file mode 100644
index 00000000000..e78b3dfc2f8
--- /dev/null
+++ b/frontend/discourse/app/services/warp-store.js
@@ -0,0 +1,13 @@
+import { JSONAPICache } from "@warp-drive/json-api";
+import { useLegacyStore } from "@warp-drive/legacy";
+import discourseRestHandler from "discourse/data/handlers/discourse-rest";
+import { schemas } from "discourse/data/schemas";
+
+// `linksMode: true` skips the LegacyNetworkHandler so our handler is the
+// sole network layer (routes through Discourse's `ajax()` helper).
+export default class WarpStore extends useLegacyStore({
+  cache: JSONAPICache,
+  schemas,
+  handlers: [discourseRestHandler],
+  linksMode: true,
+}) {}
diff --git a/frontend/discourse/babel.config.cjs b/frontend/discourse/babel.config.cjs
index 9155ea91244..7932747bf04 100644
--- a/frontend/discourse/babel.config.cjs
+++ b/frontend/discourse/babel.config.cjs
@@ -1,4 +1,7 @@
 const { buildMacros } = require("@embroider/macros/babel");
+const {
+  setConfig: setWarpDriveConfig,
+} = require("@warp-drive/core/build-config");
 const StripTestSelectors = require("strip-test-selectors");
 
 const macros = buildMacros({
@@ -6,6 +9,10 @@ const macros = buildMacros({
     macrosConfig.setGlobalConfig(__filename, "@embroider/core", {
       active: true,
     });
+    // WarpDrive build config (previously wired via setConfig in ember-cli-build.js).
+    // Feeds into our existing @embroider/macros config rather than a second
+    // instance, which would duplicate the macros babel plugin.
+    setWarpDriveConfig(macrosConfig, { compatWith: "5.9" });
   },
 });
 
diff --git a/frontend/discourse/package.json b/frontend/discourse/package.json
index f9bbf7a1eff..80ddb4437e5 100644
--- a/frontend/discourse/package.json
+++ b/frontend/discourse/package.json
@@ -58,6 +58,11 @@
     "@lezer/highlight": "^1.2.3",
     "@lezer/javascript": "^1.5.4",
     "@lezer/lr": "^1.4.8",
+    "@warp-drive/core": "5.9.0-alpha.15",
+    "@warp-drive/ember": "5.9.0-alpha.15",
+    "@warp-drive/json-api": "5.9.0-alpha.15",
+    "@warp-drive/legacy": "5.9.0-alpha.15",
+    "@warp-drive/utilities": "5.9.0-alpha.15",
     "ace-builds": "^1.44.0",
     "chart.js": "4.5.1",
     "chartjs-adapter-moment": "^1.0.1",
diff --git a/frontend/discourse/tests/setup-tests.js b/frontend/discourse/tests/setup-tests.js
index f2800a614a2..7f5b0dadfd9 100644
--- a/frontend/discourse/tests/setup-tests.js
+++ b/frontend/discourse/tests/setup-tests.js
@@ -19,6 +19,7 @@ import "message-bus-client";
 import * as FakerModule from "@faker-js/faker";
 import QUnit from "qunit";
 import sinon from "sinon";
+import { clearExtraAttributes } from "discourse/data/extra-attributes";
 import { setDefaultOwner } from "discourse/lib/get-owner";
 import { setupS3CDN, setupURL } from "discourse/lib/get-url";
 import { setLoadedFaker } from "discourse/lib/load-faker";
@@ -350,6 +351,7 @@ export default async function setupTests(config) {
     testContainer.scrollLeft = 0;
 
     flushMap();
+    clearExtraAttributes();
 
