From 615491a3ff86f546b2ea9c0b69ce8585bcf89fe2 Mon Sep 17 00:00:00 2001
From: "emdashbot[bot]" <emdashbot[bot]@users.noreply.github.com>
Date: Mon, 1 Jun 2026 21:31:46 +0000
Subject: [PATCH 1/3] fix(admin/core): forward locale query param through
 content edit route and write handlers (#1242)

---
 .changeset/fix-admin-locale-edit.md           |   5 +
 .changeset/fix-core-locale-write.md           |   5 +
 .../admin/src/components/ContentEditor.tsx    |   1 +
 packages/admin/src/components/ContentList.tsx |   1 +
 packages/admin/src/lib/api/content.ts         |  78 ++++--
 packages/admin/src/router.tsx                 |  67 +++--
 .../routes/api/content/[collection]/[id].ts   |  10 +-
 .../[collection]/[id]/discard-draft.ts        |   6 +-
 .../api/content/[collection]/[id]/publish.ts  |   6 +-
 .../api/content/[collection]/[id]/schedule.ts |  12 +-
 .../content/[collection]/[id]/unpublish.ts    |   6 +-
 .../api/content-route-permissions.test.ts     |   4 +
 .../unit/astro/content-route-locale.test.ts   | 238 ++++++++++++++++++
 13 files changed, 393 insertions(+), 46 deletions(-)
 create mode 100644 .changeset/fix-admin-locale-edit.md
 create mode 100644 .changeset/fix-core-locale-write.md
 create mode 100644 packages/core/tests/unit/astro/content-route-locale.test.ts

