diff --git a/web/app/components/datasets/documents/detail/metadata/hooks/use-metadata-state.ts b/web/app/components/datasets/documents/detail/metadata/hooks/use-metadata-state.ts
index 5f7aa4289d..08651b699e 100644
--- a/web/app/components/datasets/documents/detail/metadata/hooks/use-metadata-state.ts
+++ b/web/app/components/datasets/documents/detail/metadata/hooks/use-metadata-state.ts
@@ -89,7 +89,7 @@ export function useMetadataState({ docDetail, onUpdate }: UseMetadataStateOption
   }
 
   const cancelEdit = () => {
-    setMetadataParams({ documentType: docType || '', metadata: { ...docDetail?.doc_metadata } })
+    setMetadataParams({ documentType: docType || '', metadata: { ...(docDetail?.doc_metadata || {}) } })
     setEditStatus(!docType)
     if (!docType)
       setShowDocTypes(true)
diff --git a/web/app/components/rag-pipeline/hooks/use-update-dsl-modal.ts b/web/app/components/rag-pipeline/hooks/use-update-dsl-modal.ts
index 065a6b4ca5..3b86937417 100644
--- a/web/app/components/rag-pipeline/hooks/use-update-dsl-modal.ts
+++ b/web/app/components/rag-pipeline/hooks/use-update-dsl-modal.ts
@@ -97,7 +97,7 @@ export const useUpdateDSLModal = ({ onCancel, onImport }: UseUpdateDSLModalParam
         hash,
         rag_pipeline_variables: rag_pipeline_variables || [],
       },
-    } as unknown as string)
+    })
   }, [eventEmitter])
 
   const completeImport = useCallback(async (
diff --git a/web/context/event-emitter.tsx b/web/context/event-emitter.tsx
index 61a605cabf..14b81eacb6 100644
--- a/web/context/event-emitter.tsx
+++ b/web/context/event-emitter.tsx
@@ -4,7 +4,19 @@ import type { EventEmitter } from 'ahooks/lib/useEventEmitter'
 import { useEventEmitter } from 'ahooks'
 import { createContext, useContext } from 'use-context-selector'
 
-const EventEmitterContext = createContext<{ eventEmitter: EventEmitter<string> | null }>({
+/**
+ * Typed event object emitted via the shared EventEmitter.
+ * Covers workflow updates, prompt-editor commands, DSL export checks, etc.
+ */
+export type EventEmitterMessage = {
+  type: string
+  payload?: unknown
+  instanceId?: string
+}
+
+export type EventEmitterValue = string | EventEmitterMessage
+
+const EventEmitterContext = createContext<{ eventEmitter: EventEmitter<EventEmitterValue> | null }>({
   eventEmitter: null,
 })
 
@@ -16,7 +28,7 @@ type EventEmitterContextProviderProps = {
 export const EventEmitterContextProvider = ({
   children,
 }: EventEmitterContextProviderProps) => {
-  const eventEmitter = useEventEmitter<string>()
+  const eventEmitter = useEventEmitter<EventEmitterValue>()
 
   return (
     <EventEmitterContext.Provider value={{ eventEmitter }}>