     window.MessageBus.unsubscribe("*");
     localStorage.clear();
diff --git a/frontend/discourse/tests/unit/lib/warp-model-extensions-test.js b/frontend/discourse/tests/unit/lib/warp-model-extensions-test.js
new file mode 100644
index 00000000000..0d8fc7fe295
--- /dev/null
+++ b/frontend/discourse/tests/unit/lib/warp-model-extensions-test.js
@@ -0,0 +1,358 @@
+import { addObserver } from "@ember/object/observers";
+import { getOwner } from "@ember/owner";
+import { settled } from "@ember/test-helpers";
+import { setupTest } from "ember-qunit";
+import { module, test } from "qunit";
+import { rollbackAllPrepends } from "discourse/lib/class-prepend";
+import {
+  modelNameFor,
+  resetModelExtensions,
+} from "discourse/lib/model-extensions";
+import { withPluginApi } from "discourse/lib/plugin-api";
+import { isTrackedArray } from "discourse/lib/tracked-tools";
+import Badge from "discourse/models/badge";
+import pretender, {
+  parsePostData,
+  response,
+} from "discourse/tests/helpers/create-pretender";
+
+// Mirrors `model-extensions-test.js`, but exercises the extension APIs against a
+// WarpDrive-backed model (`badge`) rather than a `RestModel`.
+module("Unit | Lib | model-extensions (WarpDrive)", function (hooks) {
+  setupTest(hooks);
+
+  hooks.beforeEach(function () {
+    this.store = getOwner(this).lookup("service:store");
+  });
+
+  hooks.afterEach(function () {
+    rollbackAllPrepends();
+    resetModelExtensions();
+  });
+
+  test("modelNameFor resolves via `static type` without stamping", function (assert) {
+    const badge = this.store.createRecord("badge", { name: "a" });
+    assert.strictEqual(modelNameFor(badge), "badge");
+  });
+
+  test("addModelField uses the default until a server value overrides it", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "rank", { defaultValue: 5 })
+    );
+
+    const record = this.store.createRecord("badge", { name: "a" });
+    assert.strictEqual(record.rank, 5, "falls back to the default");
+
+    record.rank = 9;
+    assert.strictEqual(record.rank, 9, "the field is writable and tracked");
+
+    const fromServer = this.store.createRecord("badge", { name: "b", rank: 7 });
+    assert.strictEqual(fromServer.rank, 7, "a server value wins");
+  });
+
+  test("addModelField type array gives per-instance tracked arrays", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "extras", { type: "array", defaultValue: [] })
+    );
+
+    const a = this.store.createRecord("badge", { name: "a" });
+    const b = this.store.createRecord("badge", { name: "b" });
+
+    assert.true(isTrackedArray(a.extras), "the default is a tracked array");
+
+    a.extras.push("x");
+    assert.deepEqual([...a.extras], ["x"]);
+    assert.deepEqual([...b.extras], [], "each record gets its own array");
+
+    a.extras = ["y", "z"];
+    assert.true(isTrackedArray(a.extras), "an assigned plain array is coerced");
+    assert.deepEqual([...a.extras], ["y", "z"]);
+  });
+
+  test("addModelField type array coerces a server-provided array", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "extras", { type: "array" })
+    );
+
+    const record = this.store.createRecord("badge", {
+      name: "a",
+      extras: ["p", "q"],
+    });
+
+    assert.true(isTrackedArray(record.extras));
+    assert.deepEqual([...record.extras], ["p", "q"]);
+  });
+
+  test("addModelField type object gives a per-instance tracked object", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "bag", { type: "object" })
+    );
+
+    const a = this.store.createRecord("badge", { name: "a" });
+    const b = this.store.createRecord("badge", { name: "b" });
+
+    assert.notStrictEqual(a.bag, b.bag, "each record gets its own object");
+    a.bag.x = 1;
+    assert.strictEqual(b.bag.x, undefined, "mutations do not leak");
+  });
+
+  test("addModelField type set gives a per-instance tracked set", function (assert) {
+    withPluginApi((api) => api.addModelField("badge", "seen", { type: "set" }));
+
+    const a = this.store.createRecord("badge", { name: "a" });
+    const b = this.store.createRecord("badge", { name: "b" });
+
+    a.seen.add("x");
+    assert.true(a.seen.has("x"));
+    assert.false(b.seen.has("x"), "mutations do not leak");
+  });
+
+  test("addModelField function defaultValue runs per instance", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "bag", { defaultValue: () => ({}) })
+    );
+
+    const a = this.store.createRecord("badge", { name: "a" });
+    const b = this.store.createRecord("badge", { name: "b" });
+
+    assert.notStrictEqual(a.bag, b.bag, "each record gets its own object");
+    a.bag.x = 1;
+    assert.strictEqual(b.bag.x, undefined, "mutations do not leak");
+  });
+
+  test("addModelField resettable resets to the initializer when it changes", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "derivedName", {
+        resettable: true,
+        defaultValue() {
+          return this.name;
+        },
+      })
+    );
+
+    const record = this.store.createRecord("badge", { name: "a" });
+    assert.strictEqual(record.derivedName, "a", "derives from the instance");
+
+    record.derivedName = "manual";
+    assert.strictEqual(
+      record.derivedName,
+      "manual",
+      "a manual set sticks while the derived value is unchanged"
+    );
+
+    record.name = "b";
+    assert.strictEqual(
+      record.derivedName,
+      "b",
+      "resets to the new derived value, discarding the manual set"
+    );
+  });
+
+  test("addModelSaveProperty includes the property in the save payload", async function (assert) {
+    withPluginApi((api) => {
+      api.addModelField("badge", "rank", { defaultValue: 0 });
+      api.addModelSaveProperty("badge", "rank");
+    });
+
+    const record = this.store.createRecord("badge", {
+      id: 42,
+      name: "a",
+      rank: 7,
+    });
+
+    pretender.put("/admin/badges/42", (request) => {
+      const params = parsePostData(request.requestBody);
+      assert.strictEqual(params.rank, "7", "merged into the payload");
+      assert.step("called API");
+      return response({});
+    });
+
+    await record.save({ name: "a" });
+    assert.verifySteps(["called API"]);
+  });
+
+  test("addModelSaveProperty accepts a value function", async function (assert) {
+    withPluginApi((api) =>
+      api.addModelSaveProperty("badge", "derived_name", function () {