diff --git a/.changeset/fix-admin-locale-edit.md b/.changeset/fix-admin-locale-edit.md
new file mode 100644
index 000000000..a901331b7
--- /dev/null
+++ b/.changeset/fix-admin-locale-edit.md
@@ -0,0 +1,5 @@
+---
+"@emdash-cms/admin": patch
+---
+
+Forward `locale` query param through admin content edit route and API client to resolve correct i18n variant for slug-based lookups (#1242)
diff --git a/.changeset/fix-core-locale-write.md b/.changeset/fix-core-locale-write.md
new file mode 100644
index 000000000..743513214
--- /dev/null
+++ b/.changeset/fix-core-locale-write.md
@@ -0,0 +1,5 @@
+---
+"emdash": patch
+---
+
+Read `?locale=` in content write routes (PUT, DELETE, publish, unpublish, discard-draft, schedule, unschedule) and forward it to `handleContentGet` for locale-aware slug resolution (#1242)
diff --git a/packages/admin/src/components/ContentEditor.tsx b/packages/admin/src/components/ContentEditor.tsx
index 3f4834b2a..d4aadea19 100644
--- a/packages/admin/src/components/ContentEditor.tsx
+++ b/packages/admin/src/components/ContentEditor.tsx
@@ -1024,6 +1024,7 @@ export function ContentEditor({
 											navigate({
 												to: "/content/$collection/$id",
 												params: { collection, id: tr.id },
+												search: { locale: tr.locale },
 											})
 										}
 										onCreate={onTranslate}
diff --git a/packages/admin/src/components/ContentList.tsx b/packages/admin/src/components/ContentList.tsx
index cd43ea62c..6122fb0b9 100644
--- a/packages/admin/src/components/ContentList.tsx
+++ b/packages/admin/src/components/ContentList.tsx
@@ -621,6 +621,7 @@ function ContentListItem({
 					<RouterLinkButton
 						to="/content/$collection/$id"
 						params={{ collection, id: item.id }}
+						search={{ locale: item.locale }}
 						aria-label={t`Edit ${title}`}
 						variant="ghost"
 						shape="square"
diff --git a/packages/admin/src/lib/api/content.ts b/packages/admin/src/lib/api/content.ts
index 6b5e94a8e..b3b05c633 100644
--- a/packages/admin/src/lib/api/content.ts
+++ b/packages/admin/src/lib/api/content.ts
@@ -164,8 +164,15 @@ export async function fetchContentList(
 /**
  * Fetch single content item
  */
-export async function fetchContent(collection: string, id: string): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}`);
+export async function fetchContent(
+	collection: string,
+	id: string,
+	options?: { locale?: string },
+): Promise<ContentItem> {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}${query}`);
 	const data = await parseApiResponse<{ item: ContentItem }>(response, "Failed to fetch content");
 	return data.item;
 }
@@ -200,8 +207,12 @@ export async function updateContent(
 	collection: string,
 	id: string,
 	input: UpdateContentInput,
+	options?: { locale?: string },
 ): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}`, {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}${query}`, {
 		method: "PUT",
 		headers: { "Content-Type": "application/json" },
 		body: JSON.stringify(input),
@@ -213,8 +224,15 @@ export async function updateContent(
 /**
  * Delete content (moves to trash)
  */
-export async function deleteContent(collection: string, id: string): Promise<void> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}`, {
+export async function deleteContent(
+	collection: string,
+	id: string,
+	options?: { locale?: string },
+): Promise<void> {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}${query}`, {
 		method: "DELETE",
 	});
 	if (!response.ok) await throwResponseError(response, i18n._(msg`Failed to delete content`));
@@ -284,8 +302,12 @@ export async function scheduleContent(
 	collection: string,
 	id: string,
 	scheduledAt: string,
+	options?: { locale?: string },
 ): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/schedule`, {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/schedule${query}`, {
 		method: "POST",
 		headers: { "Content-Type": "application/json" },
 		body: JSON.stringify({ scheduledAt }),
@@ -300,8 +322,15 @@ export async function scheduleContent(
 /**
  * Unschedule content (revert to draft)
  */
-export async function unscheduleContent(collection: string, id: string): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/schedule`, {
+export async function unscheduleContent(
+	collection: string,
+	id: string,
+	options?: { locale?: string },
+): Promise<ContentItem> {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/schedule${query}`, {
 		method: "DELETE",
 	});
 	const data = await parseApiResponse<{ item: ContentItem }>(
@@ -366,8 +395,15 @@ export async function getPreviewUrl(
 /**
  * Publish content - promotes current draft to live
  */
-export async function publishContent(collection: string, id: string): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/publish`, {
+export async function publishContent(
+	collection: string,
+	id: string,
+	options?: { locale?: string },
+): Promise<ContentItem> {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/publish${query}`, {
 		method: "POST",
 	});
 	const data = await parseApiResponse<{ item: ContentItem }>(response, "Failed to publish content");
@@ -377,8 +413,15 @@ export async function publishContent(collection: string, id: string): Promise<Co
 /**
  * Unpublish content - removes from public, preserves draft
  */
-export async function unpublishContent(collection: string, id: string): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/unpublish`, {
+export async function unpublishContent(
+	collection: string,
+	id: string,
+	options?: { locale?: string },
+): Promise<ContentItem> {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/unpublish${query}`, {
 		method: "POST",
 	});
 	const data = await parseApiResponse<{ item: ContentItem }>(
@@ -391,8 +434,15 @@ export async function unpublishContent(collection: string, id: string): Promise<
 /**
  * Discard draft changes - reverts to live version
  */
-export async function discardDraft(collection: string, id: string): Promise<ContentItem> {
-	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/discard-draft`, {
+export async function discardDraft(
+	collection: string,
+	id: string,
+	options?: { locale?: string },
+): Promise<ContentItem> {
+	const params = new URLSearchParams();
+	if (options?.locale) params.set("locale", options.locale);
+	const query = params.toString() ? `?${params}` : "";
+	const response = await apiFetch(`${API_BASE}/content/${collection}/${id}/discard-draft${query}`, {
 		method: "POST",
 	});
 	const data = await parseApiResponse<{ item: ContentItem }>(response, "Failed to discard draft");
diff --git a/packages/admin/src/router.tsx b/packages/admin/src/router.tsx
index 9bc8f2aa1..eba0f5e4b 100644
--- a/packages/admin/src/router.tsx
+++ b/packages/admin/src/router.tsx
@@ -135,9 +135,10 @@ function patchAutosaveQueries(
 			data?: Record<string, unknown>;
 			slug?: string;
 		};
+		locale?: string;
 	},
 ) {
-	const { collection, id, savedItem, payload } = params;
+	const { collection, id, savedItem, payload, locale } = params;
 	const draftRevisionId = savedItem.draftRevisionId;
 
 	if (draftRevisionId) {
@@ -162,7 +163,10 @@ function patchAutosaveQueries(
 		});
 	}
 
