diff --git a/src/lib/api/mutations/grid.mutations.ts b/src/lib/api/mutations/grid.mutations.ts
index 70ca02cf..945fbab7 100644
--- a/src/lib/api/mutations/grid.mutations.ts
+++ b/src/lib/api/mutations/grid.mutations.ts
@@ -19,6 +19,36 @@ import {
 } from '$lib/api/adapters/grid.adapter'
 import { partyKeys } from '$lib/api/queries/party.queries'
 import type { Party, GridWeapon, GridCharacter, GridSummon } from '$lib/types/api/party'
+import { getEditKey } from '$lib/utils/editKeys'
+
+// ============================================================================
+// Mutation Factory
+// ============================================================================
+
+/**
+ * Wraps a grid adapter method to automatically inject edit key headers for anonymous users.
+ * When a party has an edit key stored in localStorage, it's automatically sent in the X-Edit-Key header.
+ *
+ * For anonymous users:
+ * - Edit key is retrieved from localStorage using party shortcode
+ * - X-Edit-Key header is automatically injected
+ *
+ * For authenticated users:
+ * - No edit key in localStorage
+ * - Falls back to Bearer token (existing behavior)
+ *
+ * @param adapterMethod - The grid adapter method to wrap
+ * @returns Wrapped method that automatically handles edit key injection
+ */
+function createGridMutation<TParams extends { partyId: number | string }>(
+	adapterMethod: (params: TParams, headers?: Record<string, string>) => Promise<any>
+) {
+	return (params: TParams) => {
+		const editKey = typeof params.partyId === 'string' ? getEditKey(params.partyId) : null
+		const headers = editKey ? { 'X-Edit-Key': editKey } : undefined
+		return adapterMethod(params, headers)
+	}
+}
 
 // ============================================================================
 // Weapon Mutations
@@ -50,7 +80,9 @@ export function useCreateGridWeapon() {
 	const queryClient = useQueryClient()
 
 	return createMutation(() => ({
-		mutationFn: (params: CreateGridWeaponParams) => gridAdapter.createWeapon(params),
+		mutationFn: createGridMutation((params: CreateGridWeaponParams, headers?: Record<string, string>) =>
+			gridAdapter.createWeapon(params, headers)
+		),
 		onSuccess: (_data, params) => {
 			// Invalidate the party to refetch with new weapon
 			queryClient.invalidateQueries({ queryKey: partyKeys.detail(params.partyId) })
@@ -245,7 +277,9 @@ export function useCreateGridCharacter() {
 	const queryClient = useQueryClient()
 
 	return createMutation(() => ({
-		mutationFn: (params: CreateGridCharacterParams) => gridAdapter.createCharacter(params),
+		mutationFn: createGridMutation((params: CreateGridCharacterParams, headers?: Record<string, string>) =>
+			gridAdapter.createCharacter(params, headers)
+		),
 		onSuccess: (_data, params) => {
 			queryClient.invalidateQueries({ queryKey: partyKeys.detail(params.partyId) })
 		}
@@ -422,7 +456,9 @@ export function useCreateGridSummon() {
 	const queryClient = useQueryClient()
 
 	return createMutation(() => ({
-		mutationFn: (params: CreateGridSummonParams) => gridAdapter.createSummon(params),
+		mutationFn: createGridMutation((params: CreateGridSummonParams, headers?: Record<string, string>) =>
+			gridAdapter.createSummon(params, headers)
+		),
 		onSuccess: (_data, params) => {
 			queryClient.invalidateQueries({ queryKey: partyKeys.detail(params.partyId) })
 		}
diff --git a/src/routes/teams/new/+page.svelte b/src/routes/teams/new/+page.svelte
index 806d5993..f9fd7455 100644
--- a/src/routes/teams/new/+page.svelte
+++ b/src/routes/teams/new/+page.svelte
@@ -11,6 +11,7 @@
   import type { SearchResult } from '$lib/api/adapters'
   import { partyAdapter, gridAdapter } from '$lib/api/adapters'
   import { getLocalId } from '$lib/utils/localId'
+  import { storeEditKey } from '$lib/utils/editKeys'
 
   // TanStack Query mutations
   import { useCreateParty } from '$lib/api/mutations/party.mutations'
@@ -136,6 +137,14 @@
         partyId = createdParty.id
         shortcode = createdParty.shortcode
 
+        // Store edit key for anonymous editing under BOTH identifiers
+        // - shortcode: for Party.svelte which uses shortcode as partyId
+        // - UUID: for /teams/new which uses UUID as partyId
+        if (createdParty.editKey) {
+          storeEditKey(createdParty.shortcode, createdParty.editKey)
+          storeEditKey(createdParty.id, createdParty.editKey)
+        }
+
         if (!partyId || !shortcode) {
           throw new Error('Party creation did not return ID or shortcode')
         }