+        return this.name.toUpperCase();
+      })
+    );
+
+    const record = this.store.createRecord("badge", { id: 43, name: "abc" });
+
+    pretender.put("/admin/badges/43", (request) => {
+      const params = parsePostData(request.requestBody);
+      assert.strictEqual(params.derived_name, "ABC", "computed value merged");
+      assert.step("called API");
+      return response({});
+    });
+
+    await record.save({ name: "abc" });
+    assert.verifySteps(["called API"]);
+  });
+
+  test("addModelCallback init fires after the create args are applied", function (assert) {
+    const seen = [];
+    withPluginApi((api) =>
+      api.addModelCallback("badge", "init", function () {
+        seen.push(this.name);
+      })
+    );
+
+    this.store.createRecord("badge", { name: "a" });
+    assert.deepEqual(seen, ["a"], "runs once, with the assigned args visible");
+  });
+
+  test("addModelCallback afterCreate fires on create", async function (assert) {
+    withPluginApi((api) =>
+      api.addModelCallback("badge", "afterCreate", () => assert.step("create"))
+    );
+
+    const record = this.store.createRecord("badge", { name: "a" });
+
+    pretender.post("/admin/badges", () => {
+      assert.step("api");
+      return response({});
+    });
+
+    await record.save();
+    assert.verifySteps(
+      ["api", "create"],
+      "afterCreate fires after the request"
+    );
+  });
+
+  test("addModelCallback afterUpdate fires on update", async function (assert) {
+    withPluginApi((api) =>
+      api.addModelCallback("badge", "afterUpdate", () => assert.step("update"))
+    );
+
+    const record = this.store.createRecord("badge", { id: 88, name: "a" });
+
+    pretender.put("/admin/badges/88", () => {
+      assert.step("api");
+      return response({});
+    });
+
+    await record.save({ name: "b" });
+    assert.verifySteps(
+      ["api", "update"],
+      "afterUpdate fires after the request"
+    );
+  });
+
+  test("addModelCallback fires destroy callbacks around the request", async function (assert) {
+    withPluginApi((api) => {
+      api.addModelCallback("badge", "beforeDestroy", () =>
+        assert.step("before")
+      );
+      api.addModelCallback("badge", "afterDestroy", () => assert.step("after"));
+    });
+
+    const record = this.store.createRecord("badge", { id: 5, name: "a" });
+
+    pretender.delete("/admin/badges/5", () => {
+      assert.step("api");
+      return response({});
+    });
+
+    await record.destroy();
+    assert.verifySteps(["before", "api", "after"]);
+  });
+
+  test("addModelGetter adds a getter-only derived property", function (assert) {
+    withPluginApi((api) =>
+      api.addModelGetter("badge", "upperName", function () {
+        return this.name?.toUpperCase();
+      })
+    );
+
+    const record = this.store.createRecord("badge", { name: "abc" });
+    assert.strictEqual(record.upperName, "ABC");
+  });
+
+  test("addModelSetter adds a setter-only accessor", function (assert) {
+    withPluginApi((api) =>
+      api.addModelSetter("badge", "shout", function (value) {
+        this.name = value.toLowerCase();
+      })
+    );
+
+    const record = this.store.createRecord("badge", { name: "x" });
+    record.shout = "HELLO";
+    assert.strictEqual(record.name, "hello");
+  });
+
+  test("addModelAccessor adds a property with a getter and a setter", function (assert) {
+    withPluginApi((api) =>
+      api.addModelAccessor("badge", "upperName", {
+        get() {
+          return this.name?.toUpperCase();
+        },
+        set(value) {
+          this.name = value.toLowerCase();
+        },
+      })
+    );
+
+    const record = this.store.createRecord("badge", { name: "abc" });
+    assert.strictEqual(record.upperName, "ABC", "the getter derives a value");
+
+    record.upperName = "XYZ";
+    assert.strictEqual(record.name, "xyz", "the setter runs");
+    assert.strictEqual(record.upperName, "XYZ");
+  });
+
+  test("addModelMethod adds an instance method", function (assert) {
+    withPluginApi((api) =>
+      api.addModelMethod("badge", "greet", function () {
+        return `${this.name}!`;
+      })
+    );
+
+    const record = this.store.createRecord("badge", { name: "hi" });
+    assert.strictEqual(record.greet(), "hi!");
+  });
+
+  test("addModelGetter is observable by classic observers (dependentKeyCompat)", async function (assert) {
+    withPluginApi((api) => {
+      api.addModelField("badge", "count", { defaultValue: 1 });
+      api.addModelGetter("badge", "doubled", function () {
+        return this.count * 2;
+      });
+    });
+
+    const record = this.store.createRecord("badge", { name: "a" });
+    assert.strictEqual(record.doubled, 2, "derives from the tracked field");
+
+    // eslint-disable-next-line ember/no-observers -- verifies classic-observer interop
+    addObserver(record, "doubled", () => assert.step("changed"));
+    record.count = 5;
+    await settled();
+
+    assert.verifySteps(["changed"], "a classic observer fires on change");
+    assert.strictEqual(record.doubled, 10);
+  });
+
+  test("addModelField applies to records loaded from the server", async function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("badge", "rank", { defaultValue: 5 })
+    );
+
+    pretender.get("/badges.json", () =>
+      response({
+        badges: [{ id: 1, name: "a", badge_type_id: 1 }],
+        badge_types: [{ id: 1, name: "Gold" }],
+        badge_groupings: [],
+      })
+    );
+
+    const badges = await Badge.findAll();
+    assert.strictEqual(badges.length, 1, "loads the badge");
+    assert.strictEqual(
+      badges[0].rank,
+      5,
+      "reads the registered field off a cached record"
+    );
+  });
+});
diff --git a/frontend/discourse/tests/unit/models/topic-details-test.js b/frontend/discourse/tests/unit/models/topic-details-test.js
index 11f48c63220..017093a3e78 100644
--- a/frontend/discourse/tests/unit/models/topic-details-test.js
+++ b/frontend/discourse/tests/unit/models/topic-details-test.js
@@ -1,6 +1,8 @@
 import { getOwner } from "@ember/owner";
 import { setupTest } from "ember-qunit";
 import { module, test } from "qunit";
+import { withPluginApi } from "discourse/lib/plugin-api";
+import TopicDetails from "discourse/models/topic-details";
 import User from "discourse/models/user";
 