-	queryClient.setQueryData<ContentItem>(["content", collection, id], savedItem);
+	queryClient.setQueryData<ContentItem>(
+		locale ? ["content", collection, id, { locale }] : ["content", collection, id],
+		savedItem,
+	);
 }
 
 // Create a base root route without Shell for setup
@@ -582,6 +586,7 @@ const contentEditRoute = createRoute({
 	component: ContentEditPage,
 	validateSearch: (search) => ({
 		...(typeof search.field === "string" && { field: search.field }),
+		...(typeof search.locale === "string" && { locale: search.locale }),
 	}),
 });
 
@@ -606,10 +611,12 @@ function ContentEditPage() {
 	});
 
 	const i18n = manifest?.i18n;
+	const activeLocale = i18n ? (searchParams.locale ?? i18n.defaultLocale) : undefined;
 
 	const { data: rawItem, isLoading } = useQuery({
-		queryKey: ["content", collection, id],
-		queryFn: () => fetchContent(collection, id),
+		queryKey: ["content", collection, id, { locale: activeLocale }],
+		queryFn: () => fetchContent(collection, id, { locale: activeLocale }),
+		enabled: !i18n || !!activeLocale,
 	});
 
 	React.useEffect(() => {
@@ -725,9 +732,11 @@ function ContentEditPage() {
 			bylines?: BylineCreditInput[];
 			skipRevision?: boolean;
 			seo?: ContentSeoInput;
-		}) => updateContent(collection, id, data),
+		}) => updateContent(collection, id, data, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
-			void queryClient.invalidateQueries({ queryKey: ["content", collection, id] });
+			void queryClient.invalidateQueries({
+				queryKey: ["content", collection, id, { locale: rawItem?.locale ?? activeLocale }],
+			});
 			// Also invalidate revisions since a new one was created
 			void queryClient.invalidateQueries({ queryKey: ["revisions", collection, id] });
 			// Invalidate the cached draft revision so stale data doesn't overwrite the form
@@ -753,7 +762,13 @@ function ContentEditPage() {
 			data?: Record<string, unknown>;
 			slug?: string;
 			bylines?: BylineCreditInput[];
-		}) => updateContent(collection, id, { ...data, skipRevision: true }),
+		}) =>
+			updateContent(
+				collection,
+				id,
+				{ ...data, skipRevision: true },
+				{ locale: rawItem?.locale ?? activeLocale },
+			),
 		onSuccess: (savedItem, variables) => {
 			patchAutosaveQueries(queryClient, {
 				collection,
@@ -763,6 +778,7 @@ function ContentEditPage() {
 					data: variables.data,
 					slug: variables.slug,
 				},
+				locale: rawItem?.locale ?? activeLocale,
 			});
 			setLastAutosaveAt(new Date());
 			// Keep the cache fresh without refetching older server state back into the form
@@ -778,9 +794,11 @@ function ContentEditPage() {
 	});
 
 	const publishMutation = useMutation({
-		mutationFn: () => publishContent(collection, id),
+		mutationFn: () => publishContent(collection, id, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
-			void queryClient.invalidateQueries({ queryKey: ["content", collection, id] });
+			void queryClient.invalidateQueries({
+				queryKey: ["content", collection, id, { locale: rawItem?.locale ?? activeLocale }],
+			});
 			void queryClient.invalidateQueries({ queryKey: ["revisions", collection, id] });
 			toastManager.add({ title: t`Published`, description: t`Content is now live` });
 		},
@@ -794,9 +812,11 @@ function ContentEditPage() {
 	});
 
 	const unpublishMutation = useMutation({
-		mutationFn: () => unpublishContent(collection, id),
+		mutationFn: () => unpublishContent(collection, id, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
-			void queryClient.invalidateQueries({ queryKey: ["content", collection, id] });
+			void queryClient.invalidateQueries({
+				queryKey: ["content", collection, id, { locale: rawItem?.locale ?? activeLocale }],
+			});
 			void queryClient.invalidateQueries({ queryKey: ["revisions", collection, id] });
 			toastManager.add({ title: t`Unpublished`, description: t`Content removed from public view` });
 		},
@@ -810,9 +830,11 @@ function ContentEditPage() {
 	});
 
