diff --git a/.changeset/i18n-translations-request-drop-phantom-filters.md b/.changeset/i18n-translations-request-drop-phantom-filters.md
new file mode 100644
index 0000000000..fec49970bf
--- /dev/null
+++ b/.changeset/i18n-translations-request-drop-phantom-filters.md
@@ -0,0 +1,54 @@
+---
+"@objectstack/spec": minor
+"@objectstack/client": minor
+---
+
+fix(spec,client)!: `GetTranslationsRequest` is locale-only — drop the
+`namespace` / `keys` filters no server ever read (#3676)
+
+`GetTranslationsRequestSchema` declared two optional filters, and the endpoint
+description promised one of them ("...for the specified locale and optional
+namespace"). Neither serving surface read either: the dispatcher domain body
+(`runtime/src/domains/i18n.ts`) takes `parts[1]` / `query.locale`, and
+service-i18n (`i18n-service-plugin.ts`) takes `req.params.locale`. Both return
+the locale's whole bundle. The SDK meanwhile put both on the query string, so a
+caller who passed `keys` to shrink the response shrank nothing and got no
+indication the filter was inert — Prime Directive #10's declared ≠ enforced, the
+same shape #1475 trimmed out of the validation-rule types.
+
+Trimmed rather than implemented, on three counts:
+
+- **No consumer.** No call site in this repo or `objectui` passed either field.
+  The docs (`content/docs/api/client-sdk.mdx`, `skills/objectstack-i18n/SKILL.md`)
+  already documented `getTranslations(locale)` as a full-bundle snapshot, so the
+  schema was the outlier, not the docs. The one thing that did exercise them was
+  a client test asserting the query string got *built* — it pinned the phantom
+  rather than any behaviour, since no server read what it asserted was sent. It
+  is replaced here by its inverse: a regression test that the request carries no
+  filter query at all.
+- **`keys` could not deliver what it advertises.** `II18nService.getTranslations`
+  (`contracts/i18n-service.ts`) takes only `locale`, so a filter could only be a
+  post-filter over an already-materialized bundle. `keys` reads as a payload
+  optimization; a post-filter saves wire bytes but none of the server work, and
+  widening the contract would break every implementer (`memory-i18n`,
+  `file-i18n-adapter`) for a capability with no caller.
+- **`keys` has no defined meaning against the current bundle shape.** Under the
+  retired flat `o.`-dotted dialect, `keys: ['o.account.label']` was an obvious
+  pick. #3778 settled the tree on one nested `TranslationData` shape, where a
+  flat `string[]` is neither a path set nor a group set, and a filtered response
+  would have to be rebuilt as a sparse nested tree to stay schema-valid. That is
+  a design decision, and nothing is waiting on it.
+
+`namespace` is the one that got *easier* — it now lands exactly on
+`TranslationData`'s top-level groups, which is what its own description already
+said ("e.g., objects, apps, messages"). It is still trimmed here: re-adding an
+optional request field is additive and non-breaking the day the Studio's
+per-module views actually need it, whereas shipping an unexercised filter path
+now means dead code with tests to match, and a declared-but-unread field is
+precisely the exemplar the next author copies.
+
+BREAKING: the two schema fields and the `getTranslations(locale, options?)`
+second parameter are removed with no deprecation cycle. Nothing worked through
+them — a passed filter was silently ignored — so there is no behavior to
+protect. Runtime impact is nil (the fields were optional and now strip); TS
+callers passing them fail to compile, which is the intended signal.
diff --git a/content/docs/references/api/protocol.mdx b/content/docs/references/api/protocol.mdx
index a8953e7331..a4f123fdc4 100644
--- a/content/docs/references/api/protocol.mdx
+++ b/content/docs/references/api/protocol.mdx
@@ -711,8 +711,6 @@ const result = AiInsightsRequest.parse(data);
 | Property | Type | Required | Description |
 | :--- | :--- | :--- | :--- |
 | **locale** | `string` | ✅ | BCP-47 locale code |
-| **namespace** | `string` | optional | Translation namespace (e.g., objects, apps, messages) |
-| **keys** | `string[]` | optional | Specific translation keys to fetch |
 