 module("Unit | Model | topic-details", function (hooks) {
@@ -31,4 +33,35 @@ module("Unit | Model | topic-details", function (hooks) {
     );
     assert.containsInstance(details.allowed_users, User);
   });
+
+  // The base constructor seeds registered fields and fires `init` callbacks
+  // before this subclass's own (private) state exists.
+  test("a plugin init callback can read id and __resource during construction", function (assert) {
+    let seen;
+    withPluginApi((api) =>
+      api.addModelCallback("topic-details", "init", function () {
+        seen = { id: this.id, resource: this.__resource };
+      })
+    );
+
+    const details = TopicDetails.create({ id: 123 });
+
+    assert.deepEqual(
+      seen,
+      { id: null, resource: undefined },
+      "reports no id while the base constructor runs"
+    );
+    assert.strictEqual(details.id, "123", "resolves the id afterwards");
+  });
+
+  test("a plugin-registered field seeds its default", function (assert) {
+    withPluginApi((api) =>
+      api.addModelField("topic-details", "pluginFlag", { defaultValue: 7 })
+    );
+
+    const details = TopicDetails.create({ id: 55 });
+
+    assert.strictEqual(details.pluginFlag, 7, "applies the registered default");
+    assert.strictEqual(details.id, "55");
+  });
 });
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 0c83475e179..bfa9c2cc293 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -306,6 +306,21 @@ importers:
       '@lezer/lr':
         specifier: ^1.4.8
         version: 1.4.10
+      '@warp-drive/core':
+        specifier: 5.9.0-alpha.15
+        version: 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/ember':
+        specifier: 5.9.0-alpha.15
+        version: 5.9.0-alpha.15(@babel/core@7.29.7)(@ember/test-waiters@4.1.1(@babel/core@7.29.7)(@glint/template@1.7.8))(@glint/template@1.7.8)
+      '@warp-drive/json-api':
+        specifier: 5.9.0-alpha.15
+        version: 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))
+      '@warp-drive/legacy':
+        specifier: 5.9.0-alpha.15
+        version: 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))(@warp-drive/utilities@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)))
+      '@warp-drive/utilities':
+        specifier: 5.9.0-alpha.15
+        version: 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))
       ace-builds:
         specifier: ^1.44.0
         version: 1.44.0
@@ -3233,6 +3248,37 @@ packages:
   '@vscode/l10n@0.0.18':
     resolution: {integrity: sha512-KYSIHVmslkaCDyw013pphY+d7x1qV8IZupYfeIfzNA+nsaWHbn5uPuQRvdRFsa9zFzGeudPuoGoZ1Op4jrJXIQ==}
 