 	const discardDraftMutation = useMutation({
-		mutationFn: () => discardDraft(collection, id),
+		mutationFn: () => discardDraft(collection, id, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
-			void queryClient.invalidateQueries({ queryKey: ["content", collection, id] });
+			void queryClient.invalidateQueries({
+				queryKey: ["content", collection, id, { locale: rawItem?.locale ?? activeLocale }],
+			});
 			void queryClient.invalidateQueries({ queryKey: ["revisions", collection, id] });
 			toastManager.add({
 				title: t`Changes discarded`,
@@ -829,9 +851,12 @@ function ContentEditPage() {
 	});
 
 	const scheduleMutation = useMutation({
-		mutationFn: (scheduledAt: string) => scheduleContent(collection, id, scheduledAt),
+		mutationFn: (scheduledAt: string) =>
+			scheduleContent(collection, id, scheduledAt, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
-			void queryClient.invalidateQueries({ queryKey: ["content", collection, id] });
+			void queryClient.invalidateQueries({
+				queryKey: ["content", collection, id, { locale: rawItem?.locale ?? activeLocale }],
+			});
 			toastManager.add({
 				title: t`Scheduled`,
 				description: t`Content has been scheduled for publishing`,
@@ -847,9 +872,12 @@ function ContentEditPage() {
 	});
 
 	const unscheduleMutation = useMutation({
-		mutationFn: () => unscheduleContent(collection, id),
+		mutationFn: () =>
+			unscheduleContent(collection, id, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
-			void queryClient.invalidateQueries({ queryKey: ["content", collection, id] });
+			void queryClient.invalidateQueries({
+				queryKey: ["content", collection, id, { locale: rawItem?.locale ?? activeLocale }],
+			});
 			toastManager.add({
 				title: t`Unscheduled`,
 				description: t`Content reverted to draft`,
@@ -879,6 +907,7 @@ function ContentEditPage() {
 			void navigate({
 				to: "/content/$collection/$id",
 				params: { collection, id: result.id },
+				search: { locale: result.locale },
 			});
 			toastManager.add({
 				title: t`Translation created`,
@@ -895,14 +924,14 @@ function ContentEditPage() {
 	});
 
 	const deleteMutation = useMutation({
-		mutationFn: () => deleteContent(collection, id),
+		mutationFn: () => deleteContent(collection, id, { locale: rawItem?.locale ?? activeLocale }),
 		onSuccess: () => {
 			void queryClient.invalidateQueries({ queryKey: ["content", collection] });
 			void queryClient.invalidateQueries({ queryKey: ["content", collection, "trash"] });
 			void navigate({
 				to: "/content/$collection",
 				params: { collection },
-				search: { locale: undefined },
+				search: { locale: activeLocale },
 			});
 		},
 		onError: (error) => {
diff --git a/packages/core/src/astro/routes/api/content/[collection]/[id].ts b/packages/core/src/astro/routes/api/content/[collection]/[id].ts
index e17b16bce..49b4b388a 100644
--- a/packages/core/src/astro/routes/api/content/[collection]/[id].ts
+++ b/packages/core/src/astro/routes/api/content/[collection]/[id].ts
@@ -64,7 +64,7 @@ export const GET: APIRoute = async ({ params, url, locals }) => {
 	return unwrapResult(result);
 };
 
-export const PUT: APIRoute = async ({ params, request, locals, cache }) => {
+export const PUT: APIRoute = async ({ params, request, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -76,6 +76,8 @@ export const PUT: APIRoute = async ({ params, request, locals, cache }) => {
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
 	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
@@ -132,7 +134,7 @@ export const PUT: APIRoute = async ({ params, request, locals, cache }) => {
 	return unwrapResult(result);
 };
 