 
 ---
diff --git a/packages/client/src/client.test.ts b/packages/client/src/client.test.ts
index 1d2a0c6d4f..d0d16f1f80 100644
--- a/packages/client/src/client.test.ts
+++ b/packages/client/src/client.test.ts
@@ -656,15 +656,23 @@ describe('i18n namespace', () => {
         );
     });
 
-    it('i18n.getTranslations keeps namespace/keys as query params on the path form', async () => {
+    it('i18n.getTranslations sends no filter query — the server reads none (#3676)', async () => {
         const { client, fetchMock } = createMockClient({
             success: true,
             data: { locale: 'zh-CN', translations: { hello: '你好' } }
         });
-        await client.i18n.getTranslations('zh-CN', { namespace: 'common', keys: ['a', 'b'] });
-        expect(String(fetchMock.mock.calls[0][0])).toBe(
-            'http://localhost:3000/api/v1/i18n/translations/zh-CN?namespace=common&keys=a%2Cb',
+        // This used to accept `{ namespace, keys }` and append them as query
+        // params. Neither serving surface ever read them (the dispatcher takes
+        // parts[1]/query.locale, service-i18n takes params.locale), so the
+        // filter was inert and the caller got the full bundle either way. The
+        // predecessor of this test asserted the query string was BUILT, which
+        // pinned the phantom in place rather than the behaviour.
+        await (client.i18n.getTranslations as (l: string, o?: unknown) => Promise<unknown>)(
+            'zh-CN', { namespace: 'common', keys: ['a', 'b'] },
         );
+        const url = String(fetchMock.mock.calls[0][0]);
+        expect(url).toBe('http://localhost:3000/api/v1/i18n/translations/zh-CN');
+        expect(url).not.toContain('?');
     });
 