+  '@warp-drive/build-config@5.9.0-alpha.15':
+    resolution: {integrity: sha512-mZgJSAfowe8IkjWe+7RmZtD17ZM9XdUKPWvYeLY4xcNW50AirD9f3kNcaMQo81h7al7b3tSOA32RRBABcI65Wg==}
+
+  '@warp-drive/core@5.9.0-alpha.15':
+    resolution: {integrity: sha512-WckK31nhuv5n/KDHusPmVMaj6FYR/Us6Zu2ppU7rRO7H6YfZMC+9Lp2q+in0vD9WhMtcOt85dTxMpzfElwv67Q==}
+
+  '@warp-drive/ember@5.9.0-alpha.15':
+    resolution: {integrity: sha512-VcQDendVOwDwcyxz5CCGaCUqs3/fhYJ6meGBOLhbnxyQ4O26pdU1vb443TKL0B6WVd6DaoPTV6MG3lfxezZA/w==}
+    peerDependencies:
+      '@ember/test-waiters': 4.1.1
+      ember-provide-consume-context: ^0.8.0
+    peerDependenciesMeta:
+      ember-provide-consume-context:
+        optional: true
+
+  '@warp-drive/json-api@5.9.0-alpha.15':
+    resolution: {integrity: sha512-LgPHAd3QavtnNMBJzRghLX1jHci3sb4mbl01G9/29fxgpCS/baFFg7ANx3s14m2H3Cjg5+bktEdEAKXsqib92A==}
+    peerDependencies:
+      '@warp-drive/core': 5.9.0-alpha.15
+
+  '@warp-drive/legacy@5.9.0-alpha.15':
+    resolution: {integrity: sha512-69Y/04GC66zpZn6bxjKwcHRkJBMHaZf4xFS4KoKT6MIRKO+JW53DO2ixH3tZP7Zksrbtyaka8vq0HXPbOzrGWg==}
+    peerDependencies:
+      '@warp-drive/core': 5.9.0-alpha.15
+      '@warp-drive/utilities': 5.9.0-alpha.15
+
+  '@warp-drive/utilities@5.9.0-alpha.15':
+    resolution: {integrity: sha512-de/7szw8Qaz6rVv4mxQ3L00iKMhGHlRgTdiOYhq74PEGFrqSdv91sdVB+WOVjVhSdCrvs06FoUhkSZQ0Us/jxQ==}
+    peerDependencies:
+      '@warp-drive/core': 5.9.0-alpha.15
+
   '@xmldom/xmldom@0.9.10':
     resolution: {integrity: sha512-A9gOqLdi6cV4ibazAjcQufGj0B1y/vDqYrcuP6d/6x8P27gRS8643Dj9o1dEKtB6O7fwxb2FgBmJS2mX7gpvdw==}
     engines: {node: '>=14.6'}
@@ -3906,6 +3952,10 @@ packages:
     resolution: {integrity: sha512-FMabTRlc5t5zjdenF6mS0MBeFZm0XqHqeOkcskKFb/LYCcRQ5fVgLOHVc4Lq9CqABd9zhjwPjMBCJvMCziSVtA==}
     engines: {node: ^14.17.0 || ^16.13.0 || >=18.0.0}
 