-export const DELETE: APIRoute = async ({ params, locals, cache }) => {
+export const DELETE: APIRoute = async ({ params, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -141,8 +143,10 @@ export const DELETE: APIRoute = async ({ params, locals, cache }) => {
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
-	const existing = await emdash.handleContentGet(collection, id);
+	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
 		return apiError(
 			existing.error?.code ?? "UNKNOWN_ERROR",
diff --git a/packages/core/src/astro/routes/api/content/[collection]/[id]/discard-draft.ts b/packages/core/src/astro/routes/api/content/[collection]/[id]/discard-draft.ts
index 321d7d21e..8433a60ae 100644
--- a/packages/core/src/astro/routes/api/content/[collection]/[id]/discard-draft.ts
+++ b/packages/core/src/astro/routes/api/content/[collection]/[id]/discard-draft.ts
@@ -11,7 +11,7 @@ import { apiError, mapErrorStatus, unwrapResult } from "#api/error.js";
 
 export const prerender = false;
 
-export const POST: APIRoute = async ({ params, locals, cache }) => {
+export const POST: APIRoute = async ({ params, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -20,8 +20,10 @@ export const POST: APIRoute = async ({ params, locals, cache }) => {
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
-	const existing = await emdash.handleContentGet(collection, id);
+	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
 		return apiError(
 			existing.error?.code ?? "UNKNOWN_ERROR",
diff --git a/packages/core/src/astro/routes/api/content/[collection]/[id]/publish.ts b/packages/core/src/astro/routes/api/content/[collection]/[id]/publish.ts
index 8a80e6c6e..636e5f64a 100644
--- a/packages/core/src/astro/routes/api/content/[collection]/[id]/publish.ts
+++ b/packages/core/src/astro/routes/api/content/[collection]/[id]/publish.ts
@@ -20,7 +20,7 @@ import { contentPublishBody } from "#api/schemas.js";
 
 export const prerender = false;
 
-export const POST: APIRoute = async ({ params, request, locals, cache }) => {
+export const POST: APIRoute = async ({ params, request, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -34,8 +34,10 @@ export const POST: APIRoute = async ({ params, request, locals, cache }) => {
 	const body = await parseOptionalBody(request, contentPublishBody, {});
 	if (isParseError(body)) return body;
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
-	const existing = await emdash.handleContentGet(collection, id);
+	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
 		return apiError(
 			existing.error?.code ?? "UNKNOWN_ERROR",
diff --git a/packages/core/src/astro/routes/api/content/[collection]/[id]/schedule.ts b/packages/core/src/astro/routes/api/content/[collection]/[id]/schedule.ts
index 74a0dd5aa..e833a826b 100644
--- a/packages/core/src/astro/routes/api/content/[collection]/[id]/schedule.ts
+++ b/packages/core/src/astro/routes/api/content/[collection]/[id]/schedule.ts
@@ -34,7 +34,7 @@ function extractOwnership(data: unknown): { authorId: string; resolvedId: string
 	};
 }
 
-export const POST: APIRoute = async ({ params, request, locals, cache }) => {
+export const POST: APIRoute = async ({ params, request, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -45,8 +45,10 @@ export const POST: APIRoute = async ({ params, request, locals, cache }) => {
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
-	const existing = await emdash.handleContentGet(collection, id);
+	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
 		return apiError(
 			existing.error?.code ?? "UNKNOWN_ERROR",
@@ -68,7 +70,7 @@ export const POST: APIRoute = async ({ params, request, locals, cache }) => {
 	return unwrapResult(result);
 };
 
-export const DELETE: APIRoute = async ({ params, locals, cache }) => {
+export const DELETE: APIRoute = async ({ params, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -77,8 +79,10 @@ export const DELETE: APIRoute = async ({ params, locals, cache }) => {
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
-	const existing = await emdash.handleContentGet(collection, id);
+	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
 		return apiError(
 			existing.error?.code ?? "UNKNOWN_ERROR",
diff --git a/packages/core/src/astro/routes/api/content/[collection]/[id]/unpublish.ts b/packages/core/src/astro/routes/api/content/[collection]/[id]/unpublish.ts
index 1092612e2..5f62e0652 100644
--- a/packages/core/src/astro/routes/api/content/[collection]/[id]/unpublish.ts
+++ b/packages/core/src/astro/routes/api/content/[collection]/[id]/unpublish.ts
@@ -11,7 +11,7 @@ import { apiError, mapErrorStatus, unwrapResult } from "#api/error.js";
 
 export const prerender = false;
 