     it('i18n.getFieldLabels puts both object and locale on the path (#3636)', async () => {
diff --git a/packages/client/src/index.ts b/packages/client/src/index.ts
index 6d33585942..3d9ace120c 100644
--- a/packages/client/src/index.ts
+++ b/packages/client/src/index.ts
@@ -3510,15 +3510,16 @@ export class ObjectStackClient {
      * The `?locale=` query form this used to send matched no route anywhere
      * and 404'd on the wire; the dispatcher's domain body accepts it, but
      * nothing ever routes a bare `/translations` to that body (#3636).
+     *
+     * Returns the locale's full bundle. The `options.namespace` / `options.keys`
+     * this used to accept rode the query string to a server that read neither,
+     * so the filter silently did nothing — trimmed with the request schema's
+     * fields in #3676.
      */
-    getTranslations: async (locale: string, options?: { namespace?: string; keys?: string[] }): Promise<GetTranslationsResponse> => {
+    getTranslations: async (locale: string): Promise<GetTranslationsResponse> => {
       const route = this.getRoute('i18n');
-      const params = new URLSearchParams();
-      if (options?.namespace) params.set('namespace', options.namespace);
-      if (options?.keys) params.set('keys', options.keys.join(','));
-      const query = params.toString();
       const res = await this.fetch(
-        `${this.baseUrl}${route}/translations/${encodeURIComponent(locale)}${query ? `?${query}` : ''}`,
+        `${this.baseUrl}${route}/translations/${encodeURIComponent(locale)}`,
       );
       return this.unwrapResponse<GetTranslationsResponse>(res);
     },
diff --git a/packages/spec/src/api/plugin-rest-api.zod.ts b/packages/spec/src/api/plugin-rest-api.zod.ts
index fedf82524f..319f432694 100644
--- a/packages/spec/src/api/plugin-rest-api.zod.ts
+++ b/packages/spec/src/api/plugin-rest-api.zod.ts
@@ -1182,7 +1182,7 @@ export const DEFAULT_I18N_ROUTES: RestApiRouteRegistration = {
       category: 'i18n',
       public: false,
       summary: 'Get translations for a locale',
-      description: 'Returns translation strings for the specified locale and optional namespace',
+      description: "Returns the specified locale's full translation bundle",
       tags: ['i18n'],
       responseSchema: 'GetTranslationsResponseSchema',
       cacheable: true,
diff --git a/packages/spec/src/api/protocol.test.ts b/packages/spec/src/api/protocol.test.ts
index d8dd372f4a..00f981ffec 100644
--- a/packages/spec/src/api/protocol.test.ts
+++ b/packages/spec/src/api/protocol.test.ts
@@ -302,7 +302,14 @@ describe('ObjectStack Protocol', () => {
         { code: 'es-ES', label: 'Spanish (Spain)' },
       ],
     }).success).toBe(true);
-    expect(GetTranslationsRequestSchema.safeParse({ locale: 'en-US', namespace: 'objects' }).success).toBe(true);
+    expect(GetTranslationsRequestSchema.safeParse({ locale: 'en-US' }).success).toBe(true);
+    // The request is locale-only. `namespace`/`keys` were declared here but read
+    // by no serving surface, so they were trimmed (#3676). Asserting on the
+    // PARSED OUTPUT is the point: `safeParse` still succeeds on a payload
+    // carrying them (z.object strips unknown keys), so a success-only assertion
+    // would keep passing green whether the fields were trimmed or not.
+    const trimmed = GetTranslationsRequestSchema.parse({ locale: 'en-US', namespace: 'objects', keys: ['a'] });
+    expect(trimmed).toEqual({ locale: 'en-US' });
     expect(GetTranslationsResponseSchema.safeParse({
       locale: 'en-US',
       translations: { objects: { task: { label: 'Task', pluralLabel: 'Tasks' } }, messages: { save: 'Save' } },
diff --git a/packages/spec/src/api/protocol.zod.ts b/packages/spec/src/api/protocol.zod.ts
index 3219e6e8c6..8cbe246a76 100644
--- a/packages/spec/src/api/protocol.zod.ts
+++ b/packages/spec/src/api/protocol.zod.ts
@@ -954,10 +954,28 @@ export const GetLocalesResponseSchema = lazySchema(() => z.object({
   })).describe('Available locales'),
 }));
 
+/**
+ * `locale` is the whole request — the endpoint returns that locale's full
+ * bundle, and there is no server-side filter to ask for.
+ *
+ * This once declared `namespace` and `keys` filters. Neither serving surface
+ * ever read them: the dispatcher domain body takes `parts[1]`/`query.locale`
+ * and service-i18n takes `req.params.locale`, so both returned the whole
+ * bundle while the SDK dutifully put both on the query string. A caller who
+ * passed `keys` to shrink the payload shrank nothing and was told nothing —
+ * Prime Directive #10's declared ≠ enforced, the shape #1475 trimmed out of
+ * the validation-rule types. Removed rather than implemented (#3676): no
+ * caller in this repo or objectui passed either one, `II18nService`
+ * (`contracts/i18n-service.ts`) takes only `locale` so a filter could only be
+ * a post-filter on an already-materialized bundle — which is precisely not
+ * the server-side work `keys` reads as saving — and against the nested
+ * `TranslationData` shape #3778 settled on, a flat `keys: string[]` has no
+ * defined meaning at all. Re-adding an optional filter is additive and
+ * non-breaking the day a consumer actually needs one; a declared-but-unread
+ * field is the exemplar the next author copies.
+ */
 export const GetTranslationsRequestSchema = lazySchema(() => z.object({
   locale: z.string().describe('BCP-47 locale code'),
-  namespace: z.string().optional().describe('Translation namespace (e.g., objects, apps, messages)'),
-  keys: z.array(z.string()).optional().describe('Specific translation keys to fetch'),
 }));
 
 export const GetTranslationsResponseSchema = lazySchema(() => z.object({