+  code-error-fragment@0.0.230:
+    resolution: {integrity: sha512-cadkfKp6932H8UkhzE/gcUqhRMNf8jHzkAN7+5Myabswaghu4xABTgPHDCjW+dBAJxj/SpkTYokpzDqY4pCzQw==}
+    engines: {node: '>= 4'}
+
   codemirror@6.0.2:
     resolution: {integrity: sha512-VhydHotNW5w1UGK0Qj96BwSk/Zqbp9WbnyK2W/eVMv4QyF41INRGpjUhFJY7/uDNuudSc33a/PKr4iDqRduvHw==}
 
@@ -5118,6 +5168,10 @@ packages:
   functions-have-names@1.2.3:
     resolution: {integrity: sha512-xckBUXyTIqT97tq2x2AMb+g163b5JFysYk0x4qxNFwbfQkmNZoiRHb6sPzI9/QV33WeuvVYBUIiD4NzNIyqaRQ==}
 
+  fuse.js@7.1.0:
+    resolution: {integrity: sha512-trLf4SzuuUxfusZADLINj+dE8clK1frKdmqiJNb1Es75fmI5oY6X2mxLVUciLLjxqw/xr72Dhy+lER6dGd02FQ==}
+    engines: {node: '>=10'}
+
   gauge@5.0.2:
     resolution: {integrity: sha512-pMaFftXPtiGIHCJHdcUUx9Rby/rFT/Kkt3fIIGCs+9PMDIljSyRiqraTlxNtBReJRDfUefpa263RQ3vnp5G/LQ==}
     engines: {node: ^14.17.0 || ^16.13.0 || >=18.0.0}
@@ -5251,6 +5305,9 @@ packages:
   graceful-fs@4.2.11:
     resolution: {integrity: sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ==}
 
+  grapheme-splitter@1.0.4:
+    resolution: {integrity: sha512-bzh50DW9kTPM00T8y4o8vQg89Di9oLJVLW/KaOGIXJWP/iqCN6WKYkbNOF04vFLJhwcpYUh9ydh/+5vpOqV4YQ==}
+
   growly@1.3.0:
     resolution: {integrity: sha512-+xGQY0YyAWCnqy7Cd++hc2JqMYzlm0dG30Jd0beaA64sROr8C4nt8Yc9V5Ro3avlSUDTN0ulqP/VBKi1/lLygw==}
 
@@ -5837,6 +5894,10 @@ packages:
   json-stringify-nice@1.1.4:
     resolution: {integrity: sha512-5Z5RFW63yxReJ7vANgW6eZFGWaQvnPE3WNmZoOJrSkGju2etKA2L5rrOa1sm877TVTFt57A80BH1bArcmlLfPw==}
 