-export const POST: APIRoute = async ({ params, locals, cache }) => {
+export const POST: APIRoute = async ({ params, locals, url, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -20,8 +20,10 @@ export const POST: APIRoute = async ({ params, locals, cache }) => {
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
+	const locale = url.searchParams.get("locale") || undefined;
+
 	// Fetch item to check ownership
-	const existing = await emdash.handleContentGet(collection, id);
+	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {
 		return apiError(
 			existing.error?.code ?? "UNKNOWN_ERROR",
diff --git a/packages/core/tests/unit/api/content-route-permissions.test.ts b/packages/core/tests/unit/api/content-route-permissions.test.ts
index 05d524952..be21f3d64 100644
--- a/packages/core/tests/unit/api/content-route-permissions.test.ts
+++ b/packages/core/tests/unit/api/content-route-permissions.test.ts
@@ -180,6 +180,7 @@ describe("content route — publishedAt / createdAt permission gate", () => {
 			const response = await updateContent({
 				params: { collection: "post", id: "c1" },
 				request,
+				url: new URL(request.url),
 				locals: {
 					emdash: { handleContentUpdate, handleContentGet },
 					user: makeUser(Role.AUTHOR),
@@ -204,6 +205,7 @@ describe("content route — publishedAt / createdAt permission gate", () => {
 			const response = await updateContent({
 				params: { collection: "post", id: "c1" },
 				request,
+				url: new URL(request.url),
 				locals: {
 					emdash: { handleContentUpdate, handleContentGet },
 					user: makeUser(Role.AUTHOR),
@@ -234,6 +236,7 @@ describe("content route — publishedAt / createdAt permission gate", () => {
 			const response = await updateContent({
 				params: { collection: "post", id: "c1" },
 				request,
+				url: new URL(request.url),
 				locals: {
 					emdash: { handleContentUpdate, handleContentGet },
 					user: makeUser(Role.EDITOR),
@@ -265,6 +268,7 @@ describe("content route — publishedAt / createdAt permission gate", () => {
 			const response = await updateContent({
 				params: { collection: "post", id: "c1" },
 				request,
+				url: new URL(request.url),
 				locals: {
 					emdash: { handleContentUpdate, handleContentGet },
 					user: makeUser(Role.AUTHOR),
diff --git a/packages/core/tests/unit/astro/content-route-locale.test.ts b/packages/core/tests/unit/astro/content-route-locale.test.ts
new file mode 100644
index 000000000..17e33abc1
--- /dev/null
+++ b/packages/core/tests/unit/astro/content-route-locale.test.ts
@@ -0,0 +1,238 @@
+/**
+ * Content route locale forwarding.
+ *
+ * When a ?locale query param is present, single-item write routes must
+ * forward it to handleContentGet so slug-based lookups resolve to the
+ * correct i18n variant instead of returning the first matching row.
+ */
+
+import { Role } from "@emdash-cms/auth";
+import type { APIContext } from "astro";
+import { describe, it, expect, vi } from "vitest";
+
+import {
+	PUT as putItem,
+	DELETE as deleteItem,
+} from "../../../src/astro/routes/api/content/[collection]/[id].js";
+import { POST as postDiscard } from "../../../src/astro/routes/api/content/[collection]/[id]/discard-draft.js";
+import { POST as postPublish } from "../../../src/astro/routes/api/content/[collection]/[id]/publish.js";
+import {
+	POST as postSchedule,
+	DELETE as deleteSchedule,
+} from "../../../src/astro/routes/api/content/[collection]/[id]/schedule.js";
+import { POST as postUnpublish } from "../../../src/astro/routes/api/content/[collection]/[id]/unpublish.js";
+
+const editor = { id: "u-edit", role: Role.EDITOR };
+
+function buildEmdash() {
+	const handleContentGet = vi.fn(async (_collection: string, _id: string, _locale?: string) => ({
+		success: true as const,
+		data: {
+			item: {
+				id: "resolved-id",
+				type: "post",
+				slug: "hello",
+				status: "published",
+				data: {},
+				authorId: "u-edit",
+				primaryBylineId: null,
+				createdAt: "2026-01-01T00:00:00Z",
+				updatedAt: "2026-01-01T00:00:00Z",
+				publishedAt: "2026-01-01T00:00:00Z",
+				scheduledAt: null,
+				liveRevisionId: null,
+				draftRevisionId: null,
+				version: 1,
+				locale: "en",
+				translationGroup: "tg-1",
+			},
+			_rev: "rev1",
+		},
+	}));
+
+	const handleContentUpdate = vi.fn(async () => ({