+  json-to-ast@2.1.0:
+    resolution: {integrity: sha512-W9Lq347r8tA1DfMvAGn9QNcgYm4Wm7Yc+k8e6vezpMnRT+NHbtlxgNBXRVjXe9YM6eTn6+p/MKOlV/aABJcSnQ==}
+    engines: {node: '>= 4'}
+
   json5@1.0.2:
     resolution: {integrity: sha512-g1MWMLBiz8FKi1e4w0UyVL3w+iJceWAFBAaBnnGKOpNa5f8TLktkbre1+s6oICydWAm+HRUGTmI+//xv2hvXYA==}
     hasBin: true
@@ -11289,6 +11350,67 @@ snapshots:
 
   '@vscode/l10n@0.0.18': {}
 
+  '@warp-drive/build-config@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)':
+    dependencies:
+      '@embroider/addon-shim': 1.10.3
+      '@embroider/macros': 1.20.6(@babel/core@7.29.7)(@glint/template@1.7.8)
+      babel-import-util: 2.1.1
+      babel-plugin-debug-macros: 2.0.0(@babel/core@7.29.7)
+      semver: 7.8.5
+    transitivePeerDependencies:
+      - '@babel/core'
+      - '@glint/template'
+      - supports-color
+
+  '@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)':
+    dependencies:
+      '@embroider/macros': 1.20.6(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/build-config': 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)
+    transitivePeerDependencies:
+      - '@babel/core'
+      - '@glint/template'
+      - supports-color
+
+  '@warp-drive/ember@5.9.0-alpha.15(@babel/core@7.29.7)(@ember/test-waiters@4.1.1(@babel/core@7.29.7)(@glint/template@1.7.8))(@glint/template@1.7.8)':
+    dependencies:
+      '@ember/test-waiters': 4.1.1(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@embroider/macros': 1.20.6(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/core': 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)
+    transitivePeerDependencies:
+      - '@babel/core'
+      - '@glint/template'
+      - supports-color
+
+  '@warp-drive/json-api@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))':
+    dependencies:
+      '@embroider/macros': 1.20.6(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/core': 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)
+      fuse.js: 7.1.0
+      json-to-ast: 2.1.0
+    transitivePeerDependencies:
+      - '@babel/core'
+      - '@glint/template'
+      - supports-color
+
+  '@warp-drive/legacy@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))(@warp-drive/utilities@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)))':
+    dependencies:
+      '@embroider/macros': 1.20.6(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/core': 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/utilities': 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))
+    transitivePeerDependencies:
+      - '@babel/core'
+      - '@glint/template'
+      - supports-color
+
+  '@warp-drive/utilities@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)(@warp-drive/core@5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8))':
+    dependencies:
+      '@embroider/macros': 1.20.6(@babel/core@7.29.7)(@glint/template@1.7.8)
+      '@warp-drive/core': 5.9.0-alpha.15(@babel/core@7.29.7)(@glint/template@1.7.8)
+    transitivePeerDependencies:
+      - '@babel/core'
+      - '@glint/template'
+      - supports-color
+
   '@xmldom/xmldom@0.9.10': {}
 
   a11y-dialog@8.1.5:
@@ -12150,6 +12272,8 @@ snapshots:
 
   cmd-shim@6.0.3: {}
 
+  code-error-fragment@0.0.230: {}
+
   codemirror@6.0.2:
     dependencies:
       '@codemirror/autocomplete': 6.20.3
@@ -13834,6 +13958,8 @@ snapshots:
 
   functions-have-names@1.2.3: {}
 
+  fuse.js@7.1.0: {}
+
   gauge@5.0.2:
     dependencies:
       aproba: 2.1.0
@@ -13998,6 +14124,8 @@ snapshots:
 
   graceful-fs@4.2.11: {}
 
+  grapheme-splitter@1.0.4: {}
+
   growly@1.3.0: {}
 
   handlebars@4.7.9:
@@ -14590,6 +14718,11 @@ snapshots:
 
   json-stringify-nice@1.1.4: {}
 
+  json-to-ast@2.1.0:
+    dependencies:
+      code-error-fragment: 0.0.230
+      grapheme-splitter: 1.0.4
+
   json5@1.0.2:
     dependencies:
       minimist: 1.2.8