+		success: true as const,
+		data: { item: { id: "resolved-id" } },
+	}));
+
+	const handleContentDelete = vi.fn(async () => ({
+		success: true as const,
+		data: { deleted: true },
+	}));
+
+	const handleContentPublish = vi.fn(async () => ({
+		success: true as const,
+		data: { item: { id: "resolved-id" } },
+	}));
+
+	const handleContentUnpublish = vi.fn(async () => ({
+		success: true as const,
+		data: { item: { id: "resolved-id" } },
+	}));
+
+	const handleContentDiscardDraft = vi.fn(async () => ({
+		success: true as const,
+		data: { item: { id: "resolved-id" } },
+	}));
+
+	const handleContentSchedule = vi.fn(async () => ({
+		success: true as const,
+		data: { item: { id: "resolved-id" } },
+	}));
+
+	const handleContentUnschedule = vi.fn(async () => ({
+		success: true as const,
+		data: { item: { id: "resolved-id" } },
+	}));
+
+	return {
+		handleContentGet,
+		handleContentUpdate,
+		handleContentDelete,
+		handleContentPublish,
+		handleContentUnpublish,
+		handleContentDiscardDraft,
+		handleContentSchedule,
+		handleContentUnschedule,
+	};
+}
+
+function ctx(opts: {
+	user: typeof editor;
+	emdash: ReturnType<typeof buildEmdash>;
+	method?: string;
+	body?: unknown;
+	url?: string;
+}): APIContext {
+	const url = new URL(opts.url ?? "http://localhost/_emdash/api/content/post/hello");
+	const request = new Request(url, {
+		method: opts.method ?? "GET",
+		headers: { "content-type": "application/json" },
+		body: opts.body ? JSON.stringify(opts.body) : undefined,
+	});
+	return {
+		params: { collection: "post", id: "hello" },
+		url,
+		request,
+		locals: {
+			user: opts.user,
+			emdash: opts.emdash,
+		},
+		cache: { enabled: false, invalidate: vi.fn() },
+		// eslint-disable-next-line typescript/no-unsafe-type-assertion -- minimal stub for tests
+	} as unknown as APIContext;
+}
+
+describe("PUT /content/:collection/:id forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await putItem(
+			ctx({
+				user: editor,
+				emdash,
+				method: "PUT",
+				body: { data: { title: "Updated" } },
+				url: "http://localhost/_emdash/api/content/post/hello?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});
+
+describe("DELETE /content/:collection/:id forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await deleteItem(
+			ctx({
+				user: editor,
+				emdash,
+				method: "DELETE",
+				url: "http://localhost/_emdash/api/content/post/hello?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});
+
+describe("POST /content/:collection/:id/publish forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await postPublish(
+			ctx({
+				user: editor,
+				emdash,
+				method: "POST",
+				url: "http://localhost/_emdash/api/content/post/hello/publish?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});
+
+describe("POST /content/:collection/:id/unpublish forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await postUnpublish(
+			ctx({
+				user: editor,
+				emdash,
+				method: "POST",
+				url: "http://localhost/_emdash/api/content/post/hello/unpublish?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});
+
+describe("POST /content/:collection/:id/discard-draft forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await postDiscard(
+			ctx({
+				user: editor,
+				emdash,
+				method: "POST",
+				url: "http://localhost/_emdash/api/content/post/hello/discard-draft?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});
+
+describe("POST /content/:collection/:id/schedule forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await postSchedule(
+			ctx({
+				user: editor,
+				emdash,
+				method: "POST",
+				body: { scheduledAt: "2026-12-31T23:59:59Z" },
+				url: "http://localhost/_emdash/api/content/post/hello/schedule?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});
+
+describe("DELETE /content/:collection/:id/schedule forwards locale to handleContentGet", () => {
+	it("passes locale=en when query param is present", async () => {
+		const emdash = buildEmdash();
+		const res = await deleteSchedule(
+			ctx({
+				user: editor,
+				emdash,
+				method: "DELETE",
+				url: "http://localhost/_emdash/api/content/post/hello/schedule?locale=en",
+			}),
+		);
+		expect(res.status).toBe(200);
+		expect(emdash.handleContentGet).toHaveBeenCalledWith("post", "hello", "en");
+	});
+});

From 561c99310160a5492ef71a40d7956e69b2842c24 Mon Sep 17 00:00:00 2001
From: Matt Kane <m@mk.gg>
Date: Wed, 3 Jun 2026 20:22:17 +0100
Subject: [PATCH 2/3] fix(admin): carry locale through new-content save
 navigation

The create-new flow navigated to the edit route without a locale search
param, while edit links and translation navigation now append one. That
asymmetry made the i18n e2e test's full-URL equality assertion fail when
navigating back to the default-locale entry.
---
 packages/admin/src/router.tsx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/admin/src/router.tsx b/packages/admin/src/router.tsx
index eba0f5e4b..28379e37d 100644
--- a/packages/admin/src/router.tsx
+++ b/packages/admin/src/router.tsx
@@ -497,6 +497,7 @@ function ContentNewPage() {
 			void navigate({
 				to: "/content/$collection/$id",
 				params: { collection, id: result.id },
+				search: { locale: result.locale },
 			});
 		},
 	});

From b238b6e8cb177f26ed87a5c2eceb6c1eb87d0869 Mon Sep 17 00:00:00 2001
From: Matt Kane <m@mk.gg>
Date: Wed, 3 Jun 2026 20:59:06 +0100
Subject: [PATCH 3/3] fix(core): resolve locale-update overlap with #1302 after
 rebase

Main's #1302 already added locale reading to the PUT content-update
route. Drop this branch's duplicate declaration (kept main's
request.url form, which the existing route test exercises) so the
merged PUT handler has a single `locale`. The branch's remaining core
contribution is locale on DELETE and the publish/unpublish/schedule/
discard-draft sub-action routes.
---
 .changeset/fix-core-locale-write.md                           | 2 +-
 .../core/src/astro/routes/api/content/[collection]/[id].ts    | 4 +---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/.changeset/fix-core-locale-write.md b/.changeset/fix-core-locale-write.md
index 743513214..ea65edb1c 100644
--- a/.changeset/fix-core-locale-write.md
+++ b/.changeset/fix-core-locale-write.md
@@ -2,4 +2,4 @@
 "emdash": patch
 ---
 
-Read `?locale=` in content write routes (PUT, DELETE, publish, unpublish, discard-draft, schedule, unschedule) and forward it to `handleContentGet` for locale-aware slug resolution (#1242)
+Read `?locale=` in content write routes (DELETE, publish, unpublish, discard-draft, schedule, unschedule) and forward it to `handleContentGet` for locale-aware slug resolution (#1242)
diff --git a/packages/core/src/astro/routes/api/content/[collection]/[id].ts b/packages/core/src/astro/routes/api/content/[collection]/[id].ts
index 49b4b388a..16374bd63 100644
--- a/packages/core/src/astro/routes/api/content/[collection]/[id].ts
+++ b/packages/core/src/astro/routes/api/content/[collection]/[id].ts
@@ -64,7 +64,7 @@ export const GET: APIRoute = async ({ params, url, locals }) => {
 	return unwrapResult(result);
 };
 
-export const PUT: APIRoute = async ({ params, request, locals, url, cache }) => {
+export const PUT: APIRoute = async ({ params, request, locals, cache }) => {
 	const { emdash, user } = locals;
 	const collection = params.collection!;
 	const id = params.id!;
@@ -76,8 +76,6 @@ export const PUT: APIRoute = async ({ params, request, locals, url, cache }) =>
 		return apiError("NOT_CONFIGURED", "EmDash is not initialized", 500);
 	}
 
-	const locale = url.searchParams.get("locale") || undefined;
-
 	// Fetch item to check ownership
 	const existing = await emdash.handleContentGet(collection, id, locale);
 	if (!existing